In case of a use after free kernel oops, the freeing path of the object
is required to debug futher. In most of cases the object address is
present in one of the registers.
Thus check the register's address and if it belongs to slab, print its
alloc and free path.
e.g. in the below issue register r6 belongs to slab, and a use after
free issue occurred on one of its dereferenced values:
Unable to handle kernel paging request at virtual address 6b6b6b6f
....
pc : [<c0538afc>] lr : [<c0465674>] psr: 60000013
sp : c8927d40 ip : ffffefff fp : c8aa8020
r10: c8927e10 r9 : 00000001 r8 : 00400cc0
r7 : 00000000 r6 : c8ab0180 r5 : c1804a80 r4 : c8aa8008
r3 : c1a5661c r2 : 00000000 r1 : 6b6b6b6b r0 : c139bf48
.....
Register r6 information: slab kmalloc-64 start c8ab0140 data offset 64 pointer offset 0 size 64 allocated at meminfo_proc_show+0x40/0x4fc
meminfo_proc_show+0x40/0x4fc
seq_read_iter+0x18c/0x4c4
proc_reg_read_iter+0x84/0xac
generic_file_splice_read+0xe8/0x17c
splice_direct_to_actor+0xb8/0x290
do_splice_direct+0xa0/0xe0
do_sendfile+0x2d0/0x438
sys_sendfile64+0x12c/0x140
ret_fast_syscall+0x0/0x58
0xbeeacde4
Free path:
meminfo_proc_show+0x5c/0x4fc
seq_read_iter+0x18c/0x4c4
proc_reg_read_iter+0x84/0xac
generic_file_splice_read+0xe8/0x17c
splice_direct_to_actor+0xb8/0x290
do_splice_direct+0xa0/0xe0
do_sendfile+0x2d0/0x438
sys_sendfile64+0x12c/0x140
ret_fast_syscall+0x0/0x58
0xbeeacde4
Link: https://lkml.kernel.org/r/1615891032-29160-3-git-send-email-maninder1.s@samsung.com
Co-developed-by: Vaneet Narang <v.narang@samsung.com>
Signed-off-by: Vaneet Narang <v.narang@samsung.com>
Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On Qualcomm ARM32 platforms, the SMC call can return before it has
completed. If this occurs, the call can be restarted, but it requires
using the returned session ID value from the interrupted SMC call.
The ARM32 SMCC code already has the provision to add platform specific
quirks for things like this. So let's make use of it and add the
Qualcomm specific quirk (ARM_SMCCC_QUIRK_QCOM_A6) used by the QCOM_SCM
driver.
This change is similar to the below one added for ARM64 a while ago:
commit 82bcd08702 ("firmware: qcom: scm: Fix interrupted SCM calls")
Without this change, the Qualcomm ARM32 platforms like SDX55 will return
-EINVAL for SMC calls used for modem firmware loading and validation.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Many architectures duplicate similar shell scripts.
This commit converts ARM to use scripts/syscalltbl.sh.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Enabling function_graph tracer on ARM causes kernel panic, because the
function graph tracer updates the "return address" of a function in order
to insert a trace callback on function exit, it saves the function's
original return address in a return trace stack, but cpu_suspend() may not
return through the normal return path.
cpu_suspend() will resume directly via the cpu_resume path, but the return
trace stack has been set-up by the subfunctions of cpu_suspend(), which
makes the "return address" inconsistent with cpu_suspend().
This patch refers to Commit de818bd452
("arm64: kernel: pause/unpause function graph tracer in cpu_suspend()"),
fixes the issue by pausing/resuming the function graph tracer on the thread
executing cpu_suspend(), so that the function graph tracer state is kept
consistent across functions that enter power down states and never return
by effectively disabling graph tracer while they are executing.
Signed-off-by: louis.wang <liang26812@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
The commit 1879445dfa ("perf/core: Set event's default
::overflow_handler()") set a default event->overflow_handler in
perf_event_alloc(), and replace the check event->overflow_handler with
is_default_overflow_handler(), but one is missing.
Currently, the bp->overflow_handler can not be NULL. As a result,
enable_single_step() is always not invoked.
