diff mbox series

[v6] riscv: add userland instruction dump to RISC-V splats

Message ID 20230912021349.28302-1-cuiyunhui@bytedance.com
State New
Headers
Series [v6] riscv: add userland instruction dump to RISC-V splats |

Commit Message

yunhui cui Sept. 12, 2023, 2:13 a.m. UTC 
  Add userland instruction dump and rename dump_kernel_instr()
to dump_instr().

An example:
[    0.822439] Freeing unused kernel image (initmem) memory: 6916K
[    0.823817] Run /init as init process
[    0.839411] init[1]: unhandled signal 4 code 0x1 at 0x000000000005be18 in bb[10000+5fb000]
[    0.840751] CPU: 0 PID: 1 Comm: init Not tainted 5.14.0-rc4-00049-gbd644290aa72-dirty #187
[    0.841373] Hardware name:  , BIOS
[    0.841743] epc : 000000000005be18 ra : 0000000000079e74 sp : 0000003fffcafda0
[    0.842271]  gp : ffffffff816e9dc8 tp : 0000000000000000 t0 : 0000000000000000
[    0.842947]  t1 : 0000003fffc9fdf0 t2 : 0000000000000000 s0 : 0000000000000000
[    0.843434]  s1 : 0000000000000000 a0 : 0000003fffca0190 a1 : 0000003fffcafe18
[    0.843891]  a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000
[    0.844357]  a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000000000
[    0.844803]  s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000
[    0.845253]  s5 : 0000000000000000 s6 : 0000000000000000 s7 : 0000000000000000
[    0.845722]  s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000000000000000
[    0.846180]  s11: 0000000000d144e0 t3 : 0000000000000000 t4 : 0000000000000000
[    0.846616]  t5 : 0000000000000000 t6 : 0000000000000000
[    0.847204] status: 0000000200000020 badaddr: 00000000f0028053 cause: 0000000000000002
[    0.848219] Code: f06f ff5f 3823 fa11 0113 fb01 2e23 0201 0293 0000 (8053) f002
[    0.851016] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004

Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
---
 arch/riscv/kernel/traps.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

Comments

yunhui cui Oct. 11, 2023, 3:23 a.m. UTC | #1 
Hi Björn,

On Tue, Sep 12, 2023 at 8:13 PM Björn Töpel <bjorn@kernel.org> wrote:
>
> Yunhui Cui <cuiyunhui@bytedance.com> writes:
>
> > Add userland instruction dump and rename dump_kernel_instr()
> > to dump_instr().
> >
> > An example:
> > [    0.822439] Freeing unused kernel image (initmem) memory: 6916K
> > [    0.823817] Run /init as init process
> > [    0.839411] init[1]: unhandled signal 4 code 0x1 at 0x000000000005be18 in bb[10000+5fb000]
> > [    0.840751] CPU: 0 PID: 1 Comm: init Not tainted 5.14.0-rc4-00049-gbd644290aa72-dirty #187
> > [    0.841373] Hardware name:  , BIOS
> > [    0.841743] epc : 000000000005be18 ra : 0000000000079e74 sp : 0000003fffcafda0
> > [    0.842271]  gp : ffffffff816e9dc8 tp : 0000000000000000 t0 : 0000000000000000
> > [    0.842947]  t1 : 0000003fffc9fdf0 t2 : 0000000000000000 s0 : 0000000000000000
> > [    0.843434]  s1 : 0000000000000000 a0 : 0000003fffca0190 a1 : 0000003fffcafe18
> > [    0.843891]  a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000
> > [    0.844357]  a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000000000
> > [    0.844803]  s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000
> > [    0.845253]  s5 : 0000000000000000 s6 : 0000000000000000 s7 : 0000000000000000
> > [    0.845722]  s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000000000000000
> > [    0.846180]  s11: 0000000000d144e0 t3 : 0000000000000000 t4 : 0000000000000000
> > [    0.846616]  t5 : 0000000000000000 t6 : 0000000000000000
> > [    0.847204] status: 0000000200000020 badaddr: 00000000f0028053 cause: 0000000000000002
> > [    0.848219] Code: f06f ff5f 3823 fa11 0113 fb01 2e23 0201 0293 0000 (8053) f002
> > [    0.851016] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
> >
> > Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
>
> Reviewed-by: Björn Töpel <bjorn@rivosinc.com>

Could u help to merge this patch into linux-next? Or can anyone help
to merge it?

Thanks，
Yunhui
Björn Töpel Oct. 11, 2023, 1:20 p.m. UTC | #2 
yunhui cui <cuiyunhui@bytedance.com> writes:

