Messages in this thread | | | Date | Sat, 8 Feb 2014 21:22:30 -0800 | From | Andi Kleen <> | Subject | Re: [PATCH v13 8/9] Add 32 bit VDSO time support for 32 bit kernel |
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> +notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) > +{ > + long ret; > + > + asm( > + "push %%ebx \n" > + "mov %2,%%ebx \n" > + "call VDSO32_vsyscall \n" > + "pop %%ebx \n" > + : "=a" (ret) > + : "0" (__NR_clock_gettime), "d" (clock), "c" (ts) > + : "memory");
The push/mov/pop could be just replaced with "b"? Also I if this calls syscall.S:__kernel_vsyscall it clobbers more registers (ecx at least?) and you need to describe that to gcc with a +
Same in the other sys calls.
> @@ -310,6 +311,11 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) > unsigned long addr; > int ret = 0; > bool compat; > + struct vm_area_struct *vma; > + extern char __vvar_page; > +#ifdef CONFIG_HPET_TIMER > + extern unsigned long hpet_address; > +#endif
Put this into a header.
> +++ b/arch/x86/vdso/vdso32/vclock_gettime.c > @@ -0,0 +1,16 @@ > +#define BUILD_VDSO32 > + > +#ifdef CONFIG_X86_64 > + > +#define _ASM_X86_PAGE_H > + > +#define __pa(x) 0 > +#define __va(x) 0 > + > +#undef CONFIG_ILLEGAL_POINTER_VALUE > +#define CONFIG_ILLEGAL_POINTER_VALUE 0
This needs some comments.
Why are the __pa/__va defines safe?
The rest of the patchkit looks reasonable to me from a quick read. Much better than the first version.
-Andi
-- ak@linux.intel.com -- Speaking for myself only
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