Comments from Zhen Lei:
https://patchwork.kernel.org/project/linux-arm-kernel/patch/20210207105934.2001-1-thunder.leizhen@huawei.com/
Fixes: 1879445dfa ("perf/core: Set event's default ::overflow_handler()")
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Wang Nan <wangnan0@huawei.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
The time pvops functions are the only ones left which might be
used in 32-bit mode and which return a 64-bit value.
Switch them to use the static_call() mechanism instead of pvops, as
this allows quite some simplification of the pvops implementation.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210311142319.4723-5-jgross@suse.com
The last (only?) user of this was removed in commit ba364fc752 ("ARM:
Kirkwood: Remove mach-kirkwood"), back in v3.17.
Link: https://lore.kernel.org/r/20210210235243.398810-1-joel@jms.id.au
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
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Merge tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block
Pull io_uring thread rewrite from Jens Axboe:
"This converts the io-wq workers to be forked off the tasks in question
instead of being kernel threads that assume various bits of the
original task identity.
This kills > 400 lines of code from io_uring/io-wq, and it's the worst
part of the code. We've had several bugs in this area, and the worry
is always that we could be missing some pieces for file types doing
unusual things (recent /dev/tty example comes to mind, userfaultfd
reads installing file descriptors is another fun one... - both of
which need special handling, and I bet it's not the last weird oddity
we'll find).
With these identical workers, we can have full confidence that we're
never missing anything. That, in itself, is a huge win. Outside of
that, it's also more efficient since we're not wasting space and code
on tracking state, or switching between different states.
I'm sure we're going to find little things to patch up after this
series, but testing has been pretty thorough, from the usual
regression suite to production. Any issue that may crop up should be
manageable.
There's also a nice series of further reductions we can do on top of
this, but I wanted to get the meat of it out sooner rather than later.
The general worry here isn't that it's fundamentally broken. Most of
the little issues we've found over the last week have been related to
just changes in how thread startup/exit is done, since that's the main
difference between using kthreads and these kinds of threads. In fact,
if all goes according to plan, I want to get this into the 5.10 and
5.11 stable branches as well.
That said, the changes outside of io_uring/io-wq are:
- arch setup, simple one-liner to each arch copy_thread()
implementation.
- Removal of net and proc restrictions for io_uring, they are no
longer needed or useful"
* tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block: (30 commits)
io-wq: remove now unused IO_WQ_BIT_ERROR
io_uring: fix SQPOLL thread handling over exec
io-wq: improve manager/worker handling over exec
io_uring: ensure SQPOLL startup is triggered before error shutdown
io-wq: make buffered file write hashed work map per-ctx
io-wq: fix race around io_worker grabbing
io-wq: fix races around manager/worker creation and task exit
io_uring: ensure io-wq context is always destroyed for tasks
arch: ensure parisc/powerpc handle PF_IO_WORKER in copy_thread()
io_uring: cleanup ->user usage
io-wq: remove nr_process accounting
io_uring: flag new native workers with IORING_FEAT_NATIVE_WORKERS
net: remove cmsg restriction from io_uring based send/recvmsg calls
Revert "proc: don't allow async path resolution of /proc/self components"
Revert "proc: don't allow async path resolution of /proc/thread-self components"
io_uring: move SQPOLL thread io-wq forked worker
io-wq: make io_wq_fork_thread() available to other users
io-wq: only remove worker from free_list, if it was there
io_uring: remove io_identity
io_uring: remove any grabbing of context
...
