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x86/dumpstack: Unify show_regs()

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The 32-bit version uses KERN_EMERG and commit

  b0f4c4b32c ("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 <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Link: https://lkml.kernel.org/r/20180306094920.16917-4-bp@alien8.de
This commit is contained in:
Borislav Petkov 2018-03-06 10:49:14 +01:00 committed by Thomas Gleixner
parent 9558080935
commit 16d1cb0bc4
4 changed files with 48 additions and 87 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/include/asm/stacktrace.h
View File

@ -87,8 +87,6 @@ get_stack_pointer(struct task_struct *task, struct pt_regs *regs)
void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
unsigned long *stack, char *log_lvl);
extern unsigned int code_bytes;
/* The form of the top of the frame on the stack */
struct stack_frame {
struct stack_frame *next_frame;

49
arch/x86/kernel/dumpstack.c
View File

@ -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");
}

42
arch/x86/kernel/dumpstack_32.c
View File

@ -127,45 +127,3 @@ unknown:
info->type = STACK_TYPE_UNKNOWN;
return -EINVAL;
}
void show_regs(struct pt_regs *regs)
{
int i;
show_regs_print_info(KERN_EMERG);
__show_regs(regs, !user_mode(regs));
/*
* 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_EMERG);
pr_emerg("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 EIP value.");
break;
}
if (ip == (u8 *)regs->ip)
pr_cont(" <%02x>", c);
else
pr_cont(" %02x", c);
}
}
pr_cont("\n");
}

42
arch/x86/kernel/dumpstack_64.c
View File

@ -149,45 +149,3 @@ unknown:
info->type = STACK_TYPE_UNKNOWN;
return -EINVAL;
}
void show_regs(struct pt_regs *regs)
{
int i;
show_regs_print_info(KERN_DEFAULT);
__show_regs(regs, 1);
/*
* 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");
}