From eb165bfa8eafc3d306e34b238e53aafb35dce102 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Thu, 19 Jan 2023 08:47:37 +0100 Subject: [PATCH] riscv: Add instruction dump to RISC-V splats MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add instruction dump (Code:) output to RISC-V splats. Dump 16b parcels. An example: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Oops [#1] Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.2.0-rc3-00302-g840ff44c571d-dirty #27 Hardware name: riscv-virtio,qemu (DT) epc : kernel_init+0xc8/0x10e ra : kernel_init+0x70/0x10e epc : ffffffff80bd9a40 ra : ffffffff80bd99e8 sp : ff2000000060bec0 gp : ffffffff81730b28 tp : ff6000007ff00000 t0 : 7974697275636573 t1 : 0000000000000000 t2 : 3030303270393d6e s0 : ff2000000060bee0 s1 : ffffffff81732028 a0 : 0000000000000000 a1 : ff60000080dd1780 a2 : 0000000000000002 a3 : ffffffff8176a470 a4 : 0000000000000000 a5 : 000000000000000a a6 : 0000000000000081 a7 : ff60000080dd1780 s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000 s5 : 0000000000000000 s6 : 0000000000000000 s7 : 0000000000000000 s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000000000000000 s11: 0000000000000000 t3 : ffffffff81186018 t4 : 0000000000000022 t5 : 000000000000003d t6 : 0000000000000000 status: 0000000200000120 badaddr: 0000000000000000 cause: 000000000000000f [] ret_from_exception+0x0/0x16 Code: 862a d179 608c a517 0069 0513 2be5 d0ef db2e 47a9 (c11c) a517 ---[ 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 Link: https://lore.kernel.org/r/20230119074738.708301-2-bjorn@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/traps.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 549bde5..fbdcdbc 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -29,6 +29,27 @@ int show_unhandled_signals = 1; static DEFINE_SPINLOCK(die_lock); +static void dump_kernel_instr(const char *loglvl, struct pt_regs *regs) +{ + char str[sizeof("0000 ") * 12 + 2 + 1], *p = str; + const u16 *insns = (u16 *)instruction_pointer(regs); + long bad; + u16 val; + int i; + + for (i = -10; i < 2; i++) { + bad = get_kernel_nofault(val, &insns[i]); + if (!bad) { + p += sprintf(p, i == 0 ? "(%04hx) " : "%04hx ", val); + } else { + printk("%sCode: Unable to access instruction at 0x%px.\n", + loglvl, &insns[i]); + return; + } + } + printk("%sCode: %s\n", loglvl, str); +} + void die(struct pt_regs *regs, const char *str) { static int die_counter; @@ -43,8 +64,10 @@ 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); -- 2.7.4