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| author |   Daniel Axtens <dja@axtens.net> | 2021-06-14 22:09:07 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2021-06-17 00:09:11 +1000 |
| commit | b112fb913b5b5705db22efa90ec60f42518934af (patch) | |
| tree | 78ce3f3f8d13289e02ee7fc9782ae210abb361c0 | |
| parent | selftests/powerpc: EBB selftest for MMCR0 control for PMU SPRs in ISA v3.1 (diff) | |
| download | linux-dev-b112fb913b5b5705db22efa90ec60f42518934af.tar.xz linux-dev-b112fb913b5b5705db22efa90ec60f42518934af.zip | |
powerpc: make stack walking KASAN-safe
Make our stack-walking code KASAN-safe by using __no_sanitize_address.
Generic code, arm64, s390 and x86 all make accesses unchecked for similar
sorts of reasons: when unwinding a stack, we might touch memory that KASAN
has marked as being out-of-bounds. In ppc64 KASAN development, I hit this
sometimes when checking for an exception frame - because we're checking
an arbitrary offset into the stack frame.
See commit 20955746320e ("s390/kasan: avoid false positives during stack
unwind"), commit bcaf669b4bdb ("arm64: disable kasan when accessing
frame->fp in unwind_frame"), commit 91e08ab0c851 ("x86/dumpstack:
Prevent KASAN false positive warnings") and commit 6e22c8366416
("tracing, kasan: Silence Kasan warning in check_stack of stack_tracer").
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210614120907.1952321-1-dja@axtens.net
| -rw-r--r-- | arch/powerpc/kernel/process.c | 5 | ||||
| -rw-r--r-- | arch/powerpc/kernel/stacktrace.c | 8 | ||||
| -rw-r--r-- | arch/powerpc/perf/callchain.c | 2 |
3 files changed, 8 insertions, 7 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 3626074acec9..4e593fc2c66d 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -2133,8 +2133,9 @@ unsigned long get_wchan(struct task_struct *p) static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH; -void show_stack(struct task_struct *tsk, unsigned long *stack, - const char *loglvl) +void __no_sanitize_address show_stack(struct task_struct *tsk, + unsigned long *stack, + const char *loglvl) { unsigned long sp, ip, lr, newsp; int count = 0; diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c index 1deb1bf331dd..1961e6d5e33b 100644 --- a/arch/powerpc/kernel/stacktrace.c +++ b/arch/powerpc/kernel/stacktrace.c @@ -23,8 +23,8 @@ #include <asm/paca.h> -void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, - struct task_struct *task, struct pt_regs *regs) +void __no_sanitize_address arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, + struct task_struct *task, struct pt_regs *regs) { unsigned long sp; @@ -61,8 +61,8 @@ void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, * * If the task is not 'current', the caller *must* ensure the task is inactive. */ -int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, - void *cookie, struct task_struct *task) +int __no_sanitize_address arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, + void *cookie, struct task_struct *task) { unsigned long sp; unsigned long newsp; diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c index 6c028ee513c0..082f6d0308a4 100644 --- a/arch/powerpc/perf/callchain.c +++ b/arch/powerpc/perf/callchain.c @@ -40,7 +40,7 @@ static int valid_next_sp(unsigned long sp, unsigned long prev_sp) return 0; } -void +void __no_sanitize_address perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { unsigned long sp, next_sp; |