- User events are finally ready!
After lots of collaboration between various parties, we finally locked
down on a stable interface for user events that can also work with user
space only tracing. This is implemented by telling the kernel (or user
space library, but that part is user space only and not part of this
patch set), where the variable is that the application uses to know if
something is listening to the trace. There's also an interface to tell
the kernel about these events, which will show up in the
/sys/kernel/tracing/events/user_events/ directory, where it can be
enabled. When it's enabled, the kernel will update the variable, to tell
the application to start writing to the kernel.
See https://lwn.net/Articles/927595/
- Cleaned up the direct trampolines code to simplify arm64 addition of
direct trampolines. Direct trampolines use the ftrace interface but
instead of jumping to the ftrace trampoline, applications (mostly BPF)
can register their own trampoline for performance reasons.
- Some updates to the fprobe infrastructure. fprobes are more efficient than
kprobes, as it does not need to save all the registers that kprobes on
ftrace do. More work needs to be done before the fprobes will be exposed
as dynamic events.
- More updates to references to the obsolete path of
/sys/kernel/debug/tracing for the new /sys/kernel/tracing path.
- Add a seq_buf_do_printk() helper to seq_bufs, to print a large buffer line
by line instead of all at once. There's users in production kernels that
have a large data dump that originally used printk() directly, but the
data dump was larger than what printk() allowed as a single print.
Using seq_buf() to do the printing fixes that.
- Add /sys/kernel/tracing/touched_functions that shows all functions that
was every traced by ftrace or a direct trampoline. This is used for
debugging issues where a traced function could have caused a crash by
a bpf program or live patching.
- Add a "fields" option that is similar to "raw" but outputs the fields of
the events. It's easier to read by humans.
- Some minor fixes and clean ups.
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Merge tag 'trace-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
- User events are finally ready!
After lots of collaboration between various parties, we finally
locked down on a stable interface for user events that can also work
with user space only tracing.
This is implemented by telling the kernel (or user space library, but
that part is user space only and not part of this patch set), where
the variable is that the application uses to know if something is
listening to the trace.
There's also an interface to tell the kernel about these events,
which will show up in the /sys/kernel/tracing/events/user_events/
directory, where it can be enabled.
When it's enabled, the kernel will update the variable, to tell the
application to start writing to the kernel.
See https://lwn.net/Articles/927595/
- Cleaned up the direct trampolines code to simplify arm64 addition of
direct trampolines.
Direct trampolines use the ftrace interface but instead of jumping to
the ftrace trampoline, applications (mostly BPF) can register their
own trampoline for performance reasons.
- Some updates to the fprobe infrastructure. fprobes are more efficient
than kprobes, as it does not need to save all the registers that
kprobes on ftrace do. More work needs to be done before the fprobes
will be exposed as dynamic events.
- More updates to references to the obsolete path of
/sys/kernel/debug/tracing for the new /sys/kernel/tracing path.
- Add a seq_buf_do_printk() helper to seq_bufs, to print a large buffer
line by line instead of all at once.
There are users in production kernels that have a large data dump
that originally used printk() directly, but the data dump was larger
than what printk() allowed as a single print.
Using seq_buf() to do the printing fixes that.
- Add /sys/kernel/tracing/touched_functions that shows all functions
that was every traced by ftrace or a direct trampoline. This is used
for debugging issues where a traced function could have caused a
crash by a bpf program or live patching.
- Add a "fields" option that is similar to "raw" but outputs the fields
of the events. It's easier to read by humans.
- Some minor fixes and clean ups.
* tag 'trace-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (41 commits)
ring-buffer: Sync IRQ works before buffer destruction
tracing: Add missing spaces in trace_print_hex_seq()
ring-buffer: Ensure proper resetting of atomic variables in ring_buffer_reset_online_cpus
recordmcount: Fix memory leaks in the uwrite function
tracing/user_events: Limit max fault-in attempts
tracing/user_events: Prevent same address and bit per process
tracing/user_events: Ensure bit is cleared on unregister
tracing/user_events: Ensure write index cannot be negative
seq_buf: Add seq_buf_do_printk() helper
tracing: Fix print_fields() for __dyn_loc/__rel_loc
tracing/user_events: Set event filter_type from type
ring-buffer: Clearly check null ptr returned by rb_set_head_page()
tracing: Unbreak user events
tracing/user_events: Use print_format_fields() for trace output
tracing/user_events: Align structs with tabs for readability
tracing/user_events: Limit global user_event count
tracing/user_events: Charge event allocs to cgroups
tracing/user_events: Update documentation for ABI
tracing/user_events: Use write ABI in example
tracing/user_events: Add ABI self-test
...
During tracefs discussions it was decided instead of requiring a mapping
within a user-process to track the lifetime of memory descriptors we
should hook the appropriate calls. Do this by adding the minimal stubs
required for task fork, exec, and exit. Currently this is just a NOP.
Future patches will implement these calls fully.
Link: https://lkml.kernel.org/r/20230328235219.203-3-beaub@linux.microsoft.com
Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add explicit _lazy_tlb annotated functions for lazy tlb mm refcounting.
This makes the lazy tlb mm references more obvious, and allows the
refcounting scheme to be modified in later changes. There is no
functional change with this patch.
Link: https://lkml.kernel.org/r/20230203071837.1136453-3-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
- Support for arm64 SME 2 and 2.1. SME2 introduces a new 512-bit
architectural register (ZT0, for the look-up table feature) that Linux
needs to save/restore.
- Include TPIDR2 in the signal context and add the corresponding
kselftests.
- Perf updates: Arm SPEv1.2 support, HiSilicon uncore PMU updates, ACPI
support to the Marvell DDR and TAD PMU drivers, reset DTM_PMU_CONFIG
(ARM CMN) at probe time.
- Support for DYNAMIC_FTRACE_WITH_CALL_OPS on arm64.
- Permit EFI boot with MMU and caches on. Instead of cleaning the entire
loaded kernel image to the PoC and disabling the MMU and caches before
branching to the kernel bare metal entry point, leave the MMU and
caches enabled and rely on EFI's cacheable 1:1 mapping of all of
system RAM to populate the initial page tables.
- Expose the AArch32 (compat) ELF_HWCAP features to user in an arm64
kernel (the arm32 kernel only defines the values).
- Harden the arm64 shadow call stack pointer handling: stash the shadow
stack pointer in the task struct on interrupt, load it directly from
this structure.
- Signal handling cleanups to remove redundant validation of size
information and avoid reading the same data from userspace twice.
- Refactor the hwcap macros to make use of the automatically generated
ID registers. It should make new hwcaps writing less error prone.
- Further arm64 sysreg conversion and some fixes.
- arm64 kselftest fixes and improvements.
- Pointer authentication cleanups: don't sign leaf functions, unify
asm-arch manipulation.
- Pseudo-NMI code generation optimisations.
- Minor fixes for SME and TPIDR2 handling.
- Miscellaneous updates: ARCH_FORCE_MAX_ORDER is now selectable, replace
strtobool() to kstrtobool() in the cpufeature.c code, apply dynamic
shadow call stack in two passes, intercept pfn changes in set_pte_at()
without the required break-before-make sequence, attempt to dump all
instructions on unhandled kernel faults.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
- Support for arm64 SME 2 and 2.1. SME2 introduces a new 512-bit
architectural register (ZT0, for the look-up table feature) that
Linux needs to save/restore
- Include TPIDR2 in the signal context and add the corresponding
kselftests
- Perf updates: Arm SPEv1.2 support, HiSilicon uncore PMU updates, ACPI
support to the Marvell DDR and TAD PMU drivers, reset DTM_PMU_CONFIG
(ARM CMN) at probe time
- Support for DYNAMIC_FTRACE_WITH_CALL_OPS on arm64
- Permit EFI boot with MMU and caches on. Instead of cleaning the
entire loaded kernel image to the PoC and disabling the MMU and
caches before branching to the kernel bare metal entry point, leave
the MMU and caches enabled and rely on EFI's cacheable 1:1 mapping of
all of system RAM to populate the initial page tables
- Expose the AArch32 (compat) ELF_HWCAP features to user in an arm64
kernel (the arm32 kernel only defines the values)
- Harden the arm64 shadow call stack pointer handling: stash the shadow
stack pointer in the task struct on interrupt, load it directly from
this structure
- Signal handling cleanups to remove redundant validation of size
information and avoid reading the same data from userspace twice
- Refactor the hwcap macros to make use of the automatically generated
ID registers. It should make new hwcaps writing less error prone
- Further arm64 sysreg conversion and some fixes
- arm64 kselftest fixes and improvements
- Pointer authentication cleanups: don't sign leaf functions, unify
asm-arch manipulation
- Pseudo-NMI code generation optimisations
- Minor fixes for SME and TPIDR2 handling
- Miscellaneous updates: ARCH_FORCE_MAX_ORDER is now selectable,
replace strtobool() to kstrtobool() in the cpufeature.c code, apply
dynamic shadow call stack in two passes, intercept pfn changes in
set_pte_at() without the required break-before-make sequence, attempt
to dump all instructions on unhandled kernel faults
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (130 commits)
arm64: fix .idmap.text assertion for large kernels
kselftest/arm64: Don't require FA64 for streaming SVE+ZA tests
kselftest/arm64: Copy whole EXTRA context
arm64: kprobes: Drop ID map text from kprobes blacklist
perf: arm_spe: Print the version of SPE detected
perf: arm_spe: Add support for SPEv1.2 inverted event filtering
perf: Add perf_event_attr::config3
arm64/sme: Fix __finalise_el2 SMEver check
drivers/perf: fsl_imx8_ddr_perf: Remove set-but-not-used variable
arm64/signal: Only read new data when parsing the ZT context
arm64/signal: Only read new data when parsing the ZA context
arm64/signal: Only read new data when parsing the SVE context
arm64/signal: Avoid rereading context frame sizes
arm64/signal: Make interface for restore_fpsimd_context() consistent
arm64/signal: Remove redundant size validation from parse_user_sigframe()
arm64/signal: Don't redundantly verify FPSIMD magic
arm64/cpufeature: Use helper macros to specify hwcaps
arm64/cpufeature: Always use symbolic name for feature value in hwcaps
arm64/sysreg: Initial unsigned annotations for ID registers
arm64/sysreg: Initial annotation of signed ID registers
...
