* [PATCH 1/2] riscv: stacktrace: Fixup ftrace_graph_ret_addr retp argument
2022-11-09 6:49 [PATCH 0/2] riscv: stacktrace: A fixup and an optimization guoren
@ 2022-11-09 6:49 ` guoren
2022-11-09 6:49 ` [PATCH 2/2] riscv: stacktrace: Make walk_stackframe cross pt_regs frame guoren
` (2 subsequent siblings)
3 siblings, 0 replies; 9+ messages in thread
From: guoren @ 2022-11-09 6:49 UTC (permalink / raw)
To: anup, paul.walmsley, palmer, conor.dooley, heiko, peterz, arnd,
linux-arch, keescook, paulmck, frederic, nsaenzju, changbin.du,
vincent.chen
Cc: linux-riscv, linux-kernel, Guo Ren, Guo Ren, Alan Kao,
Palmer Dabbelt
From: Guo Ren <guoren@linux.alibaba.com>
The 'retp' is a pointer to the return address on the stack, so we
must pass the current return address pointer as the 'retp'
argument to ftrace_push_return_trace(). Not parent function's
return address on the stack.
Fixes: b785ec129bd9 ("riscv/ftrace: Add HAVE_FUNCTION_GRAPH_RET_ADDR_PTR support")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Alan Kao <alankao@andestech.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
---
arch/riscv/kernel/stacktrace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
index 08d11a53f39e..bcfe9eb55f80 100644
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -58,7 +58,7 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
} else {
fp = frame->fp;
pc = ftrace_graph_ret_addr(current, NULL, frame->ra,
- (unsigned long *)(fp - 8));
+ &frame->ra);
}
}
--
2.36.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH 2/2] riscv: stacktrace: Make walk_stackframe cross pt_regs frame
2022-11-09 6:49 [PATCH 0/2] riscv: stacktrace: A fixup and an optimization guoren
2022-11-09 6:49 ` [PATCH 1/2] riscv: stacktrace: Fixup ftrace_graph_ret_addr retp argument guoren
@ 2022-11-09 6:49 ` guoren
2022-11-21 9:53 ` Guo Ren
2022-12-06 2:59 ` Palmer Dabbelt
2022-12-06 2:59 ` [PATCH 0/2] riscv: stacktrace: A fixup and an optimization Palmer Dabbelt
2022-12-06 3:10 ` patchwork-bot+linux-riscv
3 siblings, 2 replies; 9+ messages in thread
From: guoren @ 2022-11-09 6:49 UTC (permalink / raw)
To: anup, paul.walmsley, palmer, conor.dooley, heiko, peterz, arnd,
linux-arch, keescook, paulmck, frederic, nsaenzju, changbin.du,
vincent.chen
Cc: linux-riscv, linux-kernel, Guo Ren, Guo Ren, Palmer Dabbelt
From: Guo Ren <guoren@linux.alibaba.com>
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>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Changbin Du <changbin.du@intel.com>
---
arch/riscv/kernel/entry.S | 2 +-
arch/riscv/kernel/stacktrace.c | 9 +++++++++
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index b9eda3fcbd6d..329cf51fcd4d 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -248,7 +248,7 @@ ret_from_syscall_rejected:
andi t0, t0, _TIF_SYSCALL_WORK
bnez t0, handle_syscall_trace_exit
-ret_from_exception:
+ENTRY(ret_from_exception)
REG_L s0, PT_STATUS(sp)
csrc CSR_STATUS, SR_IE
#ifdef CONFIG_TRACE_IRQFLAGS
diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
index bcfe9eb55f80..75c8dd64fc48 100644
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -16,6 +16,8 @@
#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)
{
@@ -59,6 +61,13 @@ 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;
+ }
}
}
--
2.36.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH 2/2] riscv: stacktrace: Make walk_stackframe cross pt_regs frame
2022-11-09 6:49 ` [PATCH 2/2] riscv: stacktrace: Make walk_stackframe cross pt_regs frame guoren
@ 2022-11-21 9:53 ` Guo Ren
2022-11-21 11:49 ` Guo Ren
2022-12-06 2:59 ` Palmer Dabbelt
1 sibling, 1 reply; 9+ messages in thread
From: Guo Ren @ 2022-11-21 9:53 UTC (permalink / raw)
