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Subject[PATCH 4.19 209/276] x86/uaccess: Fix up the fixup
Date
[ Upstream commit b69656fa7ea2f75e47d7bd5b9430359fa46488af ]

New tooling got confused about this:

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>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/lib/memcpy_64.S | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index 3b24dc05251c7..9d05572370edc 100644
--- 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,
--
2.20.1


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