Contemporary versions of GCC (e.g. GCC 12.2.0) drop the alignment
specified by '-falign-functions=N' for functions marked with the
__cold__ attribute, and potentially for callees of __cold__ functions as
these may be implicitly marked as __cold__ by the compiler. LLVM appears
to respect '-falign-functions=N' in such cases.
This has been reported to GCC in bug 88345:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88345
... which also covers alignment being dropped when '-Os' is used, which
will be addressed in a separate patch.
Currently, use of '-falign-functions=N' is limited to
CONFIG_FUNCTION_ALIGNMENT, which is largely used for performance and/or
analysis reasons (e.g. with CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B), but
isn't necessary for correct functionality. However, this dropped
alignment isn't great for the performance and/or analysis cases.
Subsequent patches will use CONFIG_FUNCTION_ALIGNMENT as part of arm64's
ftrace implementation, which will require all instrumented functions to
be aligned to at least 8-bytes.
This patch works around the dropped alignment by avoiding the use of the
__cold__ attribute when CONFIG_FUNCTION_ALIGNMENT is non-zero, and by
specifically aligning abort(), which GCC implicitly marks as __cold__.
As the __cold macro is now dependent upon config options (which is
against the policy described at the top of compiler_attributes.h), it is
moved into compiler_types.h.
I've tested this by building and booting a kernel configured with
defconfig + CONFIG_EXPERT=y + CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B=y,
and looking for misaligned text symbols in /proc/kallsyms:
* arm64:
Before:
# uname -rm
6.2.0-rc3 aarch64
# grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l
5009
After:
# uname -rm
6.2.0-rc3-00001-g2a2bedf8bfa9 aarch64
# grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l
919
* x86_64:
Before:
# uname -rm
6.2.0-rc3 x86_64
# grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l
11537
After:
# uname -rm
6.2.0-rc3-00001-g2a2bedf8bfa9 x86_64
# grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l
2805
There's clearly a substantial reduction in the number of misaligned
symbols. From manual inspection, the remaining unaligned text labels are
a combination of ACPICA functions (due to the use of '-Os'), static call
trampolines, and non-function labels in assembly, which will be dealt
with in subsequent patches.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Deacon <will@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20230123134603.1064407-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
If a task oopses with irqs disabled, this can cause various cascading
problems in the oops path such as sleep-from-invalid warnings, and
potentially worse.
Since commit 0258b5fd7c ("coredump: Limit coredumps to a single
thread group"), the unconditional irq enable in coredump_task_exit()
will "fix" the irq state to be enabled early in do_exit(), so currently
this may not be triggerable, but that is coincidental and fragile.
Detect and fix the irqs_disabled() condition in the oops path before
calling do_exit(), similarly to the way in_atomic() is handled.
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/lkml/20221004094401.708299-1-npiggin@gmail.com/
Use a temporary variable to take full advantage of READ_ONCE() behavior.
Without this, the report (and even the test) might be out of sync with
the initial test.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/Y5x7GXeluFmZ8E0E@hirez.programming.kicks-ass.net
Fixes: 9fc9e278a5 ("panic: Introduce warn_limit")
Fixes: d4ccd54d28 ("exit: Put an upper limit on how often we can oops")
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jann Horn <jannh@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Marco Elver <elver@google.com>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Kees Cook <keescook@chromium.org>
Since Oops count is now tracked and is a fairly interesting signal, add
the entry /sys/kernel/oops_count to expose it to userspace.
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jann Horn <jannh@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-3-keescook@chromium.org
Many Linux systems are configured to not panic on oops; but allowing an
attacker to oops the system **really** often can make even bugs that look
completely unexploitable exploitable (like NULL dereferences and such) if
each crash elevates a refcount by one or a lock is taken in read mode, and
this causes a counter to eventually overflow.
The most interesting counters for this are 32 bits wide (like open-coded
refcounts that don't use refcount_t). (The ldsem reader count on 32-bit
platforms is just 16 bits, but probably nobody cares about 32-bit platforms
that much nowadays.)
So let's panic the system if the kernel is constantly oopsing.
The speed of oopsing 2^32 times probably depends on several factors, like
how long the stack trace is and which unwinder you're using; an empirically
important one is whether your console is showing a graphical environment or
a text console that oopses will be printed to.
In a quick single-threaded benchmark, it looks like oopsing in a vfork()
child with a very short stack trace only takes ~510 microseconds per run
when a graphical console is active; but switching to a text console that
oopses are printed to slows it down around 87x, to ~45 milliseconds per
run.
(Adding more threads makes this faster, but the actual oops printing
happens under &die_lock on x86, so you can maybe speed this up by a factor
of around 2 and then any further improvement gets eaten up by lock
contention.)
It looks like it would take around 8-12 days to overflow a 32-bit counter
with repeated oopsing on a multi-core X86 system running a graphical
environment; both me (in an X86 VM) and Seth (with a distro kernel on
normal hardware in a standard configuration) got numbers in that ballpark.
12 days aren't *that* short on a desktop system, and you'd likely need much
longer on a typical server system (assuming that people don't run graphical
desktop environments on their servers), and this is a *very* noisy and
violent approach to exploiting the kernel; and it also seems to take orders
of magnitude longer on some machines, probably because stuff like EFI
pstore will slow it down a ton if that's active.
Signed-off-by: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/r/20221107201317.324457-1-jannh@google.com
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-2-keescook@chromium.org
- Valentin Schneider makes crash-kexec work properly when invoked from
an NMI-time panic.
- ntfs bugfixes from Hawkins Jiawei
- Jiebin Sun improves IPC msg scalability by replacing atomic_t's with
percpu counters.
- nilfs2 cleanups from Minghao Chi
- lots of other single patches all over the tree!
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Merge tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- hfs and hfsplus kmap API modernization (Fabio Francesco)
- make crash-kexec work properly when invoked from an NMI-time panic
(Valentin Schneider)
- ntfs bugfixes (Hawkins Jiawei)
- improve IPC msg scalability by replacing atomic_t's with percpu
counters (Jiebin Sun)
- nilfs2 cleanups (Minghao Chi)
- lots of other single patches all over the tree!
* tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype
proc: test how it holds up with mapping'less process
mailmap: update Frank Rowand email address
ia64: mca: use strscpy() is more robust and safer
init/Kconfig: fix unmet direct dependencies
ia64: update config files
nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
fork: remove duplicate included header files
init/main.c: remove unnecessary (void*) conversions
proc: mark more files as permanent
nilfs2: remove the unneeded result variable
nilfs2: delete unnecessary checks before brelse()
checkpatch: warn for non-standard fixes tag style
usr/gen_init_cpio.c: remove unnecessary -1 values from int file
ipc/msg: mitigate the lock contention with percpu counter
percpu: add percpu_counter_add_local and percpu_counter_sub_local
fs/ocfs2: fix repeated words in comments
relay: use kvcalloc to alloc page array in relay_alloc_page_array
proc: make config PROC_CHILDREN depend on PROC_FS
fs: uninline inode_maybe_inc_iversion()
...
linux-next for a couple of months without, to my knowledge, any negative
reports (or any positive ones, come to that).
- Also the Maple Tree from Liam R. Howlett. An overlapping range-based
tree for vmas. It it apparently slight more efficient in its own right,
but is mainly targeted at enabling work to reduce mmap_lock contention.
Liam has identified a number of other tree users in the kernel which
could be beneficially onverted to mapletrees.
Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
(https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com).
This has yet to be addressed due to Liam's unfortunately timed
vacation. He is now back and we'll get this fixed up.
- Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
clang-generated instrumentation to detect used-unintialized bugs down to
the single bit level.
KMSAN keeps finding bugs. New ones, as well as the legacy ones.
- Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
memory into THPs.
- Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support
file/shmem-backed pages.
- userfaultfd updates from Axel Rasmussen
- zsmalloc cleanups from Alexey Romanov
- cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure
- Huang Ying adds enhancements to NUMA balancing memory tiering mode's
page promotion, with a new way of detecting hot pages.
- memcg updates from Shakeel Butt: charging optimizations and reduced
memory consumption.
- memcg cleanups from Kairui Song.
- memcg fixes and cleanups from Johannes Weiner.
- Vishal Moola provides more folio conversions
- Zhang Yi removed ll_rw_block() :(
- migration enhancements from Peter Xu
- migration error-path bugfixes from Huang Ying
- Aneesh Kumar added ability for a device driver to alter the memory
tiering promotion paths. For optimizations by PMEM drivers, DRM
drivers, etc.
- vma merging improvements from Jakub Matěn.
- NUMA hinting cleanups from David Hildenbrand.
- xu xin added aditional userspace visibility into KSM merging activity.
- THP & KSM code consolidation from Qi Zheng.
- more folio work from Matthew Wilcox.
- KASAN updates from Andrey Konovalov.
- DAMON cleanups from Kaixu Xia.
- DAMON work from SeongJae Park: fixes, cleanups.
- hugetlb sysfs cleanups from Muchun Song.
- Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
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Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any
negative reports (or any positive ones, come to that).
- Also the Maple Tree from Liam Howlett. An overlapping range-based
tree for vmas. It it apparently slightly more efficient in its own
right, but is mainly targeted at enabling work to reduce mmap_lock
contention.
Liam has identified a number of other tree users in the kernel which
could be beneficially onverted to mapletrees.
Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
at [1]. This has yet to be addressed due to Liam's unfortunately
timed vacation. He is now back and we'll get this fixed up.
- Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
clang-generated instrumentation to detect used-unintialized bugs down
to the single bit level.
KMSAN keeps finding bugs. New ones, as well as the legacy ones.
- Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
memory into THPs.
- Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
support file/shmem-backed pages.
- userfaultfd updates from Axel Rasmussen
- zsmalloc cleanups from Alexey Romanov
- cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
memory-failure
- Huang Ying adds enhancements to NUMA balancing memory tiering mode's
page promotion, with a new way of detecting hot pages.
- memcg updates from Shakeel Butt: charging optimizations and reduced
memory consumption.
- memcg cleanups from Kairui Song.
- memcg fixes and cleanups from Johannes Weiner.
- Vishal Moola provides more folio conversions
- Zhang Yi removed ll_rw_block() :(
- migration enhancements from Peter Xu
- migration error-path bugfixes from Huang Ying
- Aneesh Kumar added ability for a device driver to alter the memory
tiering promotion paths. For optimizations by PMEM drivers, DRM
drivers, etc.
- vma merging improvements from Jakub Matěn.
- NUMA hinting cleanups from David Hildenbrand.
- xu xin added aditional userspace visibility into KSM merging
activity.
- THP & KSM code consolidation from Qi Zheng.
- more folio work from Matthew Wilcox.
- KASAN updates from Andrey Konovalov.
- DAMON cleanups from Kaixu Xia.
- DAMON work from SeongJae Park: fixes, cleanups.
- hugetlb sysfs cleanups from Muchun Song.
- Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]
* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
hugetlb: allocate vma lock for all sharable vmas
hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
hugetlb: fix vma lock handling during split vma and range unmapping
mglru: mm/vmscan.c: fix imprecise comments
mm/mglru: don't sync disk for each aging cycle
mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
mm: memcontrol: use do_memsw_account() in a few more places
mm: memcontrol: deprecate swapaccounting=0 mode
mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
mm/secretmem: remove reduntant return value
mm/hugetlb: add available_huge_pages() func
mm: remove unused inline functions from include/linux/mm_inline.h
selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
selftests/vm: add thp collapse shmem testing
selftests/vm: add thp collapse file and tmpfs testing
selftests/vm: modularize thp collapse memory operations
selftests/vm: dedup THP helpers
mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
mm/madvise: add file and shmem support to MADV_COLLAPSE
...
- Debuggability:
- Change most occurances of BUG_ON() to WARN_ON_ONCE()
- Reorganize & fix TASK_ state comparisons, turn it into a bitmap
- Update/fix misc scheduler debugging facilities
- Load-balancing & regular scheduling:
- Improve the behavior of the scheduler in presence of lot of
SCHED_IDLE tasks - in particular they should not impact other
scheduling classes.
- Optimize task load tracking, cleanups & fixes
- Clean up & simplify misc load-balancing code
- Freezer:
- Rewrite the core freezer to behave better wrt thawing and be simpler
in general, by replacing PF_FROZEN with TASK_FROZEN & fixing/adjusting
all the fallout.
- Deadline scheduler:
- Fix the DL capacity-aware code
- Factor out dl_task_is_earliest_deadline() & replenish_dl_new_period()
- Relax/optimize locking in task_non_contending()
- Cleanups:
- Factor out the update_current_exec_runtime() helper
- Various cleanups, simplifications
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"Debuggability:
- Change most occurances of BUG_ON() to WARN_ON_ONCE()
- Reorganize & fix TASK_ state comparisons, turn it into a bitmap
- Update/fix misc scheduler debugging facilities
Load-balancing & regular scheduling:
- Improve the behavior of the scheduler in presence of lot of
SCHED_IDLE tasks - in particular they should not impact other
scheduling classes.
- Optimize task load tracking, cleanups & fixes
- Clean up & simplify misc load-balancing code
Freezer:
- Rewrite the core freezer to behave better wrt thawing and be
simpler in general, by replacing PF_FROZEN with TASK_FROZEN &
fixing/adjusting all the fallout.
Deadline scheduler:
- Fix the DL capacity-aware code
- Factor out dl_task_is_earliest_deadline() &
replenish_dl_new_period()
- Relax/optimize locking in task_non_contending()
Cleanups:
- Factor out the update_current_exec_runtime() helper
- Various cleanups, simplifications"
* tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
sched: Fix more TASK_state comparisons
sched: Fix TASK_state comparisons
sched/fair: Move call to list_last_entry() in detach_tasks
sched/fair: Cleanup loop_max and loop_break
sched/fair: Make sure to try to detach at least one movable task
sched: Show PF_flag holes
freezer,sched: Rewrite core freezer logic
sched: Widen TAKS_state literals
sched/wait: Add wait_event_state()
sched/completion: Add wait_for_completion_state()
sched: Add TASK_ANY for wait_task_inactive()
sched: Change wait_task_inactive()s match_state
freezer,umh: Clean up freezer/initrd interaction
freezer: Have {,un}lock_system_sleep() save/restore flags
sched: Rename task_running() to task_on_cpu()
sched/fair: Cleanup for SIS_PROP
sched/fair: Default to false in test_idle_cores()
sched/fair: Remove useless check in select_idle_core()
sched/fair: Avoid double search on same cpu
sched/fair: Remove redundant check in select_idle_smt()
...
Recently I had a conversation where it was pointed out to me that
SIGKILL sent to a tracee stropped in PTRACE_EVENT_EXIT is quite
difficult for a tracer to handle.
Keeping SIGKILL working after the process has been killed is pain
from an implementation point of view.
So since the debuggers don't want this behavior let's see if we can
remove this wart for the userspace API
If a regression is detected it should only need to be the last change
that is the reverted. The other two are just general cleanups that
make the last patch simpler.
Eric W. Biederman (3):
signal: Ensure SIGNAL_GROUP_EXIT gets set in do_group_exit
signal: Guarantee that SIGNAL_GROUP_EXIT is set on process exit
signal: Drop signals received after a fatal signal has been processed
fs/coredump.c | 2 +-
include/linux/sched/signal.h | 1 +
kernel/exit.c | 20 +++++++++++++++++++-
kernel/fork.c | 2 ++
kernel/signal.c | 3 ++-
5 files changed, 25 insertions(+), 3 deletions(-)
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Merge tag 'signal-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ptrace update from Eric Biederman:
"ptrace: Stop supporting SIGKILL for PTRACE_EVENT_EXIT
Recently I had a conversation where it was pointed out to me that
SIGKILL sent to a tracee stropped in PTRACE_EVENT_EXIT is quite
difficult for a tracer to handle.
Keeping SIGKILL working after the process has been killed is pain from
an implementation point of view.
So since the debuggers don't want this behavior let's see if we can
remove this wart for the userspace API
If a regression is detected it should only need to be the last change
that is the reverted. The other two are just general cleanups that
make the last patch simpler"
* tag 'signal-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
signal: Drop signals received after a fatal signal has been processed
signal: Guarantee that SIGNAL_GROUP_EXIT is set on process exit
signal: Ensure SIGNAL_GROUP_EXIT gets set in do_group_exit
To further exploit spatial locality, the aging prefers to walk page tables
to search for young PTEs and promote hot pages. A kill switch will be
added in the next patch to disable this behavior. When disabled, the
aging relies on the rmap only.
NB: this behavior has nothing similar with the page table scanning in the
2.4 kernel [1], which searches page tables for old PTEs, adds cold pages
to swapcache and unmaps them.
To avoid confusion, the term "iteration" specifically means the traversal
of an entire mm_struct list; the term "walk" will be applied to page
tables and the rmap, as usual.
An mm_struct list is maintained for each memcg, and an mm_struct follows
its owner task to the new memcg when this task is migrated. Given an
lruvec, the aging iterates lruvec_memcg()->mm_list and calls
walk_page_range() with each mm_struct on this list to promote hot pages
before it increments max_seq.
When multiple page table walkers iterate the same list, each of them gets
a unique mm_struct; therefore they can run concurrently. Page table
walkers ignore any misplaced pages, e.g., if an mm_struct was migrated,
pages it left in the previous memcg will not be promoted when its current
memcg is under reclaim. Similarly, page table walkers will not promote
pages from nodes other than the one under reclaim.
This patch uses the following optimizations when walking page tables:
1. It tracks the usage of mm_struct's between context switches so that
page table walkers can skip processes that have been sleeping since
the last iteration.
2. It uses generational Bloom filters to record populated branches so
that page table walkers can reduce their search space based on the
query results, e.g., to skip page tables containing mostly holes or
misplaced pages.
3. It takes advantage of the accessed bit in non-leaf PMD entries when
CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG=y.
4. It does not zigzag between a PGD table and the same PMD table
spanning multiple VMAs. IOW, it finishes all the VMAs within the
range of the same PMD table before it returns to a PGD table. This
improves the cache performance for workloads that have large
numbers of tiny VMAs [2], especially when CONFIG_PGTABLE_LEVELS=5.