> Hi Björn,
>
> On Tue, Sep 12, 2023 at 8:13 PM Björn Töpel <bjorn@kernel.org> wrote:
>>
>> Yunhui Cui <cuiyunhui@bytedance.com> writes:
>>
>> > Add userland instruction dump and rename dump_kernel_instr()
>> > to dump_instr().
>> >
>> > An example:
>> > [    0.822439] Freeing unused kernel image (initmem) memory: 6916K
>> > [    0.823817] Run /init as init process
>> > [    0.839411] init[1]: unhandled signal 4 code 0x1 at 0x000000000005be18 in bb[10000+5fb000]
>> > [    0.840751] CPU: 0 PID: 1 Comm: init Not tainted 5.14.0-rc4-00049-gbd644290aa72-dirty #187
>> > [    0.841373] Hardware name:  , BIOS
>> > [    0.841743] epc : 000000000005be18 ra : 0000000000079e74 sp : 0000003fffcafda0
>> > [    0.842271]  gp : ffffffff816e9dc8 tp : 0000000000000000 t0 : 0000000000000000
>> > [    0.842947]  t1 : 0000003fffc9fdf0 t2 : 0000000000000000 s0 : 0000000000000000
>> > [    0.843434]  s1 : 0000000000000000 a0 : 0000003fffca0190 a1 : 0000003fffcafe18
>> > [    0.843891]  a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000
>> > [    0.844357]  a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000000000
>> > [    0.844803]  s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000
>> > [    0.845253]  s5 : 0000000000000000 s6 : 0000000000000000 s7 : 0000000000000000
>> > [    0.845722]  s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000000000000000
>> > [    0.846180]  s11: 0000000000d144e0 t3 : 0000000000000000 t4 : 0000000000000000
>> > [    0.846616]  t5 : 0000000000000000 t6 : 0000000000000000
>> > [    0.847204] status: 0000000200000020 badaddr: 00000000f0028053 cause: 0000000000000002
>> > [    0.848219] Code: f06f ff5f 3823 fa11 0113 fb01 2e23 0201 0293 0000 (8053) f002
>> > [    0.851016] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
>> >
>> > Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
>>
>> Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
>
> Could u help to merge this patch into linux-next? Or can anyone help
> to merge it?

Hey Yunhui,

The next merge-window opens soon, so I'd guess it'll be picked up then!


Cheers,
Björn
patchwork-bot+linux-riscv@kernel.org Nov. 6, 2023, 3 p.m. UTC | #3 
Hello:

This patch was applied to riscv/linux.git (for-next)
by Palmer Dabbelt <palmer@rivosinc.com>:

On Tue, 12 Sep 2023 10:13:49 +0800 you wrote:
> Add userland instruction dump and rename dump_kernel_instr()
> to dump_instr().
> 
> An example:
> [    0.822439] Freeing unused kernel image (initmem) memory: 6916K
> [    0.823817] Run /init as init process
> [    0.839411] init[1]: unhandled signal 4 code 0x1 at 0x000000000005be18 in bb[10000+5fb000]
> [    0.840751] CPU: 0 PID: 1 Comm: init Not tainted 5.14.0-rc4-00049-gbd644290aa72-dirty #187
> [    0.841373] Hardware name:  , BIOS
> [    0.841743] epc : 000000000005be18 ra : 0000000000079e74 sp : 0000003fffcafda0
> [    0.842271]  gp : ffffffff816e9dc8 tp : 0000000000000000 t0 : 0000000000000000
> [    0.842947]  t1 : 0000003fffc9fdf0 t2 : 0000000000000000 s0 : 0000000000000000
> [    0.843434]  s1 : 0000000000000000 a0 : 0000003fffca0190 a1 : 0000003fffcafe18
> [    0.843891]  a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000
> [    0.844357]  a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000000000
> [    0.844803]  s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000
> [    0.845253]  s5 : 0000000000000000 s6 : 0000000000000000 s7 : 0000000000000000
> [    0.845722]  s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000000000000000
> [    0.846180]  s11: 0000000000d144e0 t3 : 0000000000000000 t4 : 0000000000000000
> [    0.846616]  t5 : 0000000000000000 t6 : 0000000000000000
> [    0.847204] status: 0000000200000020 badaddr: 00000000f0028053 cause: 0000000000000002
> [    0.848219] Code: f06f ff5f 3823 fa11 0113 fb01 2e23 0201 0293 0000 (8053) f002
> [    0.851016] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
> 
> [...]

Here is the summary with links:
  - [v6] riscv: add userland instruction dump to RISC-V splats
    https://git.kernel.org/riscv/c/b8a03a634129

You are awesome, thank you!
diff mbox series

Patch

diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index f798c853bede..bd2e8fa25c43 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -33,7 +33,21 @@  int show_unhandled_signals = 1;
 
 static DEFINE_SPINLOCK(die_lock);
 
-static void dump_kernel_instr(const char *loglvl, struct pt_regs *regs)
+static int copy_code(struct pt_regs *regs, u16 *val, const u16 *insns)
+{
+	const void __user *uaddr = (__force const void __user *)insns;
+
+	if (!user_mode(regs))
+		return get_kernel_nofault(*val, insns);
+
+	/* The user space code from other tasks cannot be accessed. */
+	if (regs != task_pt_regs(current))
+		return -EPERM;
+
+	return copy_from_user_nofault(val, uaddr, sizeof(*val));
+}
+
+static void dump_instr(const char *loglvl, struct pt_regs *regs)
 {
 	char str[sizeof("0000 ") * 12 + 2 + 1], *p = str;
 	const u16 *insns = (u16 *)instruction_pointer(regs);
@@ -42,7 +56,7 @@  static void dump_kernel_instr(const char *loglvl, struct pt_regs *regs)
 	int i;
 
 	for (i = -10; i < 2; i++) {
-		bad = get_kernel_nofault(val, &insns[i]);
+		bad = copy_code(regs, &val, &insns[i]);
 		if (!bad) {
 			p += sprintf(p, i == 0 ? "(%04hx) " : "%04hx ", val);
 		} else {
@@ -71,7 +85,7 @@  void die(struct pt_regs *regs, const char *str)
 	print_modules();
 	if (regs) {
 		show_regs(regs);
-		dump_kernel_instr(KERN_EMERG, regs);
+		dump_instr(KERN_EMERG, regs);
 	}
 
 	cause = regs ? regs->cause : -1;
@@ -104,6 +118,7 @@  void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr)
 		print_vma_addr(KERN_CONT " in ", instruction_pointer(regs));
 		pr_cont("\n");
 		__show_regs(regs);
+		dump_instr(KERN_EMERG, regs);
 	}
 
 	force_sig_fault(signo, code, (void __user *)addr);