diff mbox series

[5/5] x86/ELF: eliminate pointless local variable from elf_core_save_regs()

Message ID 47b0c4cf-df3b-ee07-f639-14ab6680f90f@suse.com (mailing list archive)
State New, archived
Headers show
Series x86: introduce read_sregs() and elf_core_save_regs() adjustments | expand

Commit Message

Jan Beulich Sept. 28, 2020, 12:07 p.m. UTC 
We can just as well specify the CRn structure fields directly in the
asm()s, just like done for all other ones.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

Comments

Andrew Cooper Sept. 28, 2020, 1:06 p.m. UTC | #1 
On 28/09/2020 13:07, Jan Beulich wrote:
> We can just as well specify the CRn structure fields directly in the
> asm()s, just like done for all other ones.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
diff mbox series

Patch

--- a/xen/include/asm-x86/x86_64/elf.h
+++ b/xen/include/asm-x86/x86_64/elf.h
@@ -37,8 +37,6 @@  typedef struct {
 static inline void elf_core_save_regs(ELF_Gregset *core_regs, 
                                       crash_xen_core_t *xen_core_regs)
 {
-    unsigned long tmp;
-
     asm volatile("movq %%r15,%0" : "=m"(core_regs->r15));
     asm volatile("movq %%r14,%0" : "=m"(core_regs->r14));
     asm volatile("movq %%r13,%0" : "=m"(core_regs->r13));
@@ -67,17 +65,10 @@  static inline void elf_core_save_regs(EL
     core_regs->fs = read_sreg(fs);
     core_regs->gs = read_sreg(gs);
 
-    asm volatile("mov %%cr0, %0" : "=r" (tmp) : );
-    xen_core_regs->cr0 = tmp;
-
-    asm volatile("mov %%cr2, %0" : "=r" (tmp) : );
-    xen_core_regs->cr2 = tmp;
-
-    asm volatile("mov %%cr3, %0" : "=r" (tmp) : );
-    xen_core_regs->cr3 = tmp;
-
-    asm volatile("mov %%cr4, %0" : "=r" (tmp) : );
-    xen_core_regs->cr4 = tmp;
+    asm volatile("mov %%cr0, %0" : "=r" (xen_core_regs->cr0));
+    asm volatile("mov %%cr2, %0" : "=r" (xen_core_regs->cr2));
+    asm volatile("mov %%cr3, %0" : "=r" (xen_core_regs->cr3));
+    asm volatile("mov %%cr4, %0" : "=r" (xen_core_regs->cr4));
 }
 
 #endif /* __X86_64_ELF_H__ */