Server benchmark results:
Single workload:
fio (buffered I/O): no change
Single workload:
memcached (anon): +[8, 10]%
Ops/sec KB/sec
patch1-7: 1147696.57 44640.29
patch1-8: 1245274.91 48435.66
Configurations:
no change
Client benchmark results:
kswapd profiles:
patch1-7
48.16% lzo1x_1_do_compress (real work)
8.20% page_vma_mapped_walk (overhead)
7.06% _raw_spin_unlock_irq
2.92% ptep_clear_flush
2.53% __zram_bvec_write
2.11% do_raw_spin_lock
2.02% memmove
1.93% lru_gen_look_around
1.56% free_unref_page_list
1.40% memset
patch1-8
49.44% lzo1x_1_do_compress (real work)
6.19% page_vma_mapped_walk (overhead)
5.97% _raw_spin_unlock_irq
3.13% get_pfn_folio
2.85% ptep_clear_flush
2.42% __zram_bvec_write
2.08% do_raw_spin_lock
1.92% memmove
1.44% alloc_zspage
1.36% memset
Configurations:
no change
Thanks to the following developers for their efforts [3].
kernel test robot <lkp@intel.com>
[1] https://lwn.net/Articles/23732/
[2] https://llvm.org/docs/ScudoHardenedAllocator.html
[3] https://lore.kernel.org/r/202204160827.ekEARWQo-lkp@intel.com/
Link: https://lkml.kernel.org/r/20220918080010.2920238-9-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Acked-by: Brian Geffon <bgeffon@google.com>
Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org>
Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Acked-by: Steven Barrett <steven@liquorix.net>
Acked-by: Suleiman Souhlal <suleiman@google.com>
Tested-by: Daniel Byrne <djbyrne@mtu.edu>
Tested-by: Donald Carr <d@chaos-reins.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru>
Tested-by: Shuang Zhai <szhai2@cs.rochester.edu>
Tested-by: Sofia Trinh <sofia.trinh@edi.works>
Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Larabel <Michael@MichaelLarabel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Rewrite the core freezer to behave better wrt thawing and be simpler
in general.
By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensured frozen tasks stay frozen until thawed and don't randomly wake
up early, as is currently possible.
As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up
two PF_flags (yay!).
Specifically; the current scheme works a little like:
freezer_do_not_count();
schedule();
freezer_count();
And either the task is blocked, or it lands in try_to_freezer()
through freezer_count(). Now, when it is blocked, the freezer
considers it frozen and continues.
However, on thawing, once pm_freezing is cleared, freezer_count()
stops working, and any random/spurious wakeup will let a task run
before its time.
That is, thawing tries to thaw things in explicit order; kernel
threads and workqueues before doing bringing SMP back before userspace
etc.. However due to the above mentioned races it is entirely possible
for userspace tasks to thaw (by accident) before SMP is back.
This can be a fatal problem in asymmetric ISA architectures (eg ARMv9)
where the userspace task requires a special CPU to run.
As said; replace this with a special task state TASK_FROZEN and add
the following state transitions:
TASK_FREEZABLE -> TASK_FROZEN
__TASK_STOPPED -> TASK_FROZEN
__TASK_TRACED -> TASK_FROZEN
The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL
(IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state
is already required to deal with spurious wakeups and the freezer
causes one such when thawing the task (since the original state is
lost).
The special __TASK_{STOPPED,TRACED} states *can* be restored since
their canonical state is in ->jobctl.
With this, frozen tasks need an explicit TASK_FROZEN wakeup and are
free of undue (early / spurious) wakeups.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org
Track how many threads have not started exiting and when the last
thread starts exiting set SIGNAL_GROUP_EXIT.
This guarantees that SIGNAL_GROUP_EXIT will get set when a process
exits. In practice this achieves nothing as glibc's implementation of
_exit calls sys_group_exit then sys_exit. While glibc's implemenation
of pthread_exit calls exit (which cleansup and calls _exit) if it is
the last thread and sys_exit if it is the last thread.
This means the only way the kernel might observe a process that does
not set call exit_group is if the language runtime does not use glibc.
With more cleanups I hope to move the decrement of quick_threads
earlier.
Link: https://lkml.kernel.org/r/87bkukd4tc.fsf_-_@email.froward.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The function do_group_exit has an optimization that avoids taking
siglock and doing the work to find other threads in the signal group
and shutting them down.
It is very desirable for SIGNAL_GROUP_EXIT to always been set whenever
it is decided for the process to exit. That ensures only a single
place needs to be tested, and a single bit of state needs to be looked
at. This makes the optimization in do_group_exit counter productive.
Make the code and maintenance simpler by removing this unnecessary
option.
Link: https://lkml.kernel.org/r/87letod4v3.fsf_-_@email.froward.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
As Chris explains, the comment above exit_itimers() is not correct,
we can race with proc_timers_seq_ops. Change exit_itimers() to clear
signal->posix_timers with ->siglock held.
Cc: <stable@vger.kernel.org>
Reported-by: chris@accessvector.net
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This set of changes removes tracehook.h, moves modification of all of
the ptrace fields inside of siglock to remove races, adds a missing
permission check to ptrace.c
The removal of tracehook.h is quite significant as it has been a major
source of confusion in recent years. Much of that confusion was
around task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled
making the semantics clearer).
For people who don't know tracehook.h is a vestiage of an attempt to
implement uprobes like functionality that was never fully merged, and
was later superseeded by uprobes when uprobes was merged. For many
years now we have been removing what tracehook functionaly a little
bit at a time. To the point where now anything left in tracehook.h is
some weird strange thing that is difficult to understand.
Eric W. Biederman (15):
ptrace: Move ptrace_report_syscall into ptrace.h
ptrace/arm: Rename tracehook_report_syscall report_syscall
ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h
ptrace: Remove arch_syscall_{enter,exit}_tracehook
ptrace: Remove tracehook_signal_handler
task_work: Remove unnecessary include from posix_timers.h
task_work: Introduce task_work_pending
task_work: Call tracehook_notify_signal from get_signal on all architectures
task_work: Decouple TIF_NOTIFY_SIGNAL and task_work
signal: Move set_notify_signal and clear_notify_signal into sched/signal.h
resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume
resume_user_mode: Move to resume_user_mode.h
tracehook: Remove tracehook.h
ptrace: Move setting/clearing ptrace_message into ptrace_stop
ptrace: Return the signal to continue with from ptrace_stop
Jann Horn (1):
ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE
Yang Li (1):
ptrace: Remove duplicated include in ptrace.c
MAINTAINERS | 1 -
arch/Kconfig | 5 +-
arch/alpha/kernel/ptrace.c | 5 +-
arch/alpha/kernel/signal.c | 4 +-
arch/arc/kernel/ptrace.c | 5 +-
arch/arc/kernel/signal.c | 4 +-
arch/arm/kernel/ptrace.c | 12 +-
arch/arm/kernel/signal.c | 4 +-
arch/arm64/kernel/ptrace.c | 14 +--
arch/arm64/kernel/signal.c | 4 +-
arch/csky/kernel/ptrace.c | 5 +-
arch/csky/kernel/signal.c | 4 +-
arch/h8300/kernel/ptrace.c | 5 +-
arch/h8300/kernel/signal.c | 4 +-
arch/hexagon/kernel/process.c | 4 +-
arch/hexagon/kernel/signal.c | 1 -
arch/hexagon/kernel/traps.c | 6 +-
arch/ia64/kernel/process.c | 4 +-
arch/ia64/kernel/ptrace.c | 6 +-
arch/ia64/kernel/signal.c | 1 -
arch/m68k/kernel/ptrace.c | 5 +-
arch/m68k/kernel/signal.c | 4 +-
arch/microblaze/kernel/ptrace.c | 5 +-
arch/microblaze/kernel/signal.c | 4 +-
arch/mips/kernel/ptrace.c | 5 +-
arch/mips/kernel/signal.c | 4 +-
arch/nds32/include/asm/syscall.h | 2 +-
arch/nds32/kernel/ptrace.c | 5 +-
arch/nds32/kernel/signal.c | 4 +-
arch/nios2/kernel/ptrace.c | 5 +-
arch/nios2/kernel/signal.c | 4 +-
arch/openrisc/kernel/ptrace.c | 5 +-
arch/openrisc/kernel/signal.c | 4 +-
arch/parisc/kernel/ptrace.c | 7 +-
arch/parisc/kernel/signal.c | 4 +-
arch/powerpc/kernel/ptrace/ptrace.c | 8 +-
arch/powerpc/kernel/signal.c | 4 +-
arch/riscv/kernel/ptrace.c | 5 +-
arch/riscv/kernel/signal.c | 4 +-
arch/s390/include/asm/entry-common.h | 1 -
arch/s390/kernel/ptrace.c | 1 -
arch/s390/kernel/signal.c | 5 +-
arch/sh/kernel/ptrace_32.c | 5 +-
arch/sh/kernel/signal_32.c | 4 +-
arch/sparc/kernel/ptrace_32.c | 5 +-
arch/sparc/kernel/ptrace_64.c | 5 +-
arch/sparc/kernel/signal32.c | 1 -
arch/sparc/kernel/signal_32.c | 4 +-
arch/sparc/kernel/signal_64.c | 4 +-
arch/um/kernel/process.c | 4 +-
arch/um/kernel/ptrace.c | 5 +-
arch/x86/kernel/ptrace.c | 1 -
arch/x86/kernel/signal.c | 5 +-
arch/x86/mm/tlb.c | 1 +
arch/xtensa/kernel/ptrace.c | 5 +-
arch/xtensa/kernel/signal.c | 4 +-
block/blk-cgroup.c | 2 +-
fs/coredump.c | 1 -
fs/exec.c | 1 -
fs/io-wq.c | 6 +-
fs/io_uring.c | 11 +-
fs/proc/array.c | 1 -
fs/proc/base.c | 1 -
include/asm-generic/syscall.h | 2 +-
include/linux/entry-common.h | 47 +-------
include/linux/entry-kvm.h | 2 +-
include/linux/posix-timers.h | 1 -
include/linux/ptrace.h | 81 ++++++++++++-
include/linux/resume_user_mode.h | 64 ++++++++++
include/linux/sched/signal.h | 17 +++
include/linux/task_work.h | 5 +
include/linux/tracehook.h | 226 -----------------------------------
include/uapi/linux/ptrace.h | 2 +-
kernel/entry/common.c | 19 +--
kernel/entry/kvm.c | 9 +-
kernel/exit.c | 3 +-
kernel/livepatch/transition.c | 1 -
kernel/ptrace.c | 47 +++++---
kernel/seccomp.c | 1 -
kernel/signal.c | 62 +++++-----
kernel/task_work.c | 4 +-
kernel/time/posix-cpu-timers.c | 1 +
mm/memcontrol.c | 2 +-
security/apparmor/domain.c | 1 -
security/selinux/hooks.c | 1 -
85 files changed, 372 insertions(+), 495 deletions(-)
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Merge tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ptrace cleanups from Eric Biederman:
"This set of changes removes tracehook.h, moves modification of all of
the ptrace fields inside of siglock to remove races, adds a missing
permission check to ptrace.c
The removal of tracehook.h is quite significant as it has been a major
source of confusion in recent years. Much of that confusion was around
task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled making the
semantics clearer).