- Generalise byte swapping assembly
- Update debug addresses for STI
- Validate start of physical memory with DTB
- Do not clear SCTLR.nTLSMD in decompressor
- amba/locomo/sa1111 devices remove method return type is void
- address markers for KASAN in page table dump
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Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm
Pull ARM updates from Russell King:
- Generalise byte swapping assembly
- Update debug addresses for STI
- Validate start of physical memory with DTB
- Do not clear SCTLR.nTLSMD in decompressor
- amba/locomo/sa1111 devices remove method return type is void
- address markers for KASAN in page table dump
* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
ARM: 9065/1: OABI compat: fix build when EPOLL is not enabled
ARM: 9055/1: mailbox: arm_mhuv2: make remove callback return void
amba: Make use of bus_type functions
amba: Make the remove callback return void
vfio: platform: simplify device removal
amba: reorder functions
amba: Fix resource leak for drivers without .remove
ARM: 9054/1: arch/arm/mm/mmu.c: Remove duplicate header
ARM: 9053/1: arm/mm/ptdump:Add address markers for KASAN regions
ARM: 9051/1: vdso: remove unneded extra-y addition
ARM: 9050/1: Kconfig: Select ARCH_HAVE_NMI_SAFE_CMPXCHG where possible
ARM: 9049/1: locomo: make locomo bus's remove callback return void
ARM: 9048/1: sa1111: make sa1111 bus's remove callback return void
ARM: 9047/1: smp: remove unused variable
ARM: 9046/1: decompressor: Do not clear SCTLR.nTLSMD for ARMv7+ cores
ARM: 9045/1: uncompress: Validate start of physical memory against passed DTB
ARM: 9042/1: debug: no uncompress debugging while semihosting
ARM: 9041/1: sti LL_UART: add STiH418 SBC UART0 support
ARM: 9040/1: use DEBUG_UART_PHYS and DEBUG_UART_VIRT for sti LL_UART
ARM: 9039/1: assembler: generalize byte swapping macro into rev_l
When CONFIG_EPOLL is not set/enabled, sys_oabi-compat.c has build
errors. Fix these by surrounding them with ifdef CONFIG_EPOLL/endif
and providing stubs for the "EPOLL is not set" case.
../arch/arm/kernel/sys_oabi-compat.c: In function 'sys_oabi_epoll_ctl':
../arch/arm/kernel/sys_oabi-compat.c:257:6: error: implicit declaration of function 'ep_op_has_event' [-Werror=implicit-function-declaration]
257 | if (ep_op_has_event(op) &&
| ^~~~~~~~~~~~~~~
../arch/arm/kernel/sys_oabi-compat.c:264:9: error: implicit declaration of function 'do_epoll_ctl'; did you mean 'sys_epoll_ctl'? [-Werror=implicit-function-declaration]
264 | return do_epoll_ctl(epfd, op, fd, &kernel, false);
| ^~~~~~~~~~~~
Fixes: c281634c86 ("ARM: compat: remove KERNEL_DS usage in sys_oabi_epoll_ctl()")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com> # from an lkp .config file
Cc: linux-arm-kernel@lists.infradead.org
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: patches@armlinux.org.uk
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the
sense that we don't assign ->set_child_tid with our own structure. Just
ensure that every arch sets up the PF_IO_WORKER threads like kthreads
in the arch implementation of copy_thread().
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Giancarlo Ferrari reports the following oops while trying to use kexec:
Unable to handle kernel paging request at virtual address 80112f38
pgd = fd7ef03e
[80112f38] *pgd=0001141e(bad)
Internal error: Oops: 80d [#1] PREEMPT SMP ARM
...
This is caused by machine_kexec() trying to set the kernel text to be
read/write, so it can poke values into the relocation code before
copying it - and an interrupt occuring which changes the page tables.
The subsequent writes then hit read-only sections that trigger a
data abort resulting in the above oops.
Fix this by copying the relocation code, and then writing the variables
into the destination, thereby avoiding the need to make the kernel text
read/write.
Reported-by: Giancarlo Ferrari <giancarlo.ferrari89@gmail.com>
Tested-by: Giancarlo Ferrari <giancarlo.ferrari89@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Ensure that the signal page contains our poison instruction to increase
the protection against ROP attacks and also contains well defined
contents.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Not used anymore after refactoring:
arch/arm/kernel/smp.c: In function ‘show_ipi_list’:
arch/arm/kernel/smp.c:543:16: warning: variable ‘irq’ set but not used [-Wunused-but-set-variable]
543 | unsigned int irq;
Fixes: 88c637748e ("ARM: smp: Use irq_desc_kstat_cpu() in show_ipi_list()")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
accesses, inefficient and disfunctional code. The goal is to remove the
export of irq_to_desc() to prevent these things from creeping up again.
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Merge tag 'irq-core-2020-12-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
"This is the second attempt after the first one failed miserably and
got zapped to unblock the rest of the interrupt related patches.
