There are so many places that build struct siginfo by hand that at
least one of them is bound to get it wrong. A handful of cases in the
kernel arguably did just that when using the errno field of siginfo to
pass no errno values to userspace. The usage is limited to a single
si_code so at least does not mess up anything else.
Encapsulate this questionable pattern in a helper function so
that the userspace ABI is preserved.
Update all of the places that use this pattern to use the new helper
function.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The siginfo structure has all manners of holes with the result that a
structure initializer is not guaranteed to initialize all of the bits.
As we have to copy the structure to userspace don't even try to use
a structure initializer. Instead use clear_siginfo followed by initializing
selected fields. This gives a guarantee that uninitialized kernel memory
is not copied to userspace.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Instead of jumpping while !is_compat_task placee all of the code
inside of an if (is_compat_task) block. This allows the int i
variable to be properly limited to the compat block no matter how the
rest of ptrace_hbptriggered changes.
In a following change a non-variable declaration will preceed
was made independent to ensure the code is easy to review.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This patch defines and implements a new regset NT_ARM_SVE, which
describes a thread's SVE register state. This allows a debugger to
manipulate the SVE state, as well as being included in ELF
coredumps for post-mortem debugging.
Because the regset size and layout are dependent on the thread's
current vector length, it is not possible to define a C struct to
describe the regset contents as is done for existing regsets.
Instead, and for the same reasons, NT_ARM_SVE is based on the
freeform variable-layout approach used for the SVE signal frame.
Additionally, to reduce debug overhead when debugging threads that
might or might not have live SVE register state, NT_ARM_SVE may be
presented in one of two different formats: the old struct
user_fpsimd_state format is embedded for describing the state of a
thread with no live SVE state, whereas a new variable-layout
structure is embedded for describing live SVE state. This avoids a
debugger needing to poll NT_PRFPREG in addition to NT_ARM_SVE, and
allows existing userspace code to handle the non-SVE case without
too much modification.
For this to work, NT_ARM_SVE is defined with a fixed-format header
of type struct user_sve_header, which the recipient can use to
figure out the content, size and layout of the reset of the regset.
Accessor macros are defined to allow the vector-length-dependent
parts of the regset to be manipulated.
Signed-off-by: Alan Hayward <alan.hayward@arm.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alex Bennée <alex.bennee@linaro.org>
Cc: Okamoto Takayuki <tokamoto@jp.fujitsu.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Before we add yet another stack to the kernel, it would be nice to
ensure that we consistently organise stack definitions and related
helper functions.
This patch moves the basic IRQ stack defintions to <asm/memory.h> to
live with their task stack counterparts. Helpers used for unwinding are
moved into <asm/stacktrace.h>, where subsequent patches will add helpers
for other stacks. Includes are fixed up accordingly.
This patch is a pure refactoring -- there should be no functional
changes as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Our IRQ_STACK_PTR() and on_irq_stack() helpers both take a cpu argument,
used to generate a percpu address. In all cases, they are passed
{raw_,}smp_processor_id(), so this parameter is redundant.
Since {raw_,}smp_processor_id() use a percpu variable internally, this
approach means we generate a percpu offset to find the current cpu, then
use this to index an array of percpu offsets, which we then use to find
the current CPU's IRQ stack pointer. Thus, most of the work is
redundant.
Instead, we can consistently use raw_cpu_ptr() to generate the CPU's
irq_stack pointer by simply adding the percpu offset to the irq_stack
address, which is simpler in both respects.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
The -1 "no syscall" value is written in various ways, shared with
the user ABI in some places, and generally obscure.
This patch attempts to make things a little more consistent and
readable by replacing all these uses with a single #define. A
couple of symbolic helpers are provided to clarify the intent
further.
Because the in-syscall check in do_signal() is changed from >= 0 to
!= NO_SYSCALL by this patch, different behaviour may be observable
if syscallno is set to values less than -1 by a tracer. However,
this is not different from the behaviour that is already observable
if a tracer sets syscallno to a value >= __NR_(compat_)syscalls.