For people who don't know tracehook.h is a vestiage of an attempt to
implement uprobes like functionality that was never fully merged, and
was later superseeded by uprobes when uprobes was merged. For many
years now we have been removing what tracehook functionaly a little
bit at a time. To the point where anything left in tracehook.h was
some weird strange thing that was difficult to understand"
* tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
ptrace: Remove duplicated include in ptrace.c
ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE
ptrace: Return the signal to continue with from ptrace_stop
ptrace: Move setting/clearing ptrace_message into ptrace_stop
tracehook: Remove tracehook.h
resume_user_mode: Move to resume_user_mode.h
resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume
signal: Move set_notify_signal and clear_notify_signal into sched/signal.h
task_work: Decouple TIF_NOTIFY_SIGNAL and task_work
task_work: Call tracehook_notify_signal from get_signal on all architectures
task_work: Introduce task_work_pending
task_work: Remove unnecessary include from posix_timers.h
ptrace: Remove tracehook_signal_handler
ptrace: Remove arch_syscall_{enter,exit}_tracehook
ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h
ptrace/arm: Rename tracehook_report_syscall report_syscall
ptrace: Move ptrace_report_syscall into ptrace.h
coarse grained, hardware based, forward edge Control-Flow-Integrity mechanism
where any indirect CALL/JMP must target an ENDBR instruction or suffer #CP.
Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation is
limited to 2 instructions (and typically fewer) on branch targets not starting
with ENDBR. CET-IBT also limits speculation of the next sequential instruction
after the indirect CALL/JMP [1].
CET-IBT is fundamentally incompatible with retpolines, but provides, as
described above, speculation limits itself.
[1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html
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Merge tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 CET-IBT (Control-Flow-Integrity) support from Peter Zijlstra:
"Add support for Intel CET-IBT, available since Tigerlake (11th gen),
which is a coarse grained, hardware based, forward edge
Control-Flow-Integrity mechanism where any indirect CALL/JMP must
target an ENDBR instruction or suffer #CP.
Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation
is limited to 2 instructions (and typically fewer) on branch targets
not starting with ENDBR. CET-IBT also limits speculation of the next
sequential instruction after the indirect CALL/JMP [1].
CET-IBT is fundamentally incompatible with retpolines, but provides,
as described above, speculation limits itself"
[1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html
* tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
kvm/emulate: Fix SETcc emulation for ENDBR
x86/Kconfig: Only allow CONFIG_X86_KERNEL_IBT with ld.lld >= 14.0.0
x86/Kconfig: Only enable CONFIG_CC_HAS_IBT for clang >= 14.0.0
kbuild: Fixup the IBT kbuild changes
x86/Kconfig: Do not allow CONFIG_X86_X32_ABI=y with llvm-objcopy
x86: Remove toolchain check for X32 ABI capability
x86/alternative: Use .ibt_endbr_seal to seal indirect calls
objtool: Find unused ENDBR instructions
objtool: Validate IBT assumptions
objtool: Add IBT/ENDBR decoding
objtool: Read the NOENDBR annotation
x86: Annotate idtentry_df()
x86,objtool: Move the ASM_REACHABLE annotation to objtool.h
x86: Annotate call_on_stack()
objtool: Rework ASM_REACHABLE
x86: Mark __invalid_creds() __noreturn
exit: Mark do_group_exit() __noreturn
x86: Mark stop_this_cpu() __noreturn
objtool: Ignore extra-symbol code
objtool: Rename --duplicate to --lto
...
Core
----
- Introduce XDP multi-buffer support, allowing the use of XDP with
jumbo frame MTUs and combination with Rx coalescing offloads (LRO).
- Speed up netns dismantling (5x) and lower the memory cost a little.
Remove unnecessary per-netns sockets. Scope some lists to a netns.
Cut down RCU syncing. Use batch methods. Allow netdev registration
to complete out of order.
- Support distinguishing timestamp types (ingress vs egress) and
maintaining them across packet scrubbing points (e.g. redirect).
- Continue the work of annotating packet drop reasons throughout
the stack.
- Switch netdev error counters from an atomic to dynamically
allocated per-CPU counters.
- Rework a few preempt_disable(), local_irq_save() and busy waiting
sections problematic on PREEMPT_RT.
- Extend the ref_tracker to allow catching use-after-free bugs.
BPF
---
- Introduce "packing allocator" for BPF JIT images. JITed code is
marked read only, and used to be allocated at page granularity.
Custom allocator allows for more efficient memory use, lower
iTLB pressure and prevents identity mapping huge pages from
getting split.
- Make use of BTF type annotations (e.g. __user, __percpu) to enforce
the correct probe read access method, add appropriate helpers.
- Convert the BPF preload to use light skeleton and drop
the user-mode-driver dependency.
- Allow XDP BPF_PROG_RUN test infra to send real packets, enabling
its use as a packet generator.
- Allow local storage memory to be allocated with GFP_KERNEL if called
from a hook allowed to sleep.
- Introduce fprobe (multi kprobe) to speed up mass attachment (arch
bits to come later).
- Add unstable conntrack lookup helpers for BPF by using the BPF
kfunc infra.
- Allow cgroup BPF progs to return custom errors to user space.
- Add support for AF_UNIX iterator batching.
- Allow iterator programs to use sleepable helpers.
- Support JIT of add, and, or, xor and xchg atomic ops on arm64.
- Add BTFGen support to bpftool which allows to use CO-RE in kernels
without BTF info.
- Large number of libbpf API improvements, cleanups and deprecations.
Protocols
---------
- Micro-optimize UDPv6 Tx, gaining up to 5% in test on dummy netdev.
- Adjust TSO packet sizes based on min_rtt, allowing very low latency
links (data centers) to always send full-sized TSO super-frames.
- Make IPv6 flow label changes (AKA hash rethink) more configurable,
via sysctl and setsockopt. Distinguish between server and client
behavior.
- VxLAN support to "collect metadata" devices to terminate only
configured VNIs. This is similar to VLAN filtering in the bridge.
- Support inserting IPv6 IOAM information to a fraction of frames.
- Add protocol attribute to IP addresses to allow identifying where
given address comes from (kernel-generated, DHCP etc.)
- Support setting socket and IPv6 options via cmsg on ping6 sockets.
- Reject mis-use of ECN bits in IP headers as part of DSCP/TOS.
Define dscp_t and stop taking ECN bits into account in fib-rules.
- Add support for locked bridge ports (for 802.1X).
- tun: support NAPI for packets received from batched XDP buffs,
doubling the performance in some scenarios.
- IPv6 extension header handling in Open vSwitch.
- Support IPv6 control message load balancing in bonding, prevent
neighbor solicitation and advertisement from using the wrong port.
Support NS/NA monitor selection similar to existing ARP monitor.
- SMC
- improve performance with TCP_CORK and sendfile()
- support auto-corking
- support TCP_NODELAY
- MCTP (Management Component Transport Protocol)
- add user space tag control interface
- I2C binding driver (as specified by DMTF DSP0237)
- Multi-BSSID beacon handling in AP mode for WiFi.
- Bluetooth:
- handle MSFT Monitor Device Event
- add MGMT Adv Monitor Device Found/Lost events
- Multi-Path TCP:
- add support for the SO_SNDTIMEO socket option
- lots of selftest cleanups and improvements
- Increase the max PDU size in CAN ISOTP to 64 kB.
Driver API
----------
- Add HW counters for SW netdevs, a mechanism for devices which
offload packet forwarding to report packet statistics back to
software interfaces such as tunnels.
- Select the default NIC queue count as a fraction of number of
physical CPU cores, instead of hard-coding to 8.
- Expose devlink instance locks to drivers. Allow device layer of
drivers to use that lock directly instead of creating their own
which always runs into ordering issues in devlink callbacks.
- Add header/data split indication to guide user space enabling
of TCP zero-copy Rx.
- Allow configuring completion queue event size.
- Refactor page_pool to enable fragmenting after allocation.
- Add allocation and page reuse statistics to page_pool.
- Improve Multiple Spanning Trees support in the bridge to allow
reuse of topologies across VLANs, saving HW resources in switches.
- DSA (Distributed Switch Architecture):
- replay and offload of host VLAN entries
- offload of static and local FDB entries on LAG interfaces
- FDB isolation and unicast filtering
New hardware / drivers
----------------------
- Ethernet:
- LAN937x T1 PHYs
- Davicom DM9051 SPI NIC driver
- Realtek RTL8367S, RTL8367RB-VB switch and MDIO
- Microchip ksz8563 switches
- Netronome NFP3800 SmartNICs
- Fungible SmartNICs
- MediaTek MT8195 switches
- WiFi:
- mt76: MediaTek mt7916
- mt76: MediaTek mt7921u USB adapters
- brcmfmac: Broadcom BCM43454/6
- Mobile:
- iosm: Intel M.2 7360 WWAN card
Drivers
-------
- Convert many drivers to the new phylink API built for split PCS
designs but also simplifying other cases.
