Commit fc242af8 authored Apr 03, 2019 by Peter Zijlstra Committed by Greg Kroah-Hartman May 31, 2019

x86/uaccess: Fix up the fixup



[ 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>

parent 5007453c

arch/x86/lib/memcpy_64.S

+2 −1

Original line number	Diff line number	Diff line
		@@ -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,