Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7cccf072 authored by Borislav Petkov's avatar Borislav Petkov Committed by Thomas Gleixner
Browse files

x86/dumpstack: Add a show_ip() function 



... which shows the Instruction Pointer along with the insn bytes around
it. Use it whenever rIP is printed. Drop the rIP < PAGE_OFFSET check since
probe_kernel_read() can handle any address properly.

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/20180417161124.5294-8-bp@alien8.de
parent ba54d856

arch/x86/include/asm/stacktrace.h

+1 −0
Original line number Diff line number Diff line
@@ -112,4 +112,5 @@ static inline unsigned long caller_frame_pointer(void) 
}



void show_opcodes(u8 *rip, const char *loglvl);

void show_ip(struct pt_regs *regs, const char *loglvl);

#endif /* _ASM_X86_STACKTRACE_H */

arch/x86/kernel/dumpstack.c

+13 −10
Original line number Diff line number Diff line
@@ -94,9 +94,19 @@ void show_opcodes(u8 *rip, const char *loglvl) 
	pr_cont("\n");

}



void show_ip(struct pt_regs *regs, const char *loglvl)

{

#ifdef CONFIG_X86_32

	printk("%sEIP: %pS\n", loglvl, (void *)regs->ip);

#else

	printk("%sRIP: %04x:%pS\n", loglvl, (int)regs->cs, (void *)regs->ip);

#endif

	show_opcodes((u8 *)regs->ip, loglvl);

}



void show_iret_regs(struct pt_regs *regs)

{

	printk(KERN_DEFAULT "RIP: %04x:%pS\n", (int)regs->cs, (void *)regs->ip);

	show_ip(regs, KERN_DEFAULT);

	printk(KERN_DEFAULT "RSP: %04x:%016lx EFLAGS: %08lx", (int)regs->ss,

		regs->sp, regs->flags);

}
@@ -392,15 +402,8 @@ void show_regs(struct pt_regs *regs) 
	__show_regs(regs, all);



	/*

	 * When in-kernel, we also print out the stack and code at the

	 * time of the fault..

	 * When in-kernel, we also print out the stack at the time of the fault..

	 */

	if (!user_mode(regs)) {

	if (!user_mode(regs))

		show_trace_log_lvl(current, regs, NULL, KERN_DEFAULT);



		if (regs->ip < PAGE_OFFSET)

			printk(KERN_DEFAULT "Code: Bad RIP value.\n");

		else

			show_opcodes((u8 *)regs->ip, KERN_DEFAULT);

	}

}

arch/x86/kernel/process_32.c

+3 −5
Original line number Diff line number Diff line
@@ -76,16 +76,14 @@ void __show_regs(struct pt_regs *regs, int all) 
		savesegment(gs, gs);

	}



	printk(KERN_DEFAULT "EIP: %pS\n", (void *)regs->ip);

	printk(KERN_DEFAULT "EFLAGS: %08lx CPU: %d\n", regs->flags,

		raw_smp_processor_id());

	show_ip(regs, KERN_DEFAULT);



	printk(KERN_DEFAULT "EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",

		regs->ax, regs->bx, regs->cx, regs->dx);

	printk(KERN_DEFAULT "ESI: %08lx EDI: %08lx EBP: %08lx ESP: %08lx\n",

		regs->si, regs->di, regs->bp, sp);

	printk(KERN_DEFAULT " DS: %04x ES: %04x FS: %04x GS: %04x SS: %04x\n",

	       (u16)regs->ds, (u16)regs->es, (u16)regs->fs, gs, ss);

	printk(KERN_DEFAULT "DS: %04x ES: %04x FS: %04x GS: %04x SS: %04x EFLAGS: %08lx\n",

	       (u16)regs->ds, (u16)regs->es, (u16)regs->fs, gs, ss, regs->flags);



	if (!all)

		return;