- Intel Ethernet NICs:
- add TTY for GNSS module for E810T device
- improve AF_XDP performance
- GTP-C and GTP-U filter offload
- QinQ VLAN support
- Mellanox Ethernet NICs (mlx5):
- support xdp->data_meta
- multi-buffer XDP
- offload tc push_eth and pop_eth actions
- Netronome Ethernet NICs (nfp):
- flow-independent tc action hardware offload (police / meter)
- AF_XDP
- Other Ethernet NICs:
- at803x: fiber and SFP support
- xgmac: mdio: preamble suppression and custom MDC frequencies
- r8169: enable ASPM L1.2 if system vendor flags it as safe
- macb/gem: ZynqMP SGMII
- hns3: add TX push mode
- dpaa2-eth: software TSO
- lan743x: multi-queue, mdio, SGMII, PTP
- axienet: NAPI and GRO support
- Mellanox Ethernet switches (mlxsw):
- source and dest IP address rewrites
- RJ45 ports
- Marvell Ethernet switches (prestera):
- basic routing offload
- multi-chain TC ACL offload
- NXP embedded Ethernet switches (ocelot & felix):
- PTP over UDP with the ocelot-8021q DSA tagging protocol
- basic QoS classification on Felix DSA switch using dcbnl
- port mirroring for ocelot switches
- Microchip high-speed industrial Ethernet (sparx5):
- offloading of bridge port flooding flags
- PTP Hardware Clock
- Other embedded switches:
- lan966x: PTP Hardward Clock
- qca8k: mdio read/write operations via crafted Ethernet packets
- Qualcomm 802.11ax WiFi (ath11k):
- add LDPC FEC type and 802.11ax High Efficiency data in radiotap
- enable RX PPDU stats in monitor co-exist mode
- Intel WiFi (iwlwifi):
- UHB TAS enablement via BIOS
- band disablement via BIOS
- channel switch offload
- 32 Rx AMPDU sessions in newer devices
- MediaTek WiFi (mt76):
- background radar detection
- thermal management improvements on mt7915
- SAR support for more mt76 platforms
- MBSSID and 6 GHz band on mt7915
- RealTek WiFi:
- rtw89: AP mode
- rtw89: 160 MHz channels and 6 GHz band
- rtw89: hardware scan
- Bluetooth:
- mt7921s: wake on Bluetooth, SCO over I2S, wide-band-speed (WBS)
- Microchip CAN (mcp251xfd):
- multiple RX-FIFOs and runtime configurable RX/TX rings
- internal PLL, runtime PM handling simplification
- improve chip detection and error handling after wakeup
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
"The sprinkling of SPI drivers is because we added a new one and Mark
sent us a SPI driver interface conversion pull request.
Core
----
- Introduce XDP multi-buffer support, allowing the use of XDP with
jumbo frame MTUs and combination with Rx coalescing offloads (LRO).
- Speed up netns dismantling (5x) and lower the memory cost a little.
Remove unnecessary per-netns sockets. Scope some lists to a netns.
Cut down RCU syncing. Use batch methods. Allow netdev registration
to complete out of order.
- Support distinguishing timestamp types (ingress vs egress) and
maintaining them across packet scrubbing points (e.g. redirect).
- Continue the work of annotating packet drop reasons throughout the
stack.
- Switch netdev error counters from an atomic to dynamically
allocated per-CPU counters.
- Rework a few preempt_disable(), local_irq_save() and busy waiting
sections problematic on PREEMPT_RT.
- Extend the ref_tracker to allow catching use-after-free bugs.
BPF
---
- Introduce "packing allocator" for BPF JIT images. JITed code is
marked read only, and used to be allocated at page granularity.
Custom allocator allows for more efficient memory use, lower iTLB
pressure and prevents identity mapping huge pages from getting
split.
- Make use of BTF type annotations (e.g. __user, __percpu) to enforce
the correct probe read access method, add appropriate helpers.
- Convert the BPF preload to use light skeleton and drop the
user-mode-driver dependency.
- Allow XDP BPF_PROG_RUN test infra to send real packets, enabling
its use as a packet generator.
- Allow local storage memory to be allocated with GFP_KERNEL if
called from a hook allowed to sleep.
- Introduce fprobe (multi kprobe) to speed up mass attachment (arch
bits to come later).
- Add unstable conntrack lookup helpers for BPF by using the BPF
kfunc infra.
- Allow cgroup BPF progs to return custom errors to user space.
- Add support for AF_UNIX iterator batching.
- Allow iterator programs to use sleepable helpers.
- Support JIT of add, and, or, xor and xchg atomic ops on arm64.
- Add BTFGen support to bpftool which allows to use CO-RE in kernels
without BTF info.
- Large number of libbpf API improvements, cleanups and deprecations.
Protocols
---------
- Micro-optimize UDPv6 Tx, gaining up to 5% in test on dummy netdev.
- Adjust TSO packet sizes based on min_rtt, allowing very low latency
links (data centers) to always send full-sized TSO super-frames.
- Make IPv6 flow label changes (AKA hash rethink) more configurable,
via sysctl and setsockopt. Distinguish between server and client
behavior.
- VxLAN support to "collect metadata" devices to terminate only
configured VNIs. This is similar to VLAN filtering in the bridge.
- Support inserting IPv6 IOAM information to a fraction of frames.
- Add protocol attribute to IP addresses to allow identifying where
given address comes from (kernel-generated, DHCP etc.)
- Support setting socket and IPv6 options via cmsg on ping6 sockets.
- Reject mis-use of ECN bits in IP headers as part of DSCP/TOS.
Define dscp_t and stop taking ECN bits into account in fib-rules.
- Add support for locked bridge ports (for 802.1X).
- tun: support NAPI for packets received from batched XDP buffs,
doubling the performance in some scenarios.
- IPv6 extension header handling in Open vSwitch.
- Support IPv6 control message load balancing in bonding, prevent
neighbor solicitation and advertisement from using the wrong port.
Support NS/NA monitor selection similar to existing ARP monitor.
- SMC
- improve performance with TCP_CORK and sendfile()
- support auto-corking
- support TCP_NODELAY
- MCTP (Management Component Transport Protocol)
- add user space tag control interface
- I2C binding driver (as specified by DMTF DSP0237)
- Multi-BSSID beacon handling in AP mode for WiFi.
- Bluetooth:
- handle MSFT Monitor Device Event
- add MGMT Adv Monitor Device Found/Lost events
- Multi-Path TCP:
- add support for the SO_SNDTIMEO socket option
- lots of selftest cleanups and improvements
- Increase the max PDU size in CAN ISOTP to 64 kB.
Driver API
----------
- Add HW counters for SW netdevs, a mechanism for devices which
offload packet forwarding to report packet statistics back to
software interfaces such as tunnels.
- Select the default NIC queue count as a fraction of number of
physical CPU cores, instead of hard-coding to 8.
- Expose devlink instance locks to drivers. Allow device layer of
drivers to use that lock directly instead of creating their own
which always runs into ordering issues in devlink callbacks.
- Add header/data split indication to guide user space enabling of
TCP zero-copy Rx.
- Allow configuring completion queue event size.
- Refactor page_pool to enable fragmenting after allocation.
- Add allocation and page reuse statistics to page_pool.
- Improve Multiple Spanning Trees support in the bridge to allow
reuse of topologies across VLANs, saving HW resources in switches.
- DSA (Distributed Switch Architecture):
- replay and offload of host VLAN entries
- offload of static and local FDB entries on LAG interfaces
- FDB isolation and unicast filtering
New hardware / drivers
----------------------
- Ethernet:
- LAN937x T1 PHYs
- Davicom DM9051 SPI NIC driver
- Realtek RTL8367S, RTL8367RB-VB switch and MDIO
- Microchip ksz8563 switches
- Netronome NFP3800 SmartNICs
- Fungible SmartNICs
- MediaTek MT8195 switches
- WiFi:
- mt76: MediaTek mt7916
- mt76: MediaTek mt7921u USB adapters
- brcmfmac: Broadcom BCM43454/6
- Mobile:
- iosm: Intel M.2 7360 WWAN card
Drivers
-------
- Convert many drivers to the new phylink API built for split PCS
designs but also simplifying other cases.
- Intel Ethernet NICs:
- add TTY for GNSS module for E810T device
- improve AF_XDP performance
- GTP-C and GTP-U filter offload
- QinQ VLAN support
- Mellanox Ethernet NICs (mlx5):
- support xdp->data_meta
- multi-buffer XDP
- offload tc push_eth and pop_eth actions
- Netronome Ethernet NICs (nfp):
- flow-independent tc action hardware offload (police / meter)
- AF_XDP
- Other Ethernet NICs:
- at803x: fiber and SFP support
- xgmac: mdio: preamble suppression and custom MDC frequencies
- r8169: enable ASPM L1.2 if system vendor flags it as safe
- macb/gem: ZynqMP SGMII
- hns3: add TX push mode
- dpaa2-eth: software TSO
- lan743x: multi-queue, mdio, SGMII, PTP
- axienet: NAPI and GRO support
- Mellanox Ethernet switches (mlxsw):
- source and dest IP address rewrites
- RJ45 ports
- Marvell Ethernet switches (prestera):
- basic routing offload
- multi-chain TC ACL offload
- NXP embedded Ethernet switches (ocelot & felix):
- PTP over UDP with the ocelot-8021q DSA tagging protocol
- basic QoS classification on Felix DSA switch using dcbnl
- port mirroring for ocelot switches
- Microchip high-speed industrial Ethernet (sparx5):
- offloading of bridge port flooding flags
- PTP Hardware Clock
- Other embedded switches:
- lan966x: PTP Hardward Clock
- qca8k: mdio read/write operations via crafted Ethernet packets
- Qualcomm 802.11ax WiFi (ath11k):
- add LDPC FEC type and 802.11ax High Efficiency data in radiotap
- enable RX PPDU stats in monitor co-exist mode
- Intel WiFi (iwlwifi):
- UHB TAS enablement via BIOS
- band disablement via BIOS
- channel switch offload
- 32 Rx AMPDU sessions in newer devices
- MediaTek WiFi (mt76):
- background radar detection
- thermal management improvements on mt7915
- SAR support for more mt76 platforms
- MBSSID and 6 GHz band on mt7915
- RealTek WiFi:
- rtw89: AP mode
- rtw89: 160 MHz channels and 6 GHz band
- rtw89: hardware scan
- Bluetooth:
- mt7921s: wake on Bluetooth, SCO over I2S, wide-band-speed (WBS)
- Microchip CAN (mcp251xfd):
- multiple RX-FIFOs and runtime configurable RX/TX rings
- internal PLL, runtime PM handling simplification
- improve chip detection and error handling after wakeup"
* tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2521 commits)
llc: fix netdevice reference leaks in llc_ui_bind()
drivers: ethernet: cpsw: fix panic when interrupt coaleceing is set via ethtool
ice: don't allow to run ice_send_event_to_aux() in atomic ctx
ice: fix 'scheduling while atomic' on aux critical err interrupt
net/sched: fix incorrect vlan_push_eth dest field
net: bridge: mst: Restrict info size queries to bridge ports
net: marvell: prestera: add missing destroy_workqueue() in prestera_module_init()
drivers: net: xgene: Fix regression in CRC stripping
net: geneve: add missing netlink policy and size for IFLA_GENEVE_INNER_PROTO_INHERIT
net: dsa: fix missing host-filtered multicast addresses
net/mlx5e: Fix build warning, detected write beyond size of field
iwlwifi: mvm: Don't fail if PPAG isn't supported
selftests/bpf: Fix kprobe_multi test.
