renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2025-01-22 20:43:56 +08:00
Code

x86/paravirt: Switch iret pvops to ALTERNATIVE

Browse Source 
The iret paravirt op is rather special as it is using a jmp instead
of a call instruction. Switch it to ALTERNATIVE.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210311142319.4723-12-jgross@suse.com
This commit is contained in:
Juergen Gross 2021-03-11 15:23:16 +01:00 committed by Borislav Petkov
parent 0b8d366a94
commit ae755b5a45
5 changed files with 7 additions and 38 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
arch/x86/include/asm/paravirt.h
View File

@ -747,9 +747,9 @@ extern void default_banner(void);
#define PARA_INDIRECT(addr) *addr(%rip)
#define INTERRUPT_RETURN \
PARA_SITE(PARA_PATCH(PV_CPU_iret), \
ANNOTATE_RETPOLINE_SAFE; \
jmp PARA_INDIRECT(pv_ops+PV_CPU_iret);)
ANNOTATE_RETPOLINE_SAFE; \
ALTERNATIVE_TERNARY("jmp *paravirt_iret(%rip);", \
X86_FEATURE_XENPV, "jmp xen_iret;", "jmp native_iret;")
#ifdef CONFIG_DEBUG_ENTRY
#define SAVE_FLAGS(clobbers) \

5
arch/x86/include/asm/paravirt_types.h
View File

@ -151,10 +151,6 @@ struct pv_cpu_ops {
u64 (*read_pmc)(int counter);
/* Normal iret. Jump to this with the standard iret stack
frame set up. */
void (*iret)(void);
void (*start_context_switch)(struct task_struct *prev);
void (*end_context_switch)(struct task_struct *next);
#endif
@ -294,6 +290,7 @@ struct paravirt_patch_template {
extern struct pv_info pv_info;
extern struct paravirt_patch_template pv_ops;
extern void (*paravirt_iret)(void);
#define PARAVIRT_PATCH(x) \
(offsetof(struct paravirt_patch_template, x) / sizeof(void *))

5
arch/x86/kernel/asm-offsets.c
View File

@ -61,11 +61,6 @@ static void __used common(void)
OFFSET(IA32_RT_SIGFRAME_sigcontext, rt_sigframe_ia32, uc.uc_mcontext);
#endif
#ifdef CONFIG_PARAVIRT_XXL
BLANK();
OFFSET(PV_CPU_iret, paravirt_patch_template, cpu.iret);
#endif
#ifdef CONFIG_XEN
BLANK();
OFFSET(XEN_vcpu_info_mask, vcpu_info, evtchn_upcall_mask);

26
arch/x86/kernel/paravirt.c
View File

@ -86,25 +86,6 @@ u64 notrace _paravirt_ident_64(u64 x)
{
return x;
}
static unsigned paravirt_patch_jmp(void *insn_buff, const void *target,
unsigned long addr, unsigned len)
{
struct branch *b = insn_buff;
unsigned long delta = (unsigned long)target - (addr+5);
if (len < 5) {
#ifdef CONFIG_RETPOLINE
WARN_ONCE(1, "Failing to patch indirect JMP in %ps\n", (void *)addr);
#endif
return len; /* call too long for patch site */
}
b->opcode = 0xe9; /* jmp */
b->delta = delta;
return 5;
}
#endif
DEFINE_STATIC_KEY_TRUE(virt_spin_lock_key);
@ -136,9 +117,6 @@ unsigned paravirt_patch_default(u8 type, void *insn_buff,
else if (opfunc == _paravirt_ident_64)
ret = paravirt_patch_ident_64(insn_buff, len);
else if (type == PARAVIRT_PATCH(cpu.iret))
/* If operation requires a jmp, then jmp */
ret = paravirt_patch_jmp(insn_buff, opfunc, addr, len);
#endif
else
/* Otherwise call the function. */
@ -313,8 +291,6 @@ struct paravirt_patch_template pv_ops = {
.cpu.load_sp0 = native_load_sp0,
.cpu.iret = native_iret,
#ifdef CONFIG_X86_IOPL_IOPERM
.cpu.invalidate_io_bitmap = native_tss_invalidate_io_bitmap,
.cpu.update_io_bitmap = native_tss_update_io_bitmap,
@ -419,6 +395,8 @@ struct paravirt_patch_template pv_ops = {
NOKPROBE_SYMBOL(native_get_debugreg);
NOKPROBE_SYMBOL(native_set_debugreg);
NOKPROBE_SYMBOL(native_load_idt);
void (*paravirt_iret)(void) = native_iret;
#endif
EXPORT_SYMBOL(pv_ops);

3
arch/x86/xen/enlighten_pv.c
View File

@ -1070,8 +1070,6 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {
.read_pmc = xen_read_pmc,
.iret = xen_iret,
.load_tr_desc = paravirt_nop,
.set_ldt = xen_set_ldt,
.load_gdt = xen_load_gdt,
@ -1235,6 +1233,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
pv_info = xen_info;
pv_ops.init.patch = paravirt_patch_default;
pv_ops.cpu = xen_cpu_ops;
paravirt_iret = xen_iret;
xen_init_irq_ops();
/*