It appears that this can cause spurious syscall restarting, but
that is not a new behaviour either, and does not appear harmful.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The upper 32 bits of the syscallno field in thread_struct are
handled inconsistently, being sometimes zero extended and sometimes
sign-extended. In fact, only the lower 32 bits seem to have any
real significance for the behaviour of the code: it's been OK to
handle the upper bits inconsistently because they don't matter.
Currently, the only place I can find where those bits are
significant is in calling trace_sys_enter(), which may be
unintentional: for example, if a compat tracer attempts to cancel a
syscall by passing -1 to (COMPAT_)PTRACE_SET_SYSCALL at the
syscall-enter-stop, it will be traced as syscall 4294967295
rather than -1 as might be expected (and as occurs for a native
tracer doing the same thing). Elsewhere, reads of syscallno cast
it to an int or truncate it.
There's also a conspicuous amount of code and casting to bodge
around the fact that although semantically an int, syscallno is
stored as a u64.
Let's not pretend any more.
In order to preserve the stp x instruction that stores the syscall
number in entry.S, this patch special-cases the layout of struct
pt_regs for big endian so that the newly 32-bit syscallno field
maps onto the low bits of the stored value. This is not beautiful,
but benchmarking of the getpid syscall on Juno suggests indicates a
minor slowdown if the stp is split into an stp x and stp w.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Now that compat_vfp_get() uses the regset API to copy the FPSCR
value out to userspace, compat_vfp_set() looks inconsistent. In
particular, compat_vfp_set() will fail if called with kbuf != NULL
&& ubuf == NULL (which is valid usage according to the regset API).
This patch fixes compat_vfp_set() to use user_regset_copyin(),
similarly to compat_vfp_get().
This also squashes a sparse warning triggered by the cast that
drops __user when calling get_user().
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
compat_vfp_set() checks for userspace trying to write an excessive
amount of data to the regset. However this check is conspicuous
for its absence from every other _set() in the arm64 ptrace
implementation. In fact, the core ptrace_regset() already clamps
userspace's iov_len to the regset size before the individual regset
.{get,set}() methods get called.
This patch removes the redundant check.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
If get_user() fails when reading the new FPSCR value from userspace
in compat_vfp_get(), then garbage* will be written to the task's
FPSR and FPCR registers.
This patch prevents this by checking the return from get_user()
first.
[*] Actually, zero, due to the behaviour of get_user() on error, but
that's still not what userspace expects.
Fixes: 478fcb2cdb ("arm64: Debugging support")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
When reading current's user-writable TLS register (which occurs
when dumping core for native tasks), it is possible that userspace
has modified it since the time the task was last scheduled out.
The new TLS register value is not guaranteed to have been written
immediately back to thread_struct in this case.
As a result, a coredump can capture stale data for this register.
Reading the register for a stopped task via ptrace is unaffected.
For native tasks, this patch explicitly flushes the TPIDR_EL0
register back to thread_struct before dumping when operating on
current, thus ensuring that coredump contents are up to date. For
compat tasks, the TLS register is not user-writable and so cannot
be out of sync, so no flush is required in compat_tls_get().
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
When reading the FPSIMD state of current (which occurs when dumping
core), it is possible that userspace has modified the FPSIMD
registers since the time the task was last scheduled out. Such
changes are not guaranteed to be reflected immedately in
thread_struct.
As a result, a coredump can contain stale values for these
registers. Reading the registers of a stopped task via ptrace is
unaffected.
This patch explicitly flushes the CPU state back to thread_struct
before dumping when operating on current, thus ensuring that
coredump contents are up to date.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently, VFP registers are omitted from coredumps for compat
processes, due to a bug in the REGSET_COMPAT_VFP regset
implementation.
compat_vfp_get() needs to transfer non-contiguous data from
thread_struct.fpsimd_state, and uses put_user() to handle the
offending trailing word (FPSCR). This fails when copying to a
kernel address (i.e., kbuf && !ubuf), which is what happens when
dumping core. As a result, the ELF coredump core code silently
omits the NT_ARM_VFP note from the dump.
