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-rw-r--r--arch/i386/kernel/alternative.c5
-rw-r--r--arch/i386/kernel/paravirt.c154
-rw-r--r--include/asm-i386/paravirt.h12
3 files changed, 144 insertions, 27 deletions
diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c
index dae3ded9041..c5d037c6095 100644
--- a/arch/i386/kernel/alternative.c
+++ b/arch/i386/kernel/alternative.c
@@ -336,11 +336,14 @@ void apply_paravirt(struct paravirt_patch_site *start,
used = paravirt_ops.patch(p->instrtype, p->clobbers, p->instr,
p->len);
+ BUG_ON(used > p->len);
+
/* Pad the rest with nops */
nop_out(p->instr + used, p->len - used);
}
- /* Sync to be conservative, in case we patched following instructions */
+ /* Sync to be conservative, in case we patched following
+ * instructions */
sync_core();
}
extern struct paravirt_patch_site __start_parainstructions[],
diff --git a/arch/i386/kernel/paravirt.c b/arch/i386/kernel/paravirt.c
index f2982832d3b..b0ed163e6f7 100644
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -54,40 +54,142 @@ char *memory_setup(void)
#define DEF_NATIVE(name, code) \
extern const char start_##name[], end_##name[]; \
asm("start_" #name ": " code "; end_" #name ":")
-DEF_NATIVE(cli, "cli");
-DEF_NATIVE(sti, "sti");
-DEF_NATIVE(popf, "push %eax; popf");
-DEF_NATIVE(pushf, "pushf; pop %eax");
+
+DEF_NATIVE(irq_disable, "cli");
+DEF_NATIVE(irq_enable, "sti");
+DEF_NATIVE(restore_fl, "push %eax; popf");
+DEF_NATIVE(save_fl, "pushf; pop %eax");
DEF_NATIVE(iret, "iret");
-DEF_NATIVE(sti_sysexit, "sti; sysexit");
+DEF_NATIVE(irq_enable_sysexit, "sti; sysexit");
+DEF_NATIVE(read_cr2, "mov %cr2, %eax");
+DEF_NATIVE(write_cr3, "mov %eax, %cr3");
+DEF_NATIVE(read_cr3, "mov %cr3, %eax");
+DEF_NATIVE(clts, "clts");
+DEF_NATIVE(read_tsc, "rdtsc");
-static const struct native_insns
-{
- const char *start, *end;
-} native_insns[] = {
- [PARAVIRT_PATCH(irq_disable)] = { start_cli, end_cli },
- [PARAVIRT_PATCH(irq_enable)] = { start_sti, end_sti },
- [PARAVIRT_PATCH(restore_fl)] = { start_popf, end_popf },
- [PARAVIRT_PATCH(save_fl)] = { start_pushf, end_pushf },
- [PARAVIRT_PATCH(iret)] = { start_iret, end_iret },
- [PARAVIRT_PATCH(irq_enable_sysexit)] = { start_sti_sysexit, end_sti_sysexit },
-};
+DEF_NATIVE(ud2a, "ud2a");
static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len)
{
- unsigned int insn_len;
+ const unsigned char *start, *end;
+ unsigned ret;
+
+ switch(type) {
+#define SITE(x) case PARAVIRT_PATCH(x): start = start_##x; end = end_##x; goto patch_site
+ SITE(irq_disable);
+ SITE(irq_enable);
+ SITE(restore_fl);
+ SITE(save_fl);
+ SITE(iret);
+ SITE(irq_enable_sysexit);
+ SITE(read_cr2);
+ SITE(read_cr3);
+ SITE(write_cr3);
+ SITE(clts);
+ SITE(read_tsc);
+#undef SITE
+
+ patch_site:
+ ret = paravirt_patch_insns(insns, len, start, end);
+ break;
+
+ case PARAVIRT_PATCH(make_pgd):
+ case PARAVIRT_PATCH(make_pte):
+ case PARAVIRT_PATCH(pgd_val):
+ case PARAVIRT_PATCH(pte_val):
+#ifdef CONFIG_X86_PAE
+ case PARAVIRT_PATCH(make_pmd):
+ case PARAVIRT_PATCH(pmd_val):
+#endif
+ /* These functions end up returning exactly what
+ they're passed, in the same registers. */
+ ret = paravirt_patch_nop();
+ break;
+
+ default:
+ ret = paravirt_patch_default(type, clobbers, insns, len);
+ break;
+ }
+
+ return ret;
+}
+
+unsigned paravirt_patch_nop(void)
+{
+ return 0;
+}
+
+unsigned paravirt_patch_ignore(unsigned len)
+{
+ return len