A treewide cleanup of interrupt descriptor (ab)use with all sorts of
racy accesses, inefficient and disfunctional code. The goal is to
remove the export of irq_to_desc() to prevent these things from
creeping up again"
* tag 'irq-core-2020-12-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
genirq: Restrict export of irq_to_desc()
xen/events: Implement irq distribution
xen/events: Reduce irq_info:: Spurious_cnt storage size
xen/events: Only force affinity mask for percpu interrupts
xen/events: Use immediate affinity setting
xen/events: Remove disfunct affinity spreading
xen/events: Remove unused bind_evtchn_to_irq_lateeoi()
net/mlx5: Use effective interrupt affinity
net/mlx5: Replace irq_to_desc() abuse
net/mlx4: Use effective interrupt affinity
net/mlx4: Replace irq_to_desc() abuse
PCI: mobiveil: Use irq_data_get_irq_chip_data()
PCI: xilinx-nwl: Use irq_data_get_irq_chip_data()
NTB/msi: Use irq_has_action()
mfd: ab8500-debugfs: Remove the racy fiddling with irq_desc
pinctrl: nomadik: Use irq_has_action()
drm/i915/pmu: Replace open coded kstat_irqs() copy
drm/i915/lpe_audio: Remove pointless irq_to_desc() usage
s390/irq: Use irq_desc_kstat_cpu() in show_msi_interrupt()
parisc/irq: Use irq_desc_kstat_cpu() in show_interrupts()
...
- Rework phys/virt translation
- Add KASan support
- Move DT out of linear map region
- Use more PC-relative addressing in assembly
- Remove FP emulation handling while in kernel mode
- Link with '-z norelro'
- remove old check for GCC <= 4.2 in ARM unwinder code
- disable big endian if using clang's linker
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Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux
Pull ARM updates from Russell King:
- Rework phys/virt translation
- Add KASan support
- Move DT out of linear map region
- Use more PC-relative addressing in assembly
- Remove FP emulation handling while in kernel mode
- Link with '-z norelro'
- remove old check for GCC <= 4.2 in ARM unwinder code
- disable big endian if using clang's linker
* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (46 commits)
ARM: 9027/1: head.S: explicitly map DT even if it lives in the first physical section
ARM: 9038/1: Link with '-z norelro'
ARM: 9037/1: uncompress: Add OF_DT_MAGIC macro
ARM: 9036/1: uncompress: Fix dbgadtb size parameter name
ARM: 9035/1: uncompress: Add be32tocpu macro
ARM: 9033/1: arm/smp: Drop the macro S(x,s)
ARM: 9032/1: arm/mm: Convert PUD level pgtable helper macros into functions
ARM: 9031/1: hyp-stub: remove unused .L__boot_cpu_mode_offset symbol
ARM: 9044/1: vfp: use undef hook for VFP support detection
ARM: 9034/1: __div64_32(): straighten up inline asm constraints
ARM: 9030/1: entry: omit FP emulation for UND exceptions taken in kernel mode
ARM: 9029/1: Make iwmmxt.S support Clang's integrated assembler
ARM: 9028/1: disable KASAN in call stack capturing routines
ARM: 9026/1: unwind: remove old check for GCC <= 4.2
ARM: 9025/1: Kconfig: CPU_BIG_ENDIAN depends on !LD_IS_LLD
ARM: 9024/1: Drop useless cast of "u64" to "long long"
ARM: 9023/1: Spelling s/mmeory/memory/
ARM: 9022/1: Change arch/arm/lib/mem*.S to use WEAK instead of .weak
ARM: kvm: replace open coded VA->PA calculations with adr_l call
ARM: head.S: use PC relative insn sequence to calculate PHYS_OFFSET
...
The early ATAGS/DT mapping code uses SECTION_SHIFT to mask low order
bits of R2, and decides that no ATAGS/DTB were provided if the resulting
value is 0x0.
This means that on systems where DRAM starts at 0x0 (such as Raspberry
Pi), no explicit mapping of the DT will be created if R2 points into the
first 1 MB section of memory. This was not a problem before, because the
decompressed kernel is loaded at the base of DRAM and mapped using
sections as well, and so as long as the DT is referenced via a virtual
address that uses the same translation (the linear map, in this case),
things work fine.
