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author | Guo Ren <guoren@linux.alibaba.com> | 2022-11-09 09:49:37 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-06-16 14:39:47 +0300 |
commit | aae5f57c43a97d11dbf79d24a149f71b00f922ff (patch) | |
tree | 2a2816c04e5927bb431477426a7e57d208c968b5 /arch | |
parent | 42d30da50d5c1ec433fd9551bfddd6887407c352 (diff) | |
download | linux-aae5f57c43a97d11dbf79d24a149f71b00f922ff.tar.xz |
riscv: stacktrace: Make walk_stackframe cross pt_regs frame
[ Upstream commit 7ecdadf7f8c659524f6b2aebf6be7bf619764d90 ]
The current walk_stackframe with FRAME_POINTER would stop unwinding at
ret_from_exception:
BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1518
in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 1, name: init
CPU: 0 PID: 1 Comm: init Not tainted 5.10.113-00021-g15c15974895c-dirty #192
Call Trace:
[<ffffffe0002038c8>] walk_stackframe+0x0/0xee
[<ffffffe000aecf48>] show_stack+0x32/0x4a
[<ffffffe000af1618>] dump_stack_lvl+0x72/0x8e
[<ffffffe000af1648>] dump_stack+0x14/0x1c
[<ffffffe000239ad2>] ___might_sleep+0x12e/0x138
[<ffffffe000239aec>] __might_sleep+0x10/0x18
[<ffffffe000afe3fe>] down_read+0x22/0xa4
[<ffffffe000207588>] do_page_fault+0xb0/0x2fe
[<ffffffe000201b80>] ret_from_exception+0x0/0xc
The optimization would help walk_stackframe cross the pt_regs frame and
get more backtrace of debug info:
BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1518
in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 1, name: init
CPU: 0 PID: 1 Comm: init Not tainted 5.10.113-00021-g15c15974895c-dirty #192
Call Trace:
[<ffffffe0002038c8>] walk_stackframe+0x0/0xee
[<ffffffe000aecf48>] show_stack+0x32/0x4a
[<ffffffe000af1618>] dump_stack_lvl+0x72/0x8e
[<ffffffe000af1648>] dump_stack+0x14/0x1c
[<ffffffe000239ad2>] ___might_sleep+0x12e/0x138
[<ffffffe000239aec>] __might_sleep+0x10/0x18
[<ffffffe000afe3fe>] down_read+0x22/0xa4
[<ffffffe000207588>] do_page_fault+0xb0/0x2fe
[<ffffffe000201b80>] ret_from_exception+0x0/0xc
[<ffffffe000613c06>] riscv_intc_irq+0x1a/0x72
[<ffffffe000201b80>] ret_from_exception+0x0/0xc
[<ffffffe00033f44a>] vma_link+0x54/0x160
[<ffffffe000341d7a>] mmap_region+0x2cc/0x4d0
[<ffffffe000342256>] do_mmap+0x2d8/0x3ac
[<ffffffe000326318>] vm_mmap_pgoff+0x70/0xb8
[<ffffffe00032638a>] vm_mmap+0x2a/0x36
[<ffffffe0003cfdde>] elf_map+0x72/0x84
[<ffffffe0003d05f8>] load_elf_binary+0x69a/0xec8
[<ffffffe000376240>] bprm_execve+0x246/0x53a
[<ffffffe00037786c>] kernel_execve+0xe8/0x124
[<ffffffe000aecdf2>] run_init_process+0xfa/0x10c
[<ffffffe000aece16>] try_to_run_init_process+0x12/0x3c
[<ffffffe000afa920>] kernel_init+0xb4/0xf8
[<ffffffe000201b80>] ret_from_exception+0x0/0xc
Here is the error injection test code for the above output:
drivers/irqchip/irq-riscv-intc.c:
static asmlinkage void riscv_intc_irq(struct pt_regs *regs)
{
unsigned long cause = regs->cause & ~CAUSE_IRQ_FLAG;
+ u32 tmp; __get_user(tmp, (u32 *)0);
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20221109064937.3643993-3-guoren@kernel.org
[Palmer: use SYM_CODE_*]
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Stable-dep-of: a2a4d4a6a0bf ("riscv: stacktrace: fixed walk_stackframe()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/riscv/kernel/entry.S | 3 | ||||
-rw-r--r-- | arch/riscv/kernel/stacktrace.c | 9 |
2 files changed, 11 insertions, 1 deletions
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 5ca2860cc06c..851c967c49cc 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -231,7 +231,7 @@ ret_from_syscall_rejected: andi t0, t0, _TIF_SYSCALL_WORK bnez t0, handle_syscall_trace_exit -ret_from_exception: +SYM_CODE_START_NOALIGN(ret_from_exception) REG_L s0, PT_STATUS(sp) csrc CSR_STATUS, SR_IE #ifdef CONFIG_TRACE_IRQFLAGS @@ -245,6 +245,7 @@ ret_from_exception: andi s0, s0, SR_SPP #endif bnez s0, resume_kernel +SYM_CODE_END(ret_from_exception) resume_userspace: /* Interrupts must be disabled here so flags are checked atomically */ diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c index 894ae66421a7..26f3916eea47 100644 --- a/arch/riscv/kernel/stacktrace.c +++ b/arch/riscv/kernel/stacktrace.c @@ -18,6 +18,8 @@ register unsigned long sp_in_global __asm__("sp"); #ifdef CONFIG_FRAME_POINTER +extern asmlinkage void ret_from_exception(void); + void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs, bool (*fn)(void *, unsigned long), void *arg) { @@ -62,6 +64,13 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs, fp = frame->fp; pc = ftrace_graph_ret_addr(current, NULL, frame->ra, &frame->ra); + if (pc == (unsigned long)ret_from_exception) { + if (unlikely(!__kernel_text_address(pc) || !fn(arg, pc))) + break; + + pc = ((struct pt_regs *)sp)->epc; + fp = ((struct pt_regs *)sp)->s0; + } } } |