It would be possible to work around this with additional special
case code for the put_user(), but since user_regset_copyout() is
explicitly designed to handle this scenario it is cleaner to port
the put_user() to a user_regset_copyout() call, which this patch
does.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/task_stack.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We cannot preserve partial fields for hardware breakpoints, because
the values written by userspace to the hardware breakpoint
registers can't subsequently be recovered intact from the hardware.
So, just reject attempts to write incomplete fields with -EINVAL.
Cc: <stable@vger.kernel.org> # 3.7.x-
Fixes: 478fcb2cdb ("arm64: Debugging support")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <Will.Deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Ensure that if userspace supplies insufficient data to
PTRACE_SETREGSET to fill all the registers, the thread's old
registers are preserved.
Cc: <stable@vger.kernel.org> # 4.3.x-
Fixes: 5d220ff942 ("arm64: Better native ptrace support for compat tasks")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <Will.Deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Ensure that if userspace supplies insufficient data to
PTRACE_SETREGSET to fill all the registers, the thread's old
registers are preserved.
Cc: <stable@vger.kernel.org> # 3.19.x-
Fixes: 766a85d7bc ("arm64: ptrace: add NT_ARM_SYSTEM_CALL regset")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <Will.Deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Ensure that if userspace supplies insufficient data to
PTRACE_SETREGSET to fill all the registers, the thread's old
registers are preserved.
Cc: <stable@vger.kernel.org> # 3.7.x-
Fixes: 478fcb2cdb ("arm64: Debugging support")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <Will.Deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
ARM64 hardware supports watchpoint at any double word aligned address.
However, it can select any consecutive bytes from offset 0 to 7 from that
base address. For example, if base address is programmed as 0x420030 and
byte select is 0x1C, then access of 0x420032,0x420033 and 0x420034 will
generate a watchpoint exception.
Currently, we do not have such modularity. We can only program byte,
halfword, word and double word access exception from any base address.
This patch adds support to overcome above limitations.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Pull security subsystem updates from James Morris:
"Highlights:
- TPM core and driver updates/fixes
- IPv6 security labeling (CALIPSO)
- Lots of Apparmor fixes
- Seccomp: remove 2-phase API, close hole where ptrace can change
syscall #"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (156 commits)
apparmor: fix SECURITY_APPARMOR_HASH_DEFAULT parameter handling
tpm: Add TPM 2.0 support to the Nuvoton i2c driver (NPCT6xx family)
tpm: Factor out common startup code
tpm: use devm_add_action_or_reset
tpm2_i2c_nuvoton: add irq validity check
tpm: read burstcount from TPM_STS in one 32-bit transaction
tpm: fix byte-order for the value read by tpm2_get_tpm_pt
tpm_tis_core: convert max timeouts from msec to jiffies
apparmor: fix arg_size computation for when setprocattr is null terminated
apparmor: fix oops, validate buffer size in apparmor_setprocattr()
apparmor: do not expose kernel stack
apparmor: fix module parameters can be changed after policy is locked
apparmor: fix oops in profile_unpack() when policy_db is not present
apparmor: don't check for vmalloc_addr if kvzalloc() failed
apparmor: add missing id bounds check on dfa verification
apparmor: allow SYS_CAP_RESOURCE to be sufficient to prlimit another task
apparmor: use list_next_entry instead of list_entry_next
apparmor: fix refcount race when finding a child profile
apparmor: fix ref count leak when profile sha1 hash is read
apparmor: check that xindex is in trans_table bounds
...
Add HAVE_REGS_AND_STACK_ACCESS_API feature for arm64, including supporting
functions and defines.
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
[catalin.marinas@arm.com: Remove unused functions]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Close the hole where ptrace can change a syscall out from under seccomp.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Currently, if arch code wants to supply seccomp_data directly to
seccomp (which is generally much faster than having seccomp do it
using the syscall_get_xyz() API), it has to use the two-phase
seccomp hooks. Add it to the easy hooks, too.