However, commit 7a1be318f5 ("9012/1: move device tree mapping out of
linear region") changes this, and now the DT is referenced via a virtual
address that is disjoint from the linear mapping of DRAM, and so we need
the early code to create the DT mapping unconditionally.
So let's create the early DT mapping for any value of R2 != 0x0.
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Mapping between IPI type index and its string is direct without requiring
an additional offset. Hence the existing macro S(x, s) is now redundant
and can just be dropped. This also makes the code clean and simple.
Cc: Marc Zyngier <maz@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Commit aaac373317 ("ARM: kvm: replace open coded VA->PA calculations
with adr_l call") removed all uses of .L__boot_cpu_mode_offset, so there
is no longer a need to define it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
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Merge tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-block
Pull TIF_NOTIFY_SIGNAL updates from Jens Axboe:
"This sits on top of of the core entry/exit and x86 entry branch from
the tip tree, which contains the generic and x86 parts of this work.
Here we convert the rest of the archs to support TIF_NOTIFY_SIGNAL.
With that done, we can get rid of JOBCTL_TASK_WORK from task_work and
signal.c, and also remove a deadlock work-around in io_uring around
knowing that signal based task_work waking is invoked with the sighand
wait queue head lock.
The motivation for this work is to decouple signal notify based
task_work, of which io_uring is a heavy user of, from sighand. The
sighand lock becomes a huge contention point, particularly for
threaded workloads where it's shared between threads. Even outside of
threaded applications it's slower than it needs to be.
Roman Gershman <romger@amazon.com> reported that his networked
workload dropped from 1.6M QPS at 80% CPU to 1.0M QPS at 100% CPU
after io_uring was changed to use TIF_NOTIFY_SIGNAL. The time was all
spent hammering on the sighand lock, showing 57% of the CPU time there
[1].
There are further cleanups possible on top of this. One example is
TIF_PATCH_PENDING, where a patch already exists to use
TIF_NOTIFY_SIGNAL instead. Hopefully this will also lead to more
consolidation, but the work stands on its own as well"
[1] https://github.com/axboe/liburing/issues/215
* tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-block: (28 commits)
io_uring: remove 'twa_signal_ok' deadlock work-around
kernel: remove checking for TIF_NOTIFY_SIGNAL
signal: kill JOBCTL_TASK_WORK
io_uring: JOBCTL_TASK_WORK is no longer used by task_work
task_work: remove legacy TWA_SIGNAL path
sparc: add support for TIF_NOTIFY_SIGNAL
riscv: add support for TIF_NOTIFY_SIGNAL
nds32: add support for TIF_NOTIFY_SIGNAL
ia64: add support for TIF_NOTIFY_SIGNAL
h8300: add support for TIF_NOTIFY_SIGNAL
c6x: add support for TIF_NOTIFY_SIGNAL
alpha: add support for TIF_NOTIFY_SIGNAL
xtensa: add support for TIF_NOTIFY_SIGNAL
arm: add support for TIF_NOTIFY_SIGNAL
microblaze: add support for TIF_NOTIFY_SIGNAL
hexagon: add support for TIF_NOTIFY_SIGNAL
csky: add support for TIF_NOTIFY_SIGNAL
openrisc: add support for TIF_NOTIFY_SIGNAL
sh: add support for TIF_NOTIFY_SIGNAL
um: add support for TIF_NOTIFY_SIGNAL
...
This cleans up two ancient timer features that were never completed in
the past, CONFIG_GENERIC_CLOCKEVENTS and CONFIG_ARCH_USES_GETTIMEOFFSET.
There was only one user left for the ARCH_USES_GETTIMEOFFSET variant
of clocksource implementations, the ARM EBSA110 platform. Rather than
changing to use modern timekeeping, we remove the platform entirely as
Russell no longer uses his machine and nobody else seems to have one
any more.
The conditional code for using arch_gettimeoffset() is removed as
a result.