Revert "rethook: x86: Add rethook x86 implementation"
Revert "arm64: rethook: Add arm64 rethook implementation"
Revert "powerpc: Add rethook support"
Revert "ARM: rethook: Add rethook arm implementation"
netdevice: add missing dm_private kdoc
net: bridge: mst: prevent NULL deref in br_mst_info_size()
selftests: forwarding: Use same VRF for port and VLAN upper
...
There are three sets of updates for 5.18 in the asm-generic tree:
- The set_fs()/get_fs() infrastructure gets removed for good. This
was already gone from all major architectures, but now we can
finally remove it everywhere, which loses some particularly
tricky and error-prone code.
There is a small merge conflict against a parisc cleanup, the
solution is to use their new version.
- The nds32 architecture ends its tenure in the Linux kernel. The
hardware is still used and the code is in reasonable shape, but
the mainline port is not actively maintained any more, as all
remaining users are thought to run vendor kernels that would never
be updated to a future release.
There are some obvious conflicts against changes to the removed
files.
- A series from Masahiro Yamada cleans up some of the uapi header
files to pass the compile-time checks.
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Merge tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull asm-generic updates from Arnd Bergmann:
"There are three sets of updates for 5.18 in the asm-generic tree:
- The set_fs()/get_fs() infrastructure gets removed for good.
This was already gone from all major architectures, but now we can
finally remove it everywhere, which loses some particularly tricky
and error-prone code. There is a small merge conflict against a
parisc cleanup, the solution is to use their new version.
- The nds32 architecture ends its tenure in the Linux kernel.
The hardware is still used and the code is in reasonable shape, but
the mainline port is not actively maintained any more, as all
remaining users are thought to run vendor kernels that would never
be updated to a future release.
- A series from Masahiro Yamada cleans up some of the uapi header
files to pass the compile-time checks"
* tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (27 commits)
nds32: Remove the architecture
uaccess: remove CONFIG_SET_FS
ia64: remove CONFIG_SET_FS support
sh: remove CONFIG_SET_FS support
sparc64: remove CONFIG_SET_FS support
lib/test_lockup: fix kernel pointer check for separate address spaces
uaccess: generalize access_ok()
uaccess: fix type mismatch warnings from access_ok()
arm64: simplify access_ok()
m68k: fix access_ok for coldfire
MIPS: use simpler access_ok()
MIPS: Handle address errors for accesses above CPU max virtual user address
uaccess: add generic __{get,put}_kernel_nofault
nios2: drop access_ok() check from __put_user()
x86: use more conventional access_ok() definition
x86: remove __range_not_ok()
sparc64: add __{get,put}_kernel_nofault()
nds32: fix access_ok() checks in get/put_user
uaccess: fix nios2 and microblaze get_user_8()
sparc64: fix building assembly files
...
Add a return hook framework which hooks the function return. Most of the
logic came from the kretprobe, but this is independent from kretprobe.
Note that this is expected to be used with other function entry hooking
feature, like ftrace, fprobe, adn kprobes. Eventually this will replace
the kretprobe (e.g. kprobe + rethook = kretprobe), but at this moment,
this is just an additional hook.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/164735285066.1084943.9259661137330166643.stgit@devnote2
Now that all of the definitions have moved out of tracehook.h into
ptrace.h, sched/signal.h, resume_user_mode.h there is nothing left in
tracehook.h so remove it.
Update the few files that were depending upon tracehook.h to bring in
definitions to use the headers they need directly.
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20220309162454.123006-13-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
There are no remaining callers of set_fs(), so CONFIG_SET_FS
can be removed globally, along with the thread_info field and
any references to it.
This turns access_ok() into a cheaper check against TASK_SIZE_MAX.
As CONFIG_SET_FS is now gone, drop all remaining references to
set_fs()/get_fs(), mm_segment_t, user_addr_max() and uaccess_kernel().
Acked-by: Sam Ravnborg <sam@ravnborg.org> # for sparc32 changes
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Tested-by: Sergey Matyukevich <sergey.matyukevich@synopsys.com> # for arc changes
Acked-by: Stafford Horne <shorne@gmail.com> # [openrisc, asm-generic]
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
There is no need to perform the stack accounting of the outgoing task in
its final schedule() invocation which happens with preemption disabled.
The task is leaving, the resources will be freed and the accounting can
happen in do_exit() before the actual schedule invocation which
frees the stack memory.
Move the accounting of the stack memory from release_task_stack() to
exit_task_stack_account() which then can be invoked from do_exit().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20220217102406.3697941-7-bigeasy@linutronix.de
blk_needs_flush_plug fails to account for the cb_list, which needs
flushing as well. Remove it and just check if there is a plug instead
of poking into the internals of the plug structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220127070549.1377856-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The function wait_task_zombie is defined to always returns the process not
thread exit status. Unfortunately when process group exit support
was added to wait_task_zombie the WNOWAIT case was overlooked.
Usually tsk->exit_code and tsk->signal->group_exit_code will be in sync
so fixing this is bug probably has no effect in practice. But fix
it anyway so that people aren't scratching their heads about why
the two code paths are different.
History-Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Fixes: 2c66151cbc2c ("[PATCH] sys_exit() threading improvements, BK-curr")
Link: https://lkml.kernel.org/r/20220103213312.9144-3-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The comment about coredumps not reaching do_group_exit and the
corresponding BUG_ON are bogus.
What happens and has happened for years is that get_signal calls
do_coredump (which sets SIGNAL_GROUP_EXIT and group_exit_code) and
then do_group_exit passing the signal number. Then do_group_exit
ignores the exit_code it is passed and uses signal->group_exit_code
from the coredump.
The comment and BUG_ON were correct when they were added during the
2.5 development cycle, but became obsolete and incorrect when
get_signal was changed to fall through to do_group_exit after
do_coredump in 2.6.10-rc2.
So remove the stale comment and BUG_ON
Fixes: 63bd6144f191 ("[PATCH] Invalid BUG_ONs in signal.c")
History-Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Link: https://lkml.kernel.org/r/20220103213312.9144-2-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
When I say remove I mean remove. All profile_task_exit and
profile_munmap do is call a blocking notifier chain. The helpers
profile_task_register and profile_task_unregister are not called
anywhere in the tree. Which means this is all dead code.
So remove the dead code and make it easier to read do_exit.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lkml.kernel.org/r/20220103213312.9144-1-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This helper is misleading. It tests for an ongoing exec as well as
the process having received a fatal signal.
Sometimes it is appropriate to treat an on-going exec differently than
a process that is shutting down due to a fatal signal. In particular
taking the fast path out of exit_signals instead of retargeting
signals is not appropriate during exec, and not changing the the exit
code in do_group_exit during exec.
Removing the helper makes it more obvious what is going on as both
cases must be coded for explicitly.
While removing the helper fix the two cases where I have observed
using signal_group_exit resulted in the wrong result.
In exit_signals only test for SIGNAL_GROUP_EXIT so that signals are
retargetted during an exec.
In do_group_exit use 0 as the exit code during an exec as de_thread
does not set group_exit_code. As best as I can determine
group_exit_code has been is set to 0 most of the time during
de_thread. During a thread group stop group_exit_code is set to the
stop signal and when the thread group receives SIGCONT group_exit_code
is reset to 0.
Link: https://lkml.kernel.org/r/20211213225350.27481-8-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The only remaining user of group_exit_task is exec. Rename the field
so that it is clear which part of the code uses it.
Update the comment above the definition of group_exec_task to document
how it is currently used.
Link: https://lkml.kernel.org/r/20211213225350.27481-7-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
With kernel threads on architectures that still have set_fs/get_fs
running as KERNEL_DS moving force_uaccess_begin does not appear safe.
Calling force_uaccess_begin is a noop on anything people care about.
Update the comment to explain why this code while looking like an
obvious candidate for moving to make_task_dead probably needs to
remain in do_exit until set_fs/get_fs are entirely removed from the
kernel.
Fixes: 05ea0424f0 ("exit: Move oops specific logic from do_exit into make_task_dead")
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/YdUxGKRcSiDy8jGg@zeniv-ca.linux.org.uk
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Change the task state to EXIT_DEAD and take an extra rcu_refernce
to guarantee the task will not be reaped and that it will not be
freed.