To: anup, paul.walmsley, palmer, conor.dooley, heiko, peterz, arnd,
linux-arch, keescook, paulmck, frederic, nsaenzju, changbin.du,
vincent.chen
Cc: linux-riscv, linux-kernel, Guo Ren, Palmer Dabbelt
On Wed, Nov 9, 2022 at 2:50 PM <guoren@kernel.org> wrote:
>
> From: Guo Ren <guoren@linux.alibaba.com>
>
> 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>
> Cc: Palmer Dabbelt <palmer@rivosinc.com>
> Cc: Changbin Du <changbin.du@intel.com>
> ---
> arch/riscv/kernel/entry.S | 2 +-
> arch/riscv/kernel/stacktrace.c | 9 +++++++++
> 2 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
> index b9eda3fcbd6d..329cf51fcd4d 100644
> --- a/arch/riscv/kernel/entry.S
> +++ b/arch/riscv/kernel/entry.S
> @@ -248,7 +248,7 @@ ret_from_syscall_rejected:
> andi t0, t0, _TIF_SYSCALL_WORK
> bnez t0, handle_syscall_trace_exit
>
> -ret_from_exception:
> +ENTRY(ret_from_exception)
> REG_L s0, PT_STATUS(sp)
> csrc CSR_STATUS, SR_IE
> #ifdef CONFIG_TRACE_IRQFLAGS
> diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
> index bcfe9eb55f80..75c8dd64fc48 100644
> --- a/arch/riscv/kernel/stacktrace.c
> +++ b/arch/riscv/kernel/stacktrace.c
> @@ -16,6 +16,8 @@
>
> #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)
> {
> @@ -59,6 +61,13 @@ 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) {
I forgot ret_from_syscall because I tested it on the generic_entry
series base. I would merge this patch into the generic_entry series as
an optimization.
> + if (unlikely(!__kernel_text_address(pc) || !fn(arg, pc)))
> + break;
> +
> + pc = ((struct pt_regs *)sp)->epc;
> + fp = ((struct pt_regs *)sp)->s0;
> + }
> }
>
> }
> --
> 2.36.1
>
--
Best Regards
Guo Ren
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH 2/2] riscv: stacktrace: Make walk_stackframe cross pt_regs frame
2022-11-21 9:53 ` Guo Ren
@ 2022-11-21 11:49 ` Guo Ren
0 siblings, 0 replies; 9+ messages in thread
From: Guo Ren @ 2022-11-21 11:49 UTC (permalink / raw)
To: anup, paul.walmsley, palmer, conor.dooley, heiko, peterz, arnd,
linux-arch, keescook, paulmck, frederic, nsaenzju, changbin.du,
vincent.chen
Cc: linux-riscv, linux-kernel, Guo Ren, Palmer Dabbelt
On Mon, Nov 21, 2022 at 5:53 PM Guo Ren <guoren@kernel.org> wrote:
>
> On Wed, Nov 9, 2022 at 2:50 PM <guoren@kernel.org> wrote:
> >
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > 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>
> > Cc: Palmer Dabbelt <palmer@rivosinc.com>
> > Cc: Changbin Du <changbin.du@intel.com>
> > ---
> > arch/riscv/kernel/entry.S | 2 +-
> > arch/riscv/kernel/stacktrace.c | 9 +++++++++
> > 2 files changed, 10 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
> > index b9eda3fcbd6d..329cf51fcd4d 100644
> > --- a/arch/riscv/kernel/entry.S
> > +++ b/arch/riscv/kernel/entry.S
> > @@ -248,7 +248,7 @@ ret_from_syscall_rejected:
> > andi t0, t0, _TIF_SYSCALL_WORK
> > bnez t0, handle_syscall_trace_exit
> >
> > -ret_from_exception:
> > +ENTRY(ret_from_exception)
> > REG_L s0, PT_STATUS(sp)
> > csrc CSR_STATUS, SR_IE
> > #ifdef CONFIG_TRACE_IRQFLAGS
> > diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
> > index bcfe9eb55f80..75c8dd64fc48 100644
> > --- a/arch/riscv/kernel/stacktrace.c
> > +++ b/arch/riscv/kernel/stacktrace.c
> > @@ -16,6 +16,8 @@
> >
> > #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)
> > {
> > @@ -59,6 +61,13 @@ 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) {
> I forgot ret_from_syscall because I tested it on the generic_entry
> series base. I would merge this patch into the generic_entry series as
> an optimization.
No, the patch is correct. The ret_from_syscall is unnecessary because
it's from user space.