Cc: linux-arch@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
We validate pstate using PSR_MODE32_BIT, which is part of the
user-provided pstate (and cannot be trusted). Also, we conflate
validation of AArch32 and AArch64 pstate values, making the code
difficult to reason about.
Instead, validate the pstate value based on the associated task. The
task may or may not be current (e.g. when using ptrace), so this must be
passed explicitly by callers. To avoid circular header dependencies via
sched.h, is_compat_task is pulled out of asm/ptrace.h.
To make the code possible to reason about, the AArch64 and AArch32
validation is split into separate functions. Software must respect the
RES0 policy for SPSR bits, and thus the kernel mirrors the hardware
policy (RAZ/WI) for bits as-yet unallocated. When these acquire an
architected meaning writes may be permitted (potentially with additional
validation).
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Dave Martin <dave.martin@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Make sure to clear out any ptrace singlestep state when a ptrace(2)
PTRACE_DETACH call is made on arm64 systems.
Otherwise, the previously ptraced task will die off with a SIGTRAP
signal if the debugger just previously singlestepped the ptraced task.
Cc: <stable@vger.kernel.org>
Signed-off-by: John Blackwood <john.blackwood@ccur.com>
[will: added comment to justify why this is in the arch code]
Signed-off-by: Will Deacon <will.deacon@arm.com>
The compat ptrace interface allows access to the TLS register, hardware
breakpoints and watchpoints, syscall number. However, a native task
using the native ptrace interface to debug compat tasks (e.g. multi-arch
gdb) only has access to the general and VFP register sets. The compat
ptrace interface cannot be accessed from a native task.
This patch adds a new user_aarch32_ptrace_view which contains the TLS,
hardware breakpoint/watchpoint and syscall number regsets in addition to
the existing GPR and VFP regsets. This view is backwards compatible with
the previous kernels. Core dumping of 32-bit tasks and compat ptrace are
not affected since the original user_aarch32_view is preserved.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Yao Qi <yao.qi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
secure_computing() is called first in syscall_trace_enter() so that
a system call will be aborted quickly without doing succeeding syscall
tracing if seccomp rules want to deny that system call.
On compat task, syscall numbers for system calls allowed in seccomp mode 1
are different from those on normal tasks, and so _NR_seccomp_xxx_32's need
to be redefined.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This regeset is intended to be used to get and set a system call number
while tracing.
There was some discussion about possible approaches to do so:
(1) modify x8 register with ptrace(PTRACE_SETREGSET) indirectly,
and update regs->syscallno later on in syscall_trace_enter(), or
(2) define a dedicated regset for this purpose as on s390, or
(3) support ptrace(PTRACE_SET_SYSCALL) as on arch/arm
Thinking of the fact that user_pt_regs doesn't expose 'syscallno' to
tracer as well as that secure_computing() expects a changed syscall number,
especially case of -1, to be visible before this function returns in
syscall_trace_enter(), (1) doesn't work well.
We will take (2) since it looks much cleaner.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Pull audit updates from Eric Paris:
"So this change across a whole bunch of arches really solves one basic
problem. We want to audit when seccomp is killing a process. seccomp
hooks in before the audit syscall entry code. audit_syscall_entry
took as an argument the arch of the given syscall. Since the arch is
part of what makes a syscall number meaningful it's an important part
of the record, but it isn't available when seccomp shoots the
syscall...
For most arch's we have a better way to get the arch (syscall_get_arch)
So the solution was two fold: Implement syscall_get_arch() everywhere
there is audit which didn't have it. Use syscall_get_arch() in the
seccomp audit code. Having syscall_get_arch() everywhere meant it was
a useless flag on the stack and we could get rid of it for the typical
syscall entry.
