The following commit has been merged into the x86/core branch of tip:
Commit-ID: 5fc77b916cb82fe476ae2344e0ec37445227a4f8
Gitweb: https://git.kernel.org/tip/5fc77b916cb82fe476ae2344e0ec37445227a4f8
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Wed, 10 Nov 2021 11:01:15 +01:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Sat, 11 Dec 2021 09:09:48 +01:00
x86/segment: Remove .fixup usage
Create and use EX_TYPE_ZERO_REG to clear the register and retry the
segment load on exception.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20211110101325.663529463@xxxxxxxxxxxxx
---
arch/x86/include/asm/extable_fixup_types.h | 1 +
arch/x86/include/asm/segment.h | 9 +--------
2 files changed, 2 insertions(+), 8 deletions(-)
diff --git a/arch/x86/include/asm/extable_fixup_types.h b/arch/x86/include/asm/extable_fixup_types.h
index 7469038..a43b8c1 100644
--- a/arch/x86/include/asm/extable_fixup_types.h
+++ b/arch/x86/include/asm/extable_fixup_types.h
@@ -45,5 +45,6 @@
#define EX_TYPE_IMM_REG 17 /* reg := (long)imm */
#define EX_TYPE_EFAULT_REG (EX_TYPE_IMM_REG | EX_DATA_IMM(-EFAULT))
+#define EX_TYPE_ZERO_REG (EX_TYPE_IMM_REG | EX_DATA_IMM(0))
#endif
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index 8dd8e8e..b228c9d 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -307,14 +307,7 @@ do { \
\
asm volatile(" \n" \
"1: movl %k0,%%" #seg " \n" \
- \
- ".section .fixup,\"ax\" \n" \
- "2: xorl %k0,%k0 \n" \
- " jmp 1b \n" \
- ".previous \n" \
- \
- _ASM_EXTABLE(1b, 2b) \
- \
+ _ASM_EXTABLE_TYPE_REG(1b, 1b, EX_TYPE_ZERO_REG, %k0)\
: "+r" (__val) : : "memory"); \
} while (0)
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