From mboxrd@z Thu Jan 1 00:00:00 1970 Reply-To: kernel-hardening@lists.openwall.com From: Andy Lutomirski Date: Wed, 15 Jun 2016 17:28:31 -0700 Message-Id: In-Reply-To: References: In-Reply-To: References: Subject: [kernel-hardening] [PATCH 09/13] x86/dumpstack: When dumping stack bytes due to OOPS, start with regs->sp To: "linux-kernel@vger.kernel.org" , x86@kernel.org, Borislav Petkov Cc: Nadav Amit , Kees Cook , Brian Gerst , "kernel-hardening@lists.openwall.com" , Linus Torvalds , Josh Poimboeuf , Andy Lutomirski List-ID: The comment suggests that show_stack(NULL, NULL) should backtrace the current context, but the code doesn't match the comment. If regs are given, start the "Stack:" hexdump at regs->sp. Signed-off-by: Andy Lutomirski --- arch/x86/kernel/dumpstack_32.c | 4 +++- arch/x86/kernel/dumpstack_64.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c index 464ffd69b92e..91069ebe3c87 100644 --- a/arch/x86/kernel/dumpstack_32.c +++ b/arch/x86/kernel/dumpstack_32.c @@ -98,7 +98,9 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, int i; if (sp == NULL) { - if (task) + if (regs) + sp = (unsigned long *)regs->sp; + else if (task) sp = (unsigned long *)task->thread.sp; else sp = (unsigned long *)&sp; diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index 5f1c6266eb30..603356a5597a 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -266,7 +266,9 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, * back trace for this cpu: */ if (sp == NULL) { - if (task) + if (regs) + sp = (unsigned long *)regs->sp; + else if (task) sp = (unsigned long *)task->thread.sp; else sp = (unsigned long *)&sp; -- 2.7.4