[tip: x86/misc] x86/dumpstack: Don't mention RIP in "Code: "

From: tip-bot2 for Jiri Slaby
Date: Tue Sep 20 2022 - 10:24:51 EST


The following commit has been merged into the x86/misc branch of tip:

Commit-ID: 5258b80e60da6d8908ae2846b234ed8d9d9d4a19
Gitweb: https://git.kernel.org/tip/5258b80e60da6d8908ae2846b234ed8d9d9d4a19
Author: Jiri Slaby <jslaby@xxxxxxx>
AuthorDate: Tue, 06 Sep 2022 09:11:23 +02:00
Committer: Borislav Petkov <bp@xxxxxxx>
CommitterDate: Tue, 20 Sep 2022 16:11:54 +02:00

x86/dumpstack: Don't mention RIP in "Code: "

Commit

238c91115cd0 ("x86/dumpstack: Fix misleading instruction pointer error message")

changed the "Code:" line in bug reports when RIP is an invalid pointer.
In particular, the report currently says (for example):

BUG: kernel NULL pointer dereference, address: 0000000000000000
...
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.

That

Unable to access opcode bytes at RIP 0xffffffffffffffd6.

is quite confusing as RIP value is 0, not -42. That -42 comes from
"regs->ip - PROLOGUE_SIZE", because Code is dumped with some prologue
(and epilogue).

So do not mention "RIP" on this line in this context.

Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Link: https://lore.kernel.org/r/b772c39f-c5ae-8f17-fe6e-6a2bc4d1f83b@xxxxxxxxxx
---
arch/x86/kernel/dumpstack.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index afae4dd..b3dba35 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -128,7 +128,7 @@ void show_opcodes(struct pt_regs *regs, const char *loglvl)
/* No access to the user space stack of other tasks. Ignore. */
break;
default:
- printk("%sCode: Unable to access opcode bytes at RIP 0x%lx.\n",
+ printk("%sCode: Unable to access opcode bytes at 0x%lx.\n",
loglvl, prologue);
break;
}