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Commit 16d1cb0b authored by Borislav Petkov's avatar Borislav Petkov Committed by Thomas Gleixner
Browse files

x86/dumpstack: Unify show_regs() 



The 32-bit version uses KERN_EMERG and commit

  b0f4c4b3 ("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: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarThomas 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
parent 95580809

arch/x86/include/asm/stacktrace.h

+0 −2
Original line number Diff line number Diff line
@@ -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;

arch/x86/kernel/dumpstack.c

+48 −1
Original line number Diff line number Diff line
@@ -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");

}

arch/x86/kernel/dumpstack_32.c

+0 −42
Original line number Diff line number Diff line
@@ -127,45 +127,3 @@ int get_stack_info(unsigned long *stack, struct task_struct *task, 
	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");

}

arch/x86/kernel/dumpstack_64.c

+0 −42
Original line number Diff line number Diff line
@@ -149,45 +149,3 @@ int get_stack_info(unsigned long *stack, struct task_struct *task, 
	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");

}