>
> > + if (unlikely(!__kernel_text_address(pc) || !fn(arg, pc)))
> > + break;
> > +
> > + pc = ((struct pt_regs *)sp)->epc;
> > + fp = ((struct pt_regs *)sp)->s0;
> > + }
> > }
> >
> > }
> > --
> > 2.36.1
> >
>
>
> --
> Best Regards
> Guo Ren
--
Best Regards
Guo Ren
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 2/2] riscv: stacktrace: Make walk_stackframe cross pt_regs frame
2022-11-09 6:49 ` [PATCH 2/2] riscv: stacktrace: Make walk_stackframe cross pt_regs frame guoren
2022-11-21 9:53 ` Guo Ren
@ 2022-12-06 2:59 ` Palmer Dabbelt
2022-12-06 3:30 ` Guo Ren
1 sibling, 1 reply; 9+ messages in thread
From: Palmer Dabbelt @ 2022-12-06 2:59 UTC (permalink / raw)
To: guoren
Cc: anup, Paul Walmsley, Conor Dooley, heiko, peterz, Arnd Bergmann,
linux-arch, keescook, paulmck, frederic, nsaenzju, changbin.du,
vincent.chen, linux-riscv, linux-kernel, guoren, guoren
On Tue, 08 Nov 2022 22:49:37 PST (-0800), guoren@kernel.org wrote:
> From: Guo Ren <guoren@linux.alibaba.com>
>
> 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>
> Cc: Palmer Dabbelt <palmer@rivosinc.com>
> Cc: Changbin Du <changbin.du@intel.com>
> ---
> arch/riscv/kernel/entry.S | 2 +-
> arch/riscv/kernel/stacktrace.c | 9 +++++++++
> 2 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
> index b9eda3fcbd6d..329cf51fcd4d 100644
> --- a/arch/riscv/kernel/entry.S
> +++ b/arch/riscv/kernel/entry.S
> @@ -248,7 +248,7 @@ ret_from_syscall_rejected:
> andi t0, t0, _TIF_SYSCALL_WORK
> bnez t0, handle_syscall_trace_exit
>
> -ret_from_exception:
> +ENTRY(ret_from_exception)
This at least needs an END(), but it should also be converted over to
some non-function entry flavor. I converted it over to
SYM_CODE_START_NOALIGN(), with the cooresponding SYM_CODE_END(), and put
it on for-next.
> REG_L s0, PT_STATUS(sp)
> csrc CSR_STATUS, SR_IE
> #ifdef CONFIG_TRACE_IRQFLAGS
> diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
> index bcfe9eb55f80..75c8dd64fc48 100644
> --- a/arch/riscv/kernel/stacktrace.c
> +++ b/arch/riscv/kernel/stacktrace.c
> @@ -16,6 +16,8 @@
>
> #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)
> {
> @@ -59,6 +61,13 @@ 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;
> + }
> }
>
> }
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^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH 2/2] riscv: stacktrace: Make walk_stackframe cross pt_regs frame
2022-12-06 2:59 ` Palmer Dabbelt
@ 2022-12-06 3:30 ` Guo Ren
0 siblings, 0 replies; 9+ messages in thread
From: Guo Ren @ 2022-12-06 3:30 UTC (permalink / raw)
To: Palmer Dabbelt
Cc: anup, Paul Walmsley, Conor Dooley, heiko, peterz, Arnd Bergmann,
linux-arch, keescook, paulmck, frederic, nsaenzju, changbin.du,
vincent.chen, linux-riscv, linux-kernel, guoren
On Tue, Dec 6, 2022 at 10:59 AM Palmer Dabbelt <palmer@dabbelt.com> wrote:
>
> On Tue, 08 Nov 2022 22:49:37 PST (-0800), guoren@kernel.org wrote:
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > 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>
> > Cc: Palmer Dabbelt <palmer@rivosinc.com>
> > Cc: Changbin Du <changbin.du@intel.com>
> > ---
> > arch/riscv/kernel/entry.S | 2 +-
> > arch/riscv/kernel/stacktrace.c | 9 +++++++++
> > 2 files changed, 10 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
> > index b9eda3fcbd6d..329cf51fcd4d 100644
> > --- a/arch/riscv/kernel/entry.S
> > +++ b/arch/riscv/kernel/entry.S
> > @@ -248,7 +248,7 @@ ret_from_syscall_rejected:
> > andi t0, t0, _TIF_SYSCALL_WORK
> > bnez t0, handle_syscall_trace_exit
> >
> > -ret_from_exception:
> > +ENTRY(ret_from_exception)
>
> This at least needs an END(), but it should also be converted over to
Yes, I missed END() here.
> some non-function entry flavor. I converted it over to
> SYM_CODE_START_NOALIGN(), with the cooresponding SYM_CODE_END(), and put
> it on for-next.
