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authorJuergen Gross <jgross@suse.com>2021-03-11 15:23:16 +0100
committerBorislav Petkov <bp@suse.de>2021-03-11 19:58:54 +0100
commitae755b5a45482b5de4d96d6f35823076af77445e (patch)
treeb617f4d18ead2e9c92e92f33b6b85086e1747b13 /arch/x86/kernel/paravirt.c
parent0b8d366a942fd48a83dfa728e9f8a8d8b20e735f (diff)
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x86/paravirt: Switch iret pvops to ALTERNATIVE
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
Diffstat (limited to 'arch/x86/kernel/paravirt.c')
-rw-r--r--arch/x86/kernel/paravirt.c26
1 files changed, 2 insertions, 24 deletions
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index a688edf35e31..9b0f568b0200 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -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);