Messages in this thread Patch in this message | | | From | Björn Töpel <> | Subject | [PATCH 1/2] riscv: Add "Code:" to RISC-V splats | Date | Fri, 13 Jan 2023 15:45:51 +0100 |
| |
From: Björn Töpel <bjorn@rivosinc.com>
Add "Code:" output to RISC-V splats. Mimic x86-64's byte-for-byte dumps.
An example: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Oops [#1] Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.2.0-rc3-00063-g0ce8b1377b2b-dirty #3 Hardware name: riscv-virtio,qemu (DT) epc : kernel_init+0xc8/0x10e ra : kernel_init+0x70/0x10e epc : ffffffff80bd9938 ra : ffffffff80bd98e0 sp : ff2000000060bec0 gp : ffffffff81730b28 tp : ff6000007ff00000 t0 : 7974697275636573 t1 : 0000000000000000 t2 : 3030303270393d6e s0 : ff2000000060bee0 s1 : ffffffff81732028 a0 : 0000000000000000 a1 : ff6000008157e600 a2 : 0000000000000002 a3 : ffffffff8176a470 a4 : 0000000000000000 a5 : 000000000000000a a6 : 0000000000000118 a7 : ff6000008157e600 s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000 s5 : 0000000000000000 s6 : 0000000000000000 s7 : 0000000000000000 s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000000000000000 s11: 0000000000000000 t3 : ffffffff81185ff0 t4 : 0000000000000022 t5 : 000000000000003d t6 : 0000000000000000 status: 0000000200000120 badaddr: 0000000000000000 cause: 000000000000000f [<ffffffff80003528>] ret_from_exception+0x0/0x16 Code: 2a 86 79 d1 8c 60 17 a5 69 00 13 05 65 38 ef d0 2e db a9 47 <1c> c1 17 a5 ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b SMP: stopping secondary CPUs ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---
Signed-off-by: Björn Töpel <bjorn@rivosinc.com> --- arch/riscv/kernel/traps.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 549bde5c970a..efadff4190e0 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -29,6 +29,33 @@ int show_unhandled_signals = 1; static DEFINE_SPINLOCK(die_lock); +static void dump_kernel_instr(const char *loglvl, struct pt_regs *regs) +{ +#define PROLOGUE_SIZE 20 +#define EPILOGUE_SIZE 3 +#define OPCODE_BUFSIZE (PROLOGUE_SIZE + 1 + EPILOGUE_SIZE) + u8 opcodes[OPCODE_BUFSIZE]; + unsigned long prologue = regs->epc - PROLOGUE_SIZE; + + if (user_mode(regs)) + return; + + switch (copy_from_kernel_nofault(opcodes, (u8 *)prologue, sizeof(opcodes))) { + case 0: + printk("%sCode: %" __stringify(PROLOGUE_SIZE) "ph <%02x> %" + __stringify(EPILOGUE_SIZE) "ph\n", loglvl, opcodes, + opcodes[PROLOGUE_SIZE], opcodes + PROLOGUE_SIZE + 1); + break; + case -EPERM: + /* No access to the user space stack of other tasks. Ignore. */ + break; + default: + printk("%sCode: Unable to access opcode bytes at 0x%lx.\n", + loglvl, prologue); + break; + } +} + void die(struct pt_regs *regs, const char *str) { static int die_counter; @@ -43,8 +70,10 @@ void die(struct pt_regs *regs, const char *str) pr_emerg("%s [#%d]\n", str, ++die_counter); print_modules(); - if (regs) + if (regs) { show_regs(regs); + dump_kernel_instr(KERN_EMERG, regs); + } cause = regs ? regs->cause : -1; ret = notify_die(DIE_OOPS, str, regs, 0, cause, SIGSEGV); -- 2.37.2
| |