Is that also for ret_from_fork & __switch_to?
>
> > REG_L s0, PT_STATUS(sp)
> > csrc CSR_STATUS, SR_IE
> > #ifdef CONFIG_TRACE_IRQFLAGS
> > diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
> > index bcfe9eb55f80..75c8dd64fc48 100644
> > --- a/arch/riscv/kernel/stacktrace.c
> > +++ b/arch/riscv/kernel/stacktrace.c
> > @@ -16,6 +16,8 @@
> >
> > #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)
> > {
> > @@ -59,6 +61,13 @@ 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;
> > + }
> > }
> >
> > }
--
Best Regards
Guo Ren
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^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 0/2] riscv: stacktrace: A fixup and an optimization
2022-11-09 6:49 [PATCH 0/2] riscv: stacktrace: A fixup and an optimization guoren
2022-11-09 6:49 ` [PATCH 1/2] riscv: stacktrace: Fixup ftrace_graph_ret_addr retp argument guoren
2022-11-09 6:49 ` [PATCH 2/2] riscv: stacktrace: Make walk_stackframe cross pt_regs frame guoren
@ 2022-12-06 2:59 ` Palmer Dabbelt
2022-12-06 3:10 ` patchwork-bot+linux-riscv
3 siblings, 0 replies; 9+ messages in thread
From: Palmer Dabbelt @ 2022-12-06 2:59 UTC (permalink / raw)
To: paulmck, Paul Walmsley, Arnd Bergmann, anup, keescook, frederic,
nsaenzju, peterz, heiko, Conor Dooley, vincent.chen, changbin.du,
Palmer Dabbelt, guoren, linux-arch
Cc: linux-riscv, Guo Ren, linux-kernel
On Wed, 9 Nov 2022 01:49:35 -0500, guoren@kernel.org wrote:
> From: Guo Ren <guoren@linux.alibaba.com>
>
> First is a fixup for the return address pointer. The second makes
> walk_stackframe could cross the pt_regs frame.
>
> Guo Ren (2):
> riscv: stacktrace: Fixup ftrace_graph_ret_addr retp argument
> riscv: stacktrace: Make walk_stackframe cross pt_regs frame
>
> [...]
Applied, thanks!
[1/2] riscv: stacktrace: Fixup ftrace_graph_ret_addr retp argument
https://git.kernel.org/palmer/c/5c3022e4a616
[2/2] riscv: stacktrace: Make walk_stackframe cross pt_regs frame
https://git.kernel.org/palmer/c/7ecdadf7f8c6
Best regards,
--
Palmer Dabbelt <palmer@rivosinc.com>
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^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH 0/2] riscv: stacktrace: A fixup and an optimization
2022-11-09 6:49 [PATCH 0/2] riscv: stacktrace: A fixup and an optimization guoren
` (2 preceding siblings ...)
2022-12-06 2:59 ` [PATCH 0/2] riscv: stacktrace: A fixup and an optimization Palmer Dabbelt
@ 2022-12-06 3:10 ` patchwork-bot+linux-riscv
3 siblings, 0 replies; 9+ messages in thread
From: patchwork-bot+linux-riscv @ 2022-12-06 3:10 UTC (permalink / raw)
To: Guo Ren
Cc: linux-riscv, anup, paul.walmsley, palmer, conor.dooley, heiko,
peterz, arnd, linux-arch, keescook, paulmck, frederic, nsaenzju,
changbin.du, vincent.chen, linux-kernel, guoren
Hello:
This series was applied to riscv/linux.git (for-next)
by Palmer Dabbelt <palmer@rivosinc.com>:
On Wed, 9 Nov 2022 01:49:35 -0500 you wrote:
> From: Guo Ren <guoren@linux.alibaba.com>
>
> First is a fixup for the return address pointer. The second makes
> walk_stackframe could cross the pt_regs frame.
>
> Guo Ren (2):
> riscv: stacktrace: Fixup ftrace_graph_ret_addr retp argument
> riscv: stacktrace: Make walk_stackframe cross pt_regs frame
>
> [...]
Here is the summary with links:
- [1/2] riscv: stacktrace: Fixup ftrace_graph_ret_addr retp argument
https://git.kernel.org/riscv/c/5c3022e4a616
- [2/2] riscv: stacktrace: Make walk_stackframe cross pt_regs frame
https://git.kernel.org/riscv/c/7ecdadf7f8c6
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
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^ permalink raw reply [flat|nested] 9+ messages in thread