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From: Peter Zijlstra <peterz@infradead.org>
To: torvalds@linux-foundation.org, tglx@linutronix.de, hpa@zytor.com,
	julien.thierry@arm.com, will.deacon@arm.com, luto@amacapital.net,
	mingo@kernel.org, catalin.marinas@arm.com, james.morse@arm.com,
	valentin.schneider@arm.com, brgerst@gmail.com,
	jpoimboe@redhat.com, luto@kernel.org, bp@alien8.de,
	dvlasenk@redhat.com
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
	dvyukov@google.com, rostedt@goodmis.org
Subject: [PATCH 04/20] x86/uaccess: Fix up the fixup
Date: Thu, 07 Mar 2019 12:45:15 +0100	[thread overview]
Message-ID: <20190307115159.438734452@infradead.org> (raw)
In-Reply-To: 20190307114511.870090179@infradead.org

arch/x86/lib/memcpy_64.o: warning: objtool: .fixup+0x7: return with UACCESS enabled

While the code isn't wrong; it is tedious (if at all possible) to
figure out what function a particular chunk of .fixup belongs to.

This then confuses the objtool uaccess validation. Instead of
returning directly from the .fixup, jump back into the right function.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/lib/memcpy_64.S |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -257,6 +257,7 @@ ENTRY(__memcpy_mcsafe)
 	/* Copy successful. Return zero */
 .L_done_memcpy_trap:
 	xorl %eax, %eax
+.L_done:
 	ret
 ENDPROC(__memcpy_mcsafe)
 EXPORT_SYMBOL_GPL(__memcpy_mcsafe)
@@ -273,7 +274,7 @@ EXPORT_SYMBOL_GPL(__memcpy_mcsafe)
 	addl	%edx, %ecx
 .E_trailing_bytes:
 	mov	%ecx, %eax
-	ret
+	jmp	.L_done
 
 	/*
 	 * For write fault handling, given the destination is unaligned,



  parent reply	other threads:[~2019-03-07 11:53 UTC|newest]