For CONFIG_GENERIC_CLOCKEVENTS, there are still a couple of platforms
not using clockevent drivers: parisc, ia64, most of m68k, and one
Arm platform. These all do timer ticks slighly differently, and this
gets cleaned up to the point they at least all call the same helper
function. Instead of most platforms using 'select GENERIC_CLOCKEVENTS'
in Kconfig, the polarity is now reversed, with the few remaining ones
selecting LEGACY_TIMER_TICK instead.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Merge tag 'asm-generic-timers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull asm-generic cross-architecture timer cleanup from Arnd Bergmann:
"This cleans up two ancient timer features that were never completed in
the past, CONFIG_GENERIC_CLOCKEVENTS and CONFIG_ARCH_USES_GETTIMEOFFSET.
There was only one user left for the ARCH_USES_GETTIMEOFFSET variant
of clocksource implementations, the ARM EBSA110 platform. Rather than
changing to use modern timekeeping, we remove the platform entirely as
Russell no longer uses his machine and nobody else seems to have one
any more.
The conditional code for using arch_gettimeoffset() is removed as a
result.
For CONFIG_GENERIC_CLOCKEVENTS, there are still a couple of platforms
not using clockevent drivers: parisc, ia64, most of m68k, and one Arm
platform. These all do timer ticks slighly differently, and this gets
cleaned up to the point they at least all call the same helper
function.
Instead of most platforms using 'select GENERIC_CLOCKEVENTS' in
Kconfig, the polarity is now reversed, with the few remaining ones
selecting LEGACY_TIMER_TICK instead"
* tag 'asm-generic-timers-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
timekeeping: default GENERIC_CLOCKEVENTS to enabled
timekeeping: remove xtime_update
m68k: remove timer_interrupt() function
m68k: change remaining timers to legacy_timer_tick
m68k: m68328: use legacy_timer_tick()
m68k: sun3/sun3c: use legacy_timer_tick
m68k: split heartbeat out of timer function
m68k: coldfire: use legacy_timer_tick()
parisc: use legacy_timer_tick
ARM: rpc: use legacy_timer_tick
ia64: convert to legacy_timer_tick
timekeeping: add CONFIG_LEGACY_TIMER_TICK
timekeeping: remove arch_gettimeoffset
net: remove am79c961a driver
ARM: remove ebsa110 platform
Pull regset updates from Al Viro:
"Dead code removal, mostly.
The only exception is a bit of cleanups on itanic (getting rid of
redundant stack unwinds - each access_uarea() call does it and we call
that 7 times in a row in ptrace_[sg]etregs(), *after* having done it
ourselves in the caller; location where the user registers have been
spilled won't change under us, and we can bloody well just call
access_elf_reg() directly, giving it the unw_frame_info we'd
calculated for our own purposes)"
* 'regset.followup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
c6x: kill ELF_CORE_COPY_FPREGS
whack-a-mole: USE_ELF_CORE_DUMP
[ia64] ptrace_[sg]etregs(): use access_elf_reg() instead of access_uarea()
[ia64] missed cleanups from switch to regset coredumps
arm: kill dump_task_regs()
Don't allow splitting of vm_special_mapping's. It affects vdso/vvar
areas. Uprobes have only one page in xol_area so they aren't affected.
Those restrictions were enforced by checks in .mremap() callbacks.
Restrict resizing with generic .split() callback.
Link: https://lkml.kernel.org/r/20201013013416.390574-7-dima@arista.com
Signed-off-by: Dmitry Safonov <dima@arista.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are a couple of problems with the exception entry code that deals
with FP exceptions (which are reported as UND exceptions) when building
the kernel in Thumb2 mode:
- the conditional branch to vfp_kmode_exception in vfp_support_entry()
may be out of range for its target, depending on how the linker decides
to arrange the sections;
- when the UND exception is taken in kernel mode, the emulation handling
logic is entered via the 'call_fpe' label, which means we end up using
the wrong value/mask pairs to match and detect the NEON opcodes.
Since UND exceptions in kernel mode are unlikely to occur on a hot path
(as opposed to the user mode version which is invoked for VFP support
code and lazy restore), we can use the existing undef hook machinery for
any kernel mode instruction emulation that is needed, including calling
the existing vfp_kmode_exception() routine for unexpected cases. So drop
the call to call_fpe, and instead, install an undef hook that will get
called for NEON and VFP instructions that trigger an UND exception in
kernel mode.