Link: https://lkml.kernel.org/r/YdUzjrLAlRiNLQp2@zeniv-ca.linux.org.uk
Pointed-out-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: 7f80a2fd7d ("exit: Stop poorly open coding do_task_dead in make_task_dead")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Update complete_and_exit to call kthread_exit instead of do_exit.
Change the name to reflect this change in functionality. All of the
users of complete_and_exit are causing the current kthread to exit so
this change makes it clear what is happening.
Move the implementation of kthread_complete_and_exit from
kernel/exit.c to to kernel/kthread.c. As this function is kthread
specific it makes most sense to live with the kthread functions.
There are no functional change.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Now that there are no more modular uses of do_exit remove the EXPORT_SYMBOL.
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
When the kernel detects it is oops or otherwise force killing a task
while it exits the code poorly attempts to permanently stop the task
from scheduling.
I say poorly because it is possible for a task in TASK_UINTERRUPTIBLE
to be woken up.
As it makes no sense for the task to continue call do_task_dead
instead which actually does the work and permanently removes the task
from the scheduler. Guaranteeing the task will never be woken
up again.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The beginning of do_exit has become cluttered and difficult to read as
it is filled with checks to handle things that can only happen when
the kernel is operating improperly.
Now that we have a dedicated function for cleaning up a task when the
kernel is operating improperly move the checks there.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
There are two big uses of do_exit. The first is it's design use to be
the guts of the exit(2) system call. The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.
Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure. In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.
Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.
As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Pull per signal_struct coredumps from Eric Biederman:
"Current coredumps are mixed up with the exit code, the signal handling
code, and the ptrace code making coredumps much more complicated than
necessary and difficult to follow.
This series of changes starts with ptrace_stop and cleans it up,
making it easier to follow what is happening in ptrace_stop. Then
cleans up the exec interactions with coredumps. Then cleans up the
coredump interactions with exit. Finally the coredump interactions
with the signal handling code is cleaned up.
The first and last changes are bug fixes for minor bugs.
I believe the fact that vfork followed by execve can kill the process
the called vfork if exec fails is sufficient justification to change
the userspace visible behavior.
In previous discussions some of these changes were organized
differently and individually appeared to make the code base worse. As
currently written I believe they all stand on their own as cleanups
and bug fixes.
Which means that even if the worst should happen and the last change
needs to be reverted for some unimaginable reason, the code base will
still be improved.
If the worst does not happen there are a more cleanups that can be
made. Signals that generate coredumps can easily become eligible for
short circuit delivery in complete_signal. The entire rendezvous for
generating a coredump can move into get_signal. The function
force_sig_info_to_task be written in a way that does not modify the
signal handling state of the target task (because coredumps are
eligible for short circuit delivery). Many of these future cleanups
can be done another way but nothing so cleanly as if coredumps become
per signal_struct"
* 'per_signal_struct_coredumps-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
coredump: Limit coredumps to a single thread group
coredump: Don't perform any cleanups before dumping core
exit: Factor coredump_exit_mm out of exit_mm
exec: Check for a pending fatal signal instead of core_state
ptrace: Remove the unnecessary arguments from arch_ptrace_stop
signal: Remove the bogus sigkill_pending in ptrace_stop
- Revert the printk format based wchan() symbol resolution as it can leak
the raw value in case that the symbol is not resolvable.
- Make wchan() more robust and work with all kind of unwinders by
enforcing that the task stays blocked while unwinding is in progress.
- Prevent sched_fork() from accessing an invalid sched_task_group
- Improve asymmetric packing logic
- Extend scheduler statistics to RT and DL scheduling classes and add
statistics for bandwith burst to the SCHED_FAIR class.
- Properly account SCHED_IDLE entities
- Prevent a potential deadlock when initial priority is assigned to a
newly created kthread. A recent change to plug a race between cpuset and
__sched_setscheduler() introduced a new lock dependency which is now
triggered. Break the lock dependency chain by moving the priority
assignment to the thread function.
- Fix the idle time reporting in /proc/uptime for NOHZ enabled systems.
- Improve idle balancing in general and especially for NOHZ enabled
systems.
- Provide proper interfaces for live patching so it does not have to
fiddle with scheduler internals.
- Add cluster aware scheduling support.
- A small set of tweaks for RT (irqwork, wait_task_inactive(), various
scheduler options and delaying mmdrop)
- The usual small tweaks and improvements all over the place
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Merge tag 'sched-core-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Thomas Gleixner:
- Revert the printk format based wchan() symbol resolution as it can
leak the raw value in case that the symbol is not resolvable.
- Make wchan() more robust and work with all kind of unwinders by
enforcing that the task stays blocked while unwinding is in progress.
- Prevent sched_fork() from accessing an invalid sched_task_group
- Improve asymmetric packing logic
- Extend scheduler statistics to RT and DL scheduling classes and add
statistics for bandwith burst to the SCHED_FAIR class.
- Properly account SCHED_IDLE entities
- Prevent a potential deadlock when initial priority is assigned to a
newly created kthread. A recent change to plug a race between cpuset
and __sched_setscheduler() introduced a new lock dependency which is
now triggered. Break the lock dependency chain by moving the priority
assignment to the thread function.
- Fix the idle time reporting in /proc/uptime for NOHZ enabled systems.
- Improve idle balancing in general and especially for NOHZ enabled
systems.
- Provide proper interfaces for live patching so it does not have to
fiddle with scheduler internals.
- Add cluster aware scheduling support.
- A small set of tweaks for RT (irqwork, wait_task_inactive(), various
scheduler options and delaying mmdrop)
- The usual small tweaks and improvements all over the place
* tag 'sched-core-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (69 commits)
sched/fair: Cleanup newidle_balance
sched/fair: Remove sysctl_sched_migration_cost condition
sched/fair: Wait before decaying max_newidle_lb_cost
sched/fair: Skip update_blocked_averages if we are defering load balance
sched/fair: Account update_blocked_averages in newidle_balance cost
x86: Fix __get_wchan() for !STACKTRACE
sched,x86: Fix L2 cache mask
sched/core: Remove rq_relock()
sched: Improve wake_up_all_idle_cpus() take #2
irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT
irq_work: Handle some irq_work in a per-CPU thread on PREEMPT_RT
irq_work: Allow irq_work_sync() to sleep if irq_work() no IRQ support.
sched/rt: Annotate the RT balancing logic irqwork as IRQ_WORK_HARD_IRQ
sched: Add cluster scheduler level for x86
sched: Add cluster scheduler level in core and related Kconfig for ARM64
topology: Represent clusters of CPUs within a die
sched: Disable -Wunused-but-set-variable
sched: Add wrapper for get_wchan() to keep task blocked
x86: Fix get_wchan() to support the ORC unwinder
proc: Use task_is_running() for wchan in /proc/$pid/stat
...
Various files have acquired spurious includes of <linux/blkdev.h> over
time. Remove them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Today when a signal is delivered with a handler of SIG_DFL whose
default behavior is to generate a core dump not only that process but
every process that shares the mm is killed.
In the case of vfork this looks like a real world problem. Consider
the following well defined sequence.
if (vfork() == 0) {
execve(...);
_exit(EXIT_FAILURE);
}
If a signal that generates a core dump is received after vfork but
before the execve changes the mm the process that called vfork will
also be killed (as the mm is shared).
Similarly if the execve fails after the point of no return the kernel
delivers SIGSEGV which will kill both the exec'ing process and because
the mm is shared the process that called vfork as well.
As far as I can tell this behavior is a violation of people's
reasonable expectations, POSIX, and is unnecessarily fragile when the
system is low on memory.
Solve this by making a userspace visible change to only kill a single
process/thread group. This is possible because Jann Horn recently
modified[1] the coredump code so that the mm can safely be modified
while the coredump is happening. With LinuxThreads long gone I don't
expect anyone to have a notice this behavior change in practice.
To accomplish this move the core_state pointer from mm_struct to
signal_struct, which allows different thread groups to coredump
simultatenously.
In zap_threads remove the work to kill anything except for the current
thread group.
v2: Remove core_state from the VM_BUG_ON_MM print to fix
compile failure when CONFIG_DEBUG_VM is enabled.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
[1] a07279c9a8 ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot")
Fixes: d89f3847def4 ("[PATCH] thread-aware coredumps, 2.5.43-C3")
History-tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Link: https://lkml.kernel.org/r/87y27mvnke.fsf@disp2133
Link: https://lkml.kernel.org/r/20211007144701.67592574@canb.auug.org.au
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Rename coredump_exit_mm to coredump_task_exit and call it from do_exit
before PTRACE_EVENT_EXIT, and before any cleanup work for a task
happens. This ensures that an accurate copy of the process can be
captured in the coredump as no cleanup for the process happens before
the coredump completes. This also ensures that PTRACE_EVENT_EXIT
will not be visited by any thread until the coredump is complete.
Add a new flag PF_POSTCOREDUMP so that tasks that have passed through
coredump_task_exit can be recognized and ignored in zap_process.
Now that all of the coredumping happens before exit_mm remove code to
test for a coredump in progress from mm_release.
Replace "may_ptrace_stop()" with a simple test of "current->ptrace".
The other tests in may_ptrace_stop all concern avoiding stopping
during a coredump. These tests are no longer necessary as it is now
guaranteed that fatal_signal_pending will be set if the code enters
ptrace_stop during a coredump. The code in ptrace_stop is guaranteed
not to stop if fatal_signal_pending returns true.
Until this change "ptrace_event(PTRACE_EVENT_EXIT)" could call
ptrace_stop without fatal_signal_pending being true, as signals are
dequeued in get_signal before calling do_exit. This is no longer
an issue as "ptrace_event(PTRACE_EVENT_EXIT)" is no longer reached
until after the coredump completes.
Link: https://lkml.kernel.org/r/874kaax26c.fsf@disp2133
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Linus Torvalds