Thread overview: 100+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-07 11:45 [PATCH 00/20] objtool: UACCESS validation v3 Peter Zijlstra
2019-03-07 11:45 ` [PATCH 01/20] x86/ia32: Fix ia32_restore_sigcontext AC leak Peter Zijlstra
2019-03-07 11:45 ` [PATCH 02/20] i915,uaccess: Fix redundant CLAC Peter Zijlstra
2019-03-07 11:45 ` [PATCH 03/20] x86/uaccess: Move copy_user_handle_tail into asm Peter Zijlstra
2019-03-08 18:53   ` Josh Poimboeuf
2019-03-08 19:48     ` Peter Zijlstra
2019-03-08 19:53       ` Josh Poimboeuf
2019-03-10 13:22         ` Peter Zijlstra
2019-03-07 11:45 ` Peter Zijlstra [this message]
2019-03-07 11:45 ` [PATCH 05/20] x86/uaccess/xen: Suppress SMAP warnings Peter Zijlstra
2019-03-07 12:22   ` Juergen Gross
2019-03-07 12:32     ` Peter Zijlstra
2019-03-07 12:36       ` Juergen Gross
2019-03-08 19:00   ` Josh Poimboeuf
2019-03-08 19:03     ` Josh Poimboeuf
2019-03-10 13:19       ` Peter Zijlstra
2019-03-11 17:59         ` Josh Poimboeuf
2019-03-08 19:50     ` Peter Zijlstra
2019-03-07 11:45 ` [PATCH 06/20] x86/uaccess: Always inline user_access_begin() Peter Zijlstra
2019-03-07 11:45 ` [PATCH 07/20] x86/uaccess: Always inline force_valid_ss() Peter Zijlstra
2019-03-07 13:50   ` Peter Zijlstra
2019-03-07 18:05   ` Andy Lutomirski
2019-03-07 18:59     ` Peter Zijlstra
2019-03-07 19:06       ` Andy Lutomirski
2019-03-07 11:45 ` [PATCH 08/20] x86/uaccess: Introduce user_access_{save,restore}() Peter Zijlstra
2019-03-07 11:45 ` [PATCH 09/20] x86/uaccess,kasan: Fix KASAN vs SMAP Peter Zijlstra
2019-03-07 11:45 ` [PATCH 10/20] x86/uaccess,ubsan: Fix UBSAN " Peter Zijlstra
2019-03-07 11:45 ` [PATCH 11/20] x86/uaccess,ftrace: Fix ftrace_likely_update() " Peter Zijlstra
2019-03-07 11:45 ` [PATCH 12/20] objtool: Set insn->func for alternatives Peter Zijlstra
2019-03-08 19:16   ` Josh Poimboeuf
2019-03-08 19:51     ` Peter Zijlstra
2019-03-07 11:45 ` [PATCH 13/20] objtool: Hande function aliases Peter Zijlstra
2019-03-08 19:23   ` Josh Poimboeuf
2019-03-08 19:52     ` Peter Zijlstra
2019-03-08 20:00       ` Josh Poimboeuf
2019-03-07 11:45 ` [PATCH 14/20] objtool: Rewrite add_ignores() Peter Zijlstra
2019-03-08 19:29   ` Josh Poimboeuf
2019-03-07 11:45 ` [PATCH 15/20] objtool: Add --backtrace support Peter Zijlstra
2019-03-08 19:33   ` Josh Poimboeuf
2019-03-07 11:45 ` [PATCH 16/20] objtool: Rewrite alt->skip_orig Peter Zijlstra
2019-03-08 20:15   ` Josh Poimboeuf
2019-03-08 21:34     ` Peter Zijlstra
2019-03-08 22:27       ` Josh Poimboeuf
2019-03-07 11:45 ` [PATCH 17/20] objtool: Fix sibling call detection Peter Zijlstra
2019-03-08 20:22   ` Josh Poimboeuf
2019-03-07 11:45 ` [PATCH 18/20] objtool: Add UACCESS validation Peter Zijlstra
2019-03-07 16:33   ` Linus Torvalds
2019-03-07 17:10     ` hpa
2019-03-07 17:41     ` Peter Zijlstra
2019-03-07 17:54       ` Linus Torvalds
2019-03-07 18:48         ` Peter Zijlstra
2019-03-07 18:51           ` hpa
2019-03-07 19:03           ` Peter Zijlstra
2019-03-08 15:01             ` Josh Poimboeuf
2019-03-08 15:07               ` Peter Zijlstra
2019-03-07 20:23           ` Peter Zijlstra
2019-03-07 20:40             ` Peter Zijlstra
2019-03-08 15:07               ` Josh Poimboeuf
2019-03-08 15:23                 ` Peter Zijlstra
2019-03-07 20:15       ` Andrey Ryabinin
2019-03-07 20:33         ` Peter Zijlstra
2019-03-07 20:40           ` Andrey Ryabinin
2019-03-07 20:42           ` Peter Zijlstra
2019-03-08 21:02   ` Josh Poimboeuf
2019-03-08 21:31     ` Peter Zijlstra
2019-03-08 21:54       ` Josh Poimboeuf
2019-03-10 13:10     ` Peter Zijlstra
2019-03-11 18:01       ` Josh Poimboeuf
2019-03-07 11:45 ` [PATCH 19/20] objtool: uaccess PUSHF/POPF support Peter Zijlstra
2019-03-08 21:11   ` Josh Poimboeuf
2019-03-10 13:12     ` Peter Zijlstra
2019-03-07 11:45 ` [PATCH 20/20] objtool: Add Direction Flag validation Peter Zijlstra
2019-03-08 21:16   ` Josh Poimboeuf
2019-03-08 21:33     ` Peter Zijlstra
2019-03-08 21:56       ` Josh Poimboeuf
2019-03-10 13:13         ` Peter Zijlstra
2019-03-11 18:00           ` Josh Poimboeuf
2019-03-07 12:03 ` [PATCH 00/20] objtool: UACCESS validation v3 Peter Zijlstra
2019-03-07 12:55   ` Peter Zijlstra
2019-03-07 13:13     ` Peter Zijlstra
2019-03-07 16:47       ` Josh Poimboeuf
2019-03-07 16:50         ` Josh Poimboeuf
2019-03-07 17:00         ` Linus Torvalds
2019-03-07 17:17           ` Josh Poimboeuf
2019-03-07 17:38             ` Peter Zijlstra
2019-03-07 17:45               ` Linus Torvalds
2019-03-07 18:18                 ` Steven Rostedt
2019-03-10 13:16                   ` Peter Zijlstra
2019-04-19 10:08                     ` [PATCH] compiler.h, tracing: Remove CONFIG_PROFILE_ALL_BRANCHES Ingo Molnar
2019-04-19 13:04                       ` Steven Rostedt
2019-03-07 17:04         ` [PATCH 00/20] objtool: UACCESS validation v3 hpa
2019-03-07 17:18           ` Josh Poimboeuf
2019-03-07 17:29             ` hpa
2019-03-07 17:45               ` Josh Poimboeuf
2019-03-07 17:48                 ` Linus Torvalds
2019-03-07 17:43         ` Peter Zijlstra
2019-03-07 17:48           ` Josh Poimboeuf
2019-04-03  8:21             ` [tip:core/objtool] tracing: Improve "if" macro code generation tip-bot for Josh Poimboeuf
2019-03-07 16:31   ` [PATCH 00/20] objtool: UACCESS validation v3 Linus Torvalds
2019-03-07 17:14 ` hpa

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