While at it, make sure that the PC correction is accurate for the
execution mode where the exception was taken, by checking the PSR
Thumb bit.
Cc: Dmitry Osipenko <digetx@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Fixes: eff8728fe6 ("vmlinux.lds.h: Add PGO and AutoFDO input sections")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This patch replaces 6 IWMMXT instructions Clang's integrated assembler
does not support in iwmmxt.S using macros, while making sure GNU
assembler still emit the same instructions. This should be easier than
providing full IWMMXT support in Clang. This is one of the last bits of
kernel code that could be compiled but not assembled with clang. Once
all of it works with IAS, we no longer need to special-case 32-bit Arm
in Kbuild, or turn off CONFIG_IWMMXT when build-testing.
"Intel Wireless MMX Technology - Developer Guide - August, 2002" should
be referenced for the encoding schemes of these extensions.
Link: https://github.com/ClangBuiltLinux/linux/issues/975
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Jian Cai <jiancai@google.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
KASAN uses the routines in stacktrace.c to capture the call stack each
time memory gets allocated or freed. Some of these routines are also
used to log CPU and memory context when exceptions are taken, and so
in some cases, memory accesses may be made that are not strictly in
line with the KASAN constraints, and may therefore trigger false KASAN
positives.
So follow the example set by other architectures, and simply disable
KASAN instrumentation for these routines.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Since
commit 0bddd227f3 ("Documentation: update for gcc 4.9 requirement")
the minimum supported version of GCC is gcc-4.9. It's now safe to remove
this code.
Link: https://github.com/ClangBuiltLinux/linux/issues/427
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
idle path. Similar to the entry path the low level idle functions have to
be non-instrumentable.
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Merge tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
"Two more places which invoke tracing from RCU disabled regions in the
idle path.
Similar to the entry path the low level idle functions have to be
non-instrumentable"
* tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
intel_idle: Fix intel_idle() vs tracing
sched/idle: Fix arch_cpu_idle() vs tracing
We call arch_cpu_idle() with RCU disabled, but then use
local_irq_{en,dis}able(), which invokes tracing, which relies on RCU.
Switch all arch_cpu_idle() implementations to use
raw_local_irq_{en,dis}able() and carefully manage the
lockdep,rcu,tracing state like we do in entry.
(XXX: we really should change arch_cpu_idle() to not return with
interrupts enabled)
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org
Wire up TIF_NOTIFY_SIGNAL handling for arm.
Cc: linux-arm-kernel@lists.infradead.org
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
As "u64" is equivalent to "unsigned long long", there is no need to cast
a "u64" parameter for printing it using the "0x%08llx" format specifier.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Fix a misspelling of the word "memory".
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
struct perf_sample_data lives on-stack, we should be careful about it's
size. Furthermore, the pt_regs copy in there is only because x86_64 is a
trainwreck, solve it differently.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20201030151955.258178461@infradead.org
rpc is the only user of the timer_tick() function now, and can
just call the newly added generic version instead.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Russell said that he is no longer using this machine, and it seems that
nobody else has in a long time, so it's time to say goodbye to it.
As this is the last platform using CONFIG_ARCH_USES_GETTIMEOFFSET,
there are some follow-up patches to remove that as well.
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Replace the open coded calculations of the actual physical address
of the KVM stub vector table with a single adr_l invocation.
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Replace the open coded arithmetic with a simple adr_l/sub pair. This
removes some open coded arithmetic involving virtual addresses, avoids
literal pools on v7+, and slightly reduces the footprint of the code.
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Replace the open coded PC relative offset calculations with adr_l and
ldr_l invocations. This removes some open coded PC relative arithmetic,
avoids literal pools on v7+, and slightly reduces the footprint of the
code. Note that ALT_SMP() expects a single instruction so move the macro
invocation after it.
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Now that calling __do_fixup_smp_on_up() can be done without passing
the physical-to-virtual offset in r3, we can replace the open coded
PC relative offset calculations with a pair of adr_l invocations. This
removes some open coded arithmetic involving virtual addresses, avoids
literal pools on v7+, and slightly reduces the footprint of the code.
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Currently, the .alt.smp.init section contains the virtual addresses
of the patch sites. Since patching may occur both before and after
switching into virtual mode, this requires some manual handling of
the address when applying the UP alternative.
