[tip: x86/core] x86/usercopy_32: Simplify __copy_user_intel_nocache()

From: tip-bot2 for Peter Zijlstra
Date: Mon Dec 13 2021 - 05:15:39 EST


The following commit has been merged into the x86/core branch of tip:

Commit-ID: 13e4bf1bddcb65dd028aaa492789e8d61efaafa1
Gitweb: https://git.kernel.org/tip/13e4bf1bddcb65dd028aaa492789e8d61efaafa1
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Wed, 10 Nov 2021 11:01:21 +01:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Sat, 11 Dec 2021 09:09:50 +01:00

x86/usercopy_32: Simplify __copy_user_intel_nocache()

Have an exception jump to a .fixup to only immediately jump out is
daft, jump to the right place in one go.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20211110101326.021517780@xxxxxxxxxxxxx
---
arch/x86/lib/usercopy_32.c | 40 ++++++++++++++++++-------------------
1 file changed, 20 insertions(+), 20 deletions(-)

diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c
index 962006b..1eb1506 100644
--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -256,28 +256,28 @@ static unsigned long __copy_user_intel_nocache(void *to,
"8:\n"
".section .fixup,\"ax\"\n"
"9: lea 0(%%eax,%0,4),%0\n"
- "16: jmp 8b\n"
+ " jmp 8b\n"
".previous\n"
- _ASM_EXTABLE_UA(0b, 16b)
- _ASM_EXTABLE_UA(1b, 16b)
- _ASM_EXTABLE_UA(2b, 16b)
- _ASM_EXTABLE_UA(21b, 16b)
- _ASM_EXTABLE_UA(3b, 16b)
- _ASM_EXTABLE_UA(31b, 16b)
- _ASM_EXTABLE_UA(4b, 16b)
- _ASM_EXTABLE_UA(41b, 16b)
- _ASM_EXTABLE_UA(10b, 16b)
- _ASM_EXTABLE_UA(51b, 16b)
- _ASM_EXTABLE_UA(11b, 16b)
- _ASM_EXTABLE_UA(61b, 16b)
- _ASM_EXTABLE_UA(12b, 16b)
- _ASM_EXTABLE_UA(71b, 16b)
- _ASM_EXTABLE_UA(13b, 16b)
- _ASM_EXTABLE_UA(81b, 16b)
- _ASM_EXTABLE_UA(14b, 16b)
- _ASM_EXTABLE_UA(91b, 16b)
+ _ASM_EXTABLE_UA(0b, 8b)
+ _ASM_EXTABLE_UA(1b, 8b)
+ _ASM_EXTABLE_UA(2b, 8b)
+ _ASM_EXTABLE_UA(21b, 8b)
+ _ASM_EXTABLE_UA(3b, 8b)
+ _ASM_EXTABLE_UA(31b, 8b)
+ _ASM_EXTABLE_UA(4b, 8b)
+ _ASM_EXTABLE_UA(41b, 8b)
+ _ASM_EXTABLE_UA(10b, 8b)
+ _ASM_EXTABLE_UA(51b, 8b)
+ _ASM_EXTABLE_UA(11b, 8b)
+ _ASM_EXTABLE_UA(61b, 8b)
+ _ASM_EXTABLE_UA(12b, 8b)
+ _ASM_EXTABLE_UA(71b, 8b)
+ _ASM_EXTABLE_UA(13b, 8b)
+ _ASM_EXTABLE_UA(81b, 8b)
+ _ASM_EXTABLE_UA(14b, 8b)
+ _ASM_EXTABLE_UA(91b, 8b)
_ASM_EXTABLE_UA(6b, 9b)
- _ASM_EXTABLE_UA(7b, 16b)
+ _ASM_EXTABLE_UA(7b, 8b)
: "=&c"(size), "=&D" (d0), "=&S" (d1)
: "1"(to), "2"(from), "0"(size)
: "eax", "edx", "memory");