riscv: stacktrace: Make walk_stackframe cross pt_regs frame
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>