Re: [PATCH 2/5] x86/ELF: don't open-code read_sreg()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 28/09/2020 13:05, Jan Beulich wrote:
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
>
> --- a/xen/include/asm-x86/x86_64/elf.h
> +++ b/xen/include/asm-x86/x86_64/elf.h
> @@ -1,6 +1,8 @@
>  #ifndef __X86_64_ELF_H__
>  #define __X86_64_ELF_H__
>  
> +#include <asm/regs.h>
> +
>  typedef struct {
>      unsigned long r15;
>      unsigned long r14;
> @@ -53,16 +55,16 @@ static inline void elf_core_save_regs(EL
>      asm volatile("movq %%rdi,%0" : "=m"(core_regs->rdi));
>      /* orig_rax not filled in for now */
>      core_regs->rip = (unsigned long)elf_core_save_regs;
> -    asm volatile("movl %%cs, %%eax;" :"=a"(core_regs->cs));
> +    core_regs->cs = read_sreg(cs);
>      asm volatile("pushfq; popq %0" :"=m"(core_regs->rflags));
>      asm volatile("movq %%rsp,%0" : "=m"(core_regs->rsp));
>      asm volatile("movl %%ss, %%eax;" :"=a"(core_regs->ss));

Another one here.

With that fixed, Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

>      /* thread_fs not filled in for now */
>      /* thread_gs not filled in for now */
> -    asm volatile("movl %%ds, %%eax;" :"=a"(core_regs->ds));
> -    asm volatile("movl %%es, %%eax;" :"=a"(core_regs->es));
> -    asm volatile("movl %%fs, %%eax;" :"=a"(core_regs->fs));
> -    asm volatile("movl %%gs, %%eax;" :"=a"(core_regs->gs));
> +    core_regs->ds = read_sreg(ds);
> +    core_regs->es = read_sreg(es);
> +    core_regs->fs = read_sreg(fs);
> +    core_regs->gs = read_sreg(gs);
>  
>      asm volatile("mov %%cr0, %0" : "=r" (tmp) : );
>      xen_core_regs->cr0 = tmp;