diff options
Diffstat (limited to 'kernel/arch/x86/kernel/paravirt.c')
| -rw-r--r-- | kernel/arch/x86/kernel/paravirt.c | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/kernel/arch/x86/kernel/paravirt.c b/kernel/arch/x86/kernel/paravirt.c index c614dd492..c2130aef3 100644 --- a/kernel/arch/x86/kernel/paravirt.c +++ b/kernel/arch/x86/kernel/paravirt.c @@ -41,10 +41,18 @@ #include <asm/timer.h> #include <asm/special_insns.h> -/* nop stub */ -void _paravirt_nop(void) -{ -} +/* + * nop stub, which must not clobber anything *including the stack* to + * avoid confusing the entry prologues. + */ +extern void _paravirt_nop(void); +asm (".pushsection .entry.text, \"ax\"\n" + ".global _paravirt_nop\n" + "_paravirt_nop:\n\t" + "ret\n\t" + ".size _paravirt_nop, . - _paravirt_nop\n\t" + ".type _paravirt_nop, @function\n\t" + ".popsection"); /* identity function, which can be inlined */ u32 _paravirt_ident_32(u32 x) @@ -154,7 +162,9 @@ unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf, ret = paravirt_patch_ident_64(insnbuf, len); else if (type == PARAVIRT_PATCH(pv_cpu_ops.iret) || +#ifdef CONFIG_X86_32 type == PARAVIRT_PATCH(pv_cpu_ops.irq_enable_sysexit) || +#endif type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret32) || type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret64)) /* If operation requires a jmp, then jmp */ @@ -349,9 +359,7 @@ __visible struct pv_cpu_ops pv_cpu_ops = { .wbinvd = native_wbinvd, .read_msr = native_read_msr_safe, .write_msr = native_write_msr_safe, - .read_tsc = native_read_tsc, .read_pmc = native_read_pmc, - .read_tscp = native_read_tscp, .load_tr_desc = native_load_tr_desc, .set_ldt = native_set_ldt, .load_gdt = native_load_gdt, @@ -371,7 +379,7 @@ __visible struct pv_cpu_ops pv_cpu_ops = { .load_sp0 = native_load_sp0, -#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION) +#if defined(CONFIG_X86_32) .irq_enable_sysexit = native_irq_enable_sysexit, #endif #ifdef CONFIG_X86_64 |