From 73bcd7e06ae6269e9889a530a32c3473c00728e2 Mon Sep 17 00:00:00 2001 From: Yunhui Cui Date: Tue, 12 Sep 2023 10:13:49 +0800 Subject: [PATCH] riscv: add userland instruction dump to RISC-V splats MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Björn Töpel Signed-off-by: Björn Töpel --- arch/riscv/kernel/traps.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 19807c4d3805d4..37c0fa76e34b68 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -34,7 +34,21 @@ 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); @@ -43,7 +57,7 @@ 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 { @@ -72,7 +86,7 @@ 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; @@ -105,6 +119,7 @@ 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);