[PATCH] x86/kexec: Merge x86_32 and x86_64 code using macros from asm.h

From: Uros Bizjak
Date: Wed Mar 05 2025 - 11:31:46 EST


Merge common x86_32 and x86_64 code in crash_setup_regs()
using macros from asm/asm.h.

The compiled object files before and after the patch are unchanged.

Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
---
arch/x86/include/asm/asm.h | 2 ++
arch/x86/include/asm/kexec.h | 44 +++++++++++++++---------------------
2 files changed, 20 insertions(+), 26 deletions(-)

diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
index 975ae7a9397e..2bccc063d30b 100644
--- a/arch/x86/include/asm/asm.h
+++ b/arch/x86/include/asm/asm.h
@@ -41,6 +41,8 @@
#define _ASM_SUB __ASM_SIZE(sub)
#define _ASM_XADD __ASM_SIZE(xadd)
#define _ASM_MUL __ASM_SIZE(mul)
+#define _ASM_PUSHF __ASM_SIZE(pushf)
+#define _ASM_POP __ASM_SIZE(pop)

#define _ASM_AX __ASM_REG(ax)
#define _ASM_BX __ASM_REG(bx)
diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
index 8ad187462b68..56040ae6bda0 100644
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -18,6 +18,7 @@
#include <linux/string.h>
#include <linux/kernel.h>

+#include <asm/asm.h>
#include <asm/page.h>
#include <asm/ptrace.h>

@@ -71,29 +72,15 @@ static inline void crash_setup_regs(struct pt_regs *newregs,
if (oldregs) {
memcpy(newregs, oldregs, sizeof(*newregs));
} else {
-#ifdef CONFIG_X86_32
- asm volatile("movl %%ebx,%0" : "=m"(newregs->bx));
- asm volatile("movl %%ecx,%0" : "=m"(newregs->cx));
- asm volatile("movl %%edx,%0" : "=m"(newregs->dx));
- asm volatile("movl %%esi,%0" : "=m"(newregs->si));
- asm volatile("movl %%edi,%0" : "=m"(newregs->di));
- asm volatile("movl %%ebp,%0" : "=m"(newregs->bp));
- asm volatile("movl %%eax,%0" : "=m"(newregs->ax));
- asm volatile("movl %%esp,%0" : "=m"(newregs->sp));
- asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
- asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
- asm volatile("movl %%ds, %%eax;" :"=a"(newregs->ds));
- asm volatile("movl %%es, %%eax;" :"=a"(newregs->es));
- asm volatile("pushfl; popl %0" :"=m"(newregs->flags));
-#else
- asm volatile("movq %%rbx,%0" : "=m"(newregs->bx));
- asm volatile("movq %%rcx,%0" : "=m"(newregs->cx));
- asm volatile("movq %%rdx,%0" : "=m"(newregs->dx));
- asm volatile("movq %%rsi,%0" : "=m"(newregs->si));
- asm volatile("movq %%rdi,%0" : "=m"(newregs->di));
- asm volatile("movq %%rbp,%0" : "=m"(newregs->bp));
- asm volatile("movq %%rax,%0" : "=m"(newregs->ax));
- asm volatile("movq %%rsp,%0" : "=m"(newregs->sp));
+ asm volatile(_ASM_MOV " %%" _ASM_BX ",%0" : "=m"(newregs->bx));
+ asm volatile(_ASM_MOV " %%" _ASM_CX ",%0" : "=m"(newregs->cx));
+ asm volatile(_ASM_MOV " %%" _ASM_DX ",%0" : "=m"(newregs->dx));
+ asm volatile(_ASM_MOV " %%" _ASM_SI ",%0" : "=m"(newregs->si));
+ asm volatile(_ASM_MOV " %%" _ASM_DI ",%0" : "=m"(newregs->di));
+ asm volatile(_ASM_MOV " %%" _ASM_BP ",%0" : "=m"(newregs->bp));
+ asm volatile(_ASM_MOV " %%" _ASM_AX ",%0" : "=m"(newregs->ax));
+ asm volatile(_ASM_MOV " %%" _ASM_SP ",%0" : "=m"(newregs->sp));
+#ifdef CONFIG_X86_64
asm volatile("movq %%r8,%0" : "=m"(newregs->r8));
asm volatile("movq %%r9,%0" : "=m"(newregs->r9));
asm volatile("movq %%r10,%0" : "=m"(newregs->r10));
@@ -102,10 +89,15 @@ static inline void crash_setup_regs(struct pt_regs *newregs,
asm volatile("movq %%r13,%0" : "=m"(newregs->r13));
asm volatile("movq %%r14,%0" : "=m"(newregs->r14));
asm volatile("movq %%r15,%0" : "=m"(newregs->r15));
- asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
- asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
- asm volatile("pushfq; popq %0" :"=m"(newregs->flags));
#endif
+ asm volatile("movl %%ss,%k0" :"=a"(newregs->ss));
+ asm volatile("movl %%cs,%k0" :"=a"(newregs->cs));
+#ifdef CONFIG_X86_32
+ asm volatile("movl %%ds,%k0" :"=a"(newregs->ds));
+ asm volatile("movl %%es,%k0" :"=a"(newregs->es));
+#endif
+ asm volatile(_ASM_PUSHF "\n\t"
+ _ASM_POP " %0" : "=m"(newregs->flags));
newregs->ip = _THIS_IP_;
}
}
--
2.42.0