diff options
| author | Liu Shixin <liushixin2@huawei.com> | 2022-12-07 10:50:38 +0800 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-02-02 19:33:05 -0800 |
| commit | cb80242cc679d6397e77d8a964deeb3ff218d2b5 (patch) | |
| tree | ecdf31a5cf547e550ddd92d47b7aa84a37017ee8 /arch/riscv/kernel/stacktrace.c | |
| parent | f0293cd1f4fcc4fbdcd65a5a7b3b318a6d471f78 (diff) | |
riscv: stacktrace: Fix missing the first frame
When running kfence_test, I found some testcases failed like this:
# test_out_of_bounds_read: EXPECTATION FAILED at mm/kfence/kfence_test.c:346
Expected report_matches(&expect) to be true, but is false
not ok 1 - test_out_of_bounds_read
The corresponding call-trace is:
BUG: KFENCE: out-of-bounds read in kunit_try_run_case+0x38/0x84
Out-of-bounds read at 0x(____ptrval____) (32B right of kfence-#10):
kunit_try_run_case+0x38/0x84
kunit_generic_run_threadfn_adapter+0x12/0x1e
kthread+0xc8/0xde
ret_from_exception+0x0/0xc
The kfence_test using the first frame of call trace to check whether the
testcase is succeed or not. Commit 6a00ef449370 ("riscv: eliminate
unreliable __builtin_frame_address(1)") skip first frame for all
case, which results the kfence_test failed. Indeed, we only need to skip
the first frame for case (task==NULL || task==current).
With this patch, the call-trace will be:
BUG: KFENCE: out-of-bounds read in test_out_of_bounds_read+0x88/0x19e
Out-of-bounds read at 0x(____ptrval____) (1B left of kfence-#7):
test_out_of_bounds_read+0x88/0x19e
kunit_try_run_case+0x38/0x84
kunit_generic_run_threadfn_adapter+0x12/0x1e
kthread+0xc8/0xde
ret_from_exception+0x0/0xc
Fixes: 6a00ef449370 ("riscv: eliminate unreliable __builtin_frame_address(1)")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Tested-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20221207025038.1022045-1-liushixin2@huawei.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/kernel/stacktrace.c')
| -rw-r--r-- | arch/riscv/kernel/stacktrace.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c index 75c8dd64fc48..f9a5a7c90ff0 100644 --- a/arch/riscv/kernel/stacktrace.c +++ b/arch/riscv/kernel/stacktrace.c @@ -32,6 +32,7 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs, fp = (unsigned long)__builtin_frame_address(0); sp = current_stack_pointer; pc = (unsigned long)walk_stackframe; + level = -1; } else { /* task blocked in __switch_to */ fp = task->thread.s[0]; @@ -43,7 +44,7 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs, unsigned long low, high; struct stackframe *frame; - if (unlikely(!__kernel_text_address(pc) || (level++ >= 1 && !fn(arg, pc)))) + if (unlikely(!__kernel_text_address(pc) || (level++ >= 0 && !fn(arg, pc)))) break; /* Validate frame pointer */ |