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From: Josh Poimboeuf <jpoimboe@redhat.com>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org,
	Fengguang Wu <fengguang.wu@intel.com>,
	Byungchul Park <byungchul.park@lge.com>,
	Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>, LKP <lkp@01.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Subject: [PATCH 4/4] x86/unwind: Disable unwinder warnings on 32-bit
Date: Mon,  9 Oct 2017 20:20:05 -0500	[thread overview]
Message-ID: <a69658760800bf281e6353248c23e0fa0acf5230.1507597785.git.jpoimboe@redhat.com> (raw)
In-Reply-To: <cover.1507597785.git.jpoimboe@redhat.com>

x86-32 doesn't have stack validation, so in most cases it doesn't make
sense to warn about bad frame pointers.

Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
 arch/x86/kernel/unwind_frame.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c
index 81aca077fbb6..3dc26f95d46e 100644
--- a/arch/x86/kernel/unwind_frame.c
+++ b/arch/x86/kernel/unwind_frame.c
@@ -355,6 +355,13 @@ bool unwind_next_frame(struct unwind_state *state)
 	    state->regs->sp < (unsigned long)task_pt_regs(state->task))
 		goto the_end;
 
+	/*
+	 * There are some known frame pointer issues on 32-bit.  Disable
+	 * unwinder warnings on 32-bit until it gets objtool support.
+	 */
+	if (IS_ENABLED(CONFIG_X86_32))
+		goto the_end;
+
 	if (state->regs) {
 		printk_deferred_once(KERN_WARNING
 			"WARNING: kernel stack regs at %p in %s:%d has bad 'bp' value %p\n",
-- 
2.13.6

WARNING: multiple messages have this Message-ID (diff)
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: lkp@lists.01.org
Subject: [PATCH 4/4] x86/unwind: Disable unwinder warnings on 32-bit
Date: Mon, 09 Oct 2017 20:20:05 -0500	[thread overview]
Message-ID: <a69658760800bf281e6353248c23e0fa0acf5230.1507597785.git.jpoimboe@redhat.com> (raw)
In-Reply-To: <cover.1507597785.git.jpoimboe@redhat.com>

[-- Attachment #1: Type: text/plain, Size: 1024 bytes --]

x86-32 doesn't have stack validation, so in most cases it doesn't make
sense to warn about bad frame pointers.

Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
 arch/x86/kernel/unwind_frame.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c
index 81aca077fbb6..3dc26f95d46e 100644
--- a/arch/x86/kernel/unwind_frame.c
+++ b/arch/x86/kernel/unwind_frame.c
@@ -355,6 +355,13 @@ bool unwind_next_frame(struct unwind_state *state)
 	    state->regs->sp < (unsigned long)task_pt_regs(state->task))
 		goto the_end;
 
+	/*
+	 * There are some known frame pointer issues on 32-bit.  Disable
+	 * unwinder warnings on 32-bit until it gets objtool support.
+	 */
+	if (IS_ENABLED(CONFIG_X86_32))
+		goto the_end;
+
 	if (state->regs) {
 		printk_deferred_once(KERN_WARNING
 			"WARNING: kernel stack regs at %p in %s:%d has bad 'bp' value %p\n",
-- 
2.13.6


  parent reply	other threads:[~2017-10-10  1:20 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-10  1:20 [PATCH 0/4] x86/unwind: 32-bit unwinder fixes Josh Poimboeuf
2017-10-10  1:20 ` Josh Poimboeuf
2017-10-10  1:20 ` [PATCH 1/4] x86/unwind: Fix dereference of untrusted pointer Josh Poimboeuf
2017-10-10  1:20   ` Josh Poimboeuf
2017-10-10 14:55   ` [tip:x86/urgent] " tip-bot for Josh Poimboeuf
2017-10-10  1:20 ` [PATCH 2/4] x86/unwind: Use MSB for frame pointer encoding on 32-bit Josh Poimboeuf
2017-10-10  1:20   ` Josh Poimboeuf
2017-10-10 14:55   ` [tip:x86/urgent] " tip-bot for Josh Poimboeuf
2017-10-10  1:20 ` [PATCH 3/4] x86/unwind: Align stack pointer in unwinder dump Josh Poimboeuf
2017-10-10  1:20   ` Josh Poimboeuf
2017-10-10 14:55   ` [tip:x86/urgent] " tip-bot for Josh Poimboeuf
2017-10-10  1:20 ` Josh Poimboeuf [this message]
2017-10-10  1:20   ` [PATCH 4/4] x86/unwind: Disable unwinder warnings on 32-bit Josh Poimboeuf
2017-10-10 14:56   ` [tip:x86/urgent] " tip-bot for Josh Poimboeuf

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