From 16d1cb0bc43642a4d934631a73c5210ad2499e2f Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Tue, 6 Mar 2018 10:49:14 +0100 Subject: x86/dumpstack: Unify show_regs() The 32-bit version uses KERN_EMERG and commit b0f4c4b32c8e ("bugs, x86: Fix printk levels for panic, softlockups and stack dumps") changed the 64-bit version to KERN_DEFAULT. The same justification in that commit that those messages do not belong in the terminal, holds true for 32-bit also, so make it so. Make code_bytes static, while at it. Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Andy Lutomirski Link: https://lkml.kernel.org/r/20180306094920.16917-4-bp@alien8.de --- arch/x86/kernel/dumpstack.c | 49 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 48 insertions(+), 1 deletion(-) (limited to 'arch/x86/kernel/dumpstack.c') diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index a2d8a3908670..18fa9d74c182 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -24,7 +24,7 @@ int panic_on_unrecovered_nmi; int panic_on_io_nmi; -unsigned int code_bytes = 64; +static unsigned int code_bytes = 64; static int die_counter; bool in_task_stack(unsigned long *stack, struct task_struct *task, @@ -375,3 +375,50 @@ static int __init code_bytes_setup(char *s) return 1; } __setup("code_bytes=", code_bytes_setup); + +void show_regs(struct pt_regs *regs) +{ + bool all = true; + int i; + + show_regs_print_info(KERN_DEFAULT); + + if (IS_ENABLED(CONFIG_X86_32)) + all = !user_mode(regs); + + __show_regs(regs, all); + + /* + * When in-kernel, we also print out the stack and code at the + * time of the fault.. + */ + if (!user_mode(regs)) { + unsigned int code_prologue = code_bytes * 43 / 64; + unsigned int code_len = code_bytes; + unsigned char c; + u8 *ip; + + show_trace_log_lvl(current, regs, NULL, KERN_DEFAULT); + + printk(KERN_DEFAULT "Code: "); + + ip = (u8 *)regs->ip - code_prologue; + if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) { + /* try starting at IP */ + ip = (u8 *)regs->ip; + code_len = code_len - code_prologue + 1; + } + for (i = 0; i < code_len; i++, ip++) { + if (ip < (u8 *)PAGE_OFFSET || + probe_kernel_address(ip, c)) { + pr_cont(" Bad RIP value."); + break; + } + if (ip == (u8 *)regs->ip) + pr_cont("<%02x> ", c); + else + pr_cont("%02x ", c); + } + } + pr_cont("\n"); +} -- cgit v1.2.3