The other changes inside the audit system aren't grand, fixed some
records that had invalid spaces. Better locking around the task comm
field. Removing some dead functions and structs. Make some things
static. Really minor stuff"
* git://git.infradead.org/users/eparis/audit: (31 commits)
audit: rename audit_log_remove_rule to disambiguate for trees
audit: cull redundancy in audit_rule_change
audit: WARN if audit_rule_change called illegally
audit: put rule existence check in canonical order
next: openrisc: Fix build
audit: get comm using lock to avoid race in string printing
audit: remove open_arg() function that is never used
audit: correct AUDIT_GET_FEATURE return message type
audit: set nlmsg_len for multicast messages.
audit: use union for audit_field values since they are mutually exclusive
audit: invalid op= values for rules
audit: use atomic_t to simplify audit_serial()
kernel/audit.c: use ARRAY_SIZE instead of sizeof/sizeof[0]
audit: reduce scope of audit_log_fcaps
audit: reduce scope of audit_net_id
audit: arm64: Remove the audit arch argument to audit_syscall_entry
arm64: audit: Add audit hook in syscall_trace_enter/exit()
audit: x86: drop arch from __audit_syscall_entry() interface
sparc: implement is_32bit_task
sparc: properly conditionalize use of TIF_32BIT
...
The arm64 tree added calls to audit_syscall_entry() and rightly included
the syscall number. The interface has since been changed to not need
the syscall number. As such, arm64 should no longer pass that value.
Signed-off-by: Eric Paris <eparis@redhat.com>
This patch adds auditing functions on entry to or exit from
every system call invocation.
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
copy_{to,from}_user return the number of bytes remaining on failure, not
an error code.
This patch returns -EFAULT when the copy operation didn't complete,
rather than expose the number of bytes not copied directly to userspace.
Signed-off-by: Will Deacon <will.deacon@arm.com>
I'm not sure what I was on when I wrote this, but when iterating over
the hardware watchpoint array (hbp_watch_array), our index is off by
ARM_MAX_BRP, so we walk off the end of our thread_struct...
... except, a dodgy condition in the loop means that it never executes
at all (bp cannot be NULL).
This patch fixes the code so that we remove the bp check and use the
correct index for accessing the watchpoint structures.
Cc: <stable@vger.kernel.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
For some reason, the audit patches didn't make it out of -next this
merge window, so revert our temporary hack and let the audit guys deal
with fixing up -next.
This reverts commit 2a8f45b040.
Signed-off-by: Will Deacon <will.deacon@arm.com>
This is a temporary patch to be able to compile the kernel in linux-next
where the audit_syscall_* API has been changed. To be reverted once the
proper arm64 fix can be applied.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This patch adds auditing functions on entry to or exit from
every system call invocation.
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Currently core file of aarch32 process prstatus note has empty
registers set. As result aarch32 core files create by V8 kernel are
not very useful.
It happens because compat_gpr_get and compat_gpr_set functions can
copy registers values to/from either kbuf or ubuf. ELF core file
collection function fill_thread_core_info calls compat_gpr_get
with kbuf set and ubuf set to 0. But current compat_gpr_get and
compat_gpr_set function handle copy to/from only ubuf case.
Fix is to handle kbuf and ubuf as two separate cases in similar
way as other functions like user_regset_copyout, user_regset_copyin do.
Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Our compat PTRACE_POKEUSR implementation simply passes the user data to
regset_copy_from_user after some simple range checking. Unfortunately,
the data in question has already been copied to the kernel stack by this
point, so the subsequent access_ok check fails and the ptrace request
returns -EFAULT. This causes problems tracing fork() with older versions
of strace.
This patch briefly changes the fs to KERNEL_DS, so that the access_ok
check passes even with a kernel address.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This patch allows system call entry or exit to be traced as ftrace events,
ie. sys_enter_*/sys_exit_*, if CONFIG_FTRACE_SYSCALLS is enabled.
Those events appear and can be controlled under
${sysfs}/tracing/events/syscalls/
Please note that we can't trace compat system calls here because
AArch32 mode does not share the same syscall table with AArch64.
Just define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS in order to avoid unexpected
results (bogus syscalls reported or even hang-up).
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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Merge tag 'for-3.16' of git://git.linaro.org/people/ard.biesheuvel/linux-arm into upstream
FPSIMD register bank context switching and crypto algorithms
optimisations for arm64 from Ard Biesheuvel.