Let's simplify this by using relative offsets in the table entries:
this allows us to simply add each entry's address to its contents,
regardless of whether we are running in virtual mode or not.
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Replace the open coded PC relative offset calculations with adr_l
and ldr_l invocations. This removes some open coded arithmetic
involving virtual addresses, avoids literal pools on v7+, and slightly
reduces the footprint of the code.
Note that it also removes a stale comment about the contents of r6.
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Replace the open coded PC relative offset calculations involving
__turn_mmu_on and __turn_mmu_on_end with a pair of adr_l invocations.
This removes some open coded arithmetic involving virtual addresses,
avoids literal pools on v7+, and slightly reduces the footprint of the
code.
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Replace the open coded PC relative offset calculations with a pair of
adr_l invocations. This removes some open coded arithmetic involving
virtual addresses, avoids literal pools on v7+, and slightly reduces
the footprint of the code.
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The ARM kernel's linear map starts at PAGE_OFFSET, which maps to a
physical address (PHYS_OFFSET) that is platform specific, and is
discovered at boot. Since we don't want to slow down translations
between physical and virtual addresses by keeping the offset in a
variable in memory, we implement this by patching the code performing
the translation, and putting the offset between PAGE_OFFSET and the
start of physical RAM directly into the instruction opcodes.
As we only patch up to 8 bits of offset, yielding 4 GiB >> 8 == 16 MiB
of granularity, we have to round up PHYS_OFFSET to the next multiple if
the start of physical RAM is not a multiple of 16 MiB. This wastes some
physical RAM, since the memory that was skipped will now live below
PAGE_OFFSET, making it inaccessible to the kernel.
We can improve this by changing the patchable sequences and the patching
logic to carry more bits of offset: 11 bits gives us 4 GiB >> 11 == 2 MiB
of granularity, and so we will never waste more than that amount by
rounding up the physical start of DRAM to the next multiple of 2 MiB.
(Note that 2 MiB granularity guarantees that the linear mapping can be
created efficiently, whereas less than 2 MiB may result in the linear
mapping needing another level of page tables)
This helps Zhen Lei's scenario, where the start of DRAM is known to be
occupied. It also helps EFI boot, which relies on the firmware's page
allocator to allocate space for the decompressed kernel as low as
possible. And if the KASLR patches ever land for 32-bit, it will give
us 3 more bits of randomization of the placement of the kernel inside
the linear region.
For the ARM code path, it simply comes down to using two add/sub
instructions instead of one for the carryless version, and patching
each of them with the correct immediate depending on the rotation
field. For the LPAE calculation, which has to deal with a carry, it
patches the MOVW instruction with up to 12 bits of offset (but we only
need 11 bits anyway)
For the Thumb2 code path, patching more than 11 bits of displacement
would be somewhat cumbersome, but the 11 bits we need fit nicely into
the second word of the u16[2] opcode, so we simply update the immediate
assignment and the left shift to create an addend of the right magnitude.
Suggested-by: Zhen Lei <thunder.leizhen@huawei.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
In preparation for reducing the phys-to-virt minimum relative alignment
from 16 MiB to 2 MiB, switch to patchable sequences involving MOVW
instructions that can more easily be manipulated to carry a 12-bit
immediate. Note that the non-LPAE ARM sequence is not updated: MOVW
may not be supported on non-LPAE platforms, and the sequence itself
can be updated more easily to apply the 12 bits of displacement.
For Thumb2, which has many more versions of opcodes, switch to a sequence
that can be patched by the same patching code for both versions. Note
that the Thumb2 opcodes for MOVW and MVN are unambiguous, and have no
rotation bits in their immediate fields, so there is no need to use
placeholder constants in the asm blocks.
While at it, drop the 'volatile' qualifiers from the asm blocks: the
code does not have any side effects that are invisible to the compiler,
so it is free to omit these sequences if the outputs are not used.
Suggested-by: Russell King <linux@armlinux.org.uk>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Declutter the code in __fixup_pv_table() by using the new adr_l/str_l
macros to take PC relative references to external symbols, and by
using the value of PHYS_OFFSET passed in r8 to calculate the p2v
offset.
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Linus Torvalds