linux-kernel - [PATCH] x86: remove the confusing entry in call trace

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <49296CEE.2070905@gmail.com>
Date:	Sun, 23 Nov 2008 22:47:10 +0800
From:	jia zhang <jia.zhang2008@...il.com>
To:	linux-kernel@...r.kernel.org
CC:	Ingo Molnar <mingo@...e.hu>, tglx@...utronix.de, hpa@...or.com
Subject: [PATCH] x86: remove the confusing entry in call trace


avoid the confusion in call trace because of the lack of padding at the tail of function.

Signed-off-by: jia zhang <jia.zhang2008@...il.com>
---
When do_exit get call, the return address behind call instruction is pushed into stack. If something get wrong in do_exit, for x86_64, the entry "kernel_execve +0x00/0xXX" rather than "child_rip +0xYY/0xZZ" is remained in call trace. It looks confused.

 b/arch/x86/kernel/entry_32.S |    1 +
 b/arch/x86/kernel/entry_64.S |    1 +
 2 files changed, 2 insertions(+)

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 28b597e..3290819 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -1051,6 +1051,7 @@ ENTRY(kernel_thread_helper)
 	push %eax
 	CFI_ADJUST_CFA_OFFSET 4
 	call do_exit
+	nop			# padding for call trace
 	CFI_ENDPROC
 ENDPROC(kernel_thread_helper)
 
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index b86f332..6f677a6 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1170,6 +1170,7 @@ child_rip:
 	# exit
 	mov %eax, %edi
 	call do_exit
+	nop			# padding for call trace
 	CFI_ENDPROC
 ENDPROC(child_rip)
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/