* tag 'for-3.16' of git://git.linaro.org/people/ard.biesheuvel/linux-arm:
arm64/crypto: AES-ECB/CBC/CTR/XTS using ARMv8 NEON and Crypto Extensions
arm64: pull in <asm/simd.h> from asm-generic
arm64/crypto: AES in CCM mode using ARMv8 Crypto Extensions
arm64/crypto: AES using ARMv8 Crypto Extensions
arm64/crypto: GHASH secure hash using ARMv8 Crypto Extensions
arm64/crypto: SHA-224/SHA-256 using ARMv8 Crypto Extensions
arm64/crypto: SHA-1 using ARMv8 Crypto Extensions
arm64: add support for kernel mode NEON in interrupt context
arm64: defer reloading a task's FPSIMD state to userland resume
arm64: add abstractions for FPSIMD state manipulation
asm-generic: allow generic unaligned access if the arch supports it
Conflicts:
arch/arm64/include/asm/thread_info.h
Some kernel files may include both linux/compat.h and asm/compat.h directly
or indirectly. Since both header files contain is_compat_task() under
!CONFIG_COMPAT, compiling them with !CONFIG_COMPAT will eventually fail.
Such files include kernel/auditsc.c, kernel/seccomp.c and init/do_mountfs.c
(do_mountfs.c may read asm/compat.h via asm/ftrace.h once ftrace is
implemented).
So this patch proactively
1) removes is_compat_task() under !CONFIG_COMPAT from asm/compat.h
2) replaces asm/compat.h to linux/compat.h in kernel/*.c,
but asm/compat.h is still necessary in ptrace.c and process.c because
they use is_compat_thread().
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
As done in arm, this change makes it easy to confirm we invoke syscall
related hooks, including syscall tracepoint, audit and seccomp which would
be implemented later, in correct order. That is, undoing operations in the
opposite order on exit that they were done on entry.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
If a task gets scheduled out and back in again and nothing has touched
its FPSIMD state in the mean time, there is really no reason to reload
it from memory. Similarly, repeated calls to kernel_neon_begin() and
kernel_neon_end() will preserve and restore the FPSIMD state every time.
This patch defers the FPSIMD state restore to the last possible moment,
i.e., right before the task returns to userland. If a task does not return to
userland at all (for any reason), the existing FPSIMD state is preserved
and may be reused by the owning task if it gets scheduled in again on the
same CPU.
This patch adds two more functions to abstract away from straight FPSIMD
register file saves and restores:
- fpsimd_restore_current_state -> ensure current's FPSIMD state is loaded
- fpsimd_flush_task_state -> invalidate live copies of a task's FPSIMD state
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Commit 8f34a1da35 ("arm64: ptrace: use HW_BREAKPOINT_EMPTY type for
disabled breakpoints") fixed an issue with GDB trying to zero breakpoint
control registers. The problem there is that the arch hw_breakpoint code
will attempt to create a (disabled), execute breakpoint of length 0.
This will fail validation and report unexpected failure to GDB. To avoid
this, we treated disabled breakpoints as HW_BREAKPOINT_EMPTY, but that
seems to have broken with recent kernels, causing watchpoints to be
treated as TYPE_INST in the core code and returning ENOSPC for any
further breakpoints.
This patch fixes the problem by prioritising the `enable' field of the
breakpoint: if it is cleared, we simply update the perf_event_attr to
indicate that the thing is disabled and don't bother changing either the
type or the length. This reinforces the behaviour that the breakpoint
control register is essentially read-only apart from the enable bit
when disabling a breakpoint.
Cc: <stable@vger.kernel.org>
Reported-by: Aaron Liu <liucy214@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
On a BE system the wrong half of the X registers is retrieved/written
when attempting to get/set the value of aarch32 registers through
ptrace.
Ensure that types are the correct width so that the relevant
casting occurs.
Signed-off-by: Matthew Leach <matthew.leach@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The software breakpoint handlers are hooked in directly from ptrace,
which makes it difficult to add additional handlers for things like
kprobes and kgdb.
This patch moves the handling code into debug-monitors.c, where we can
dispatch to different debug subsystems more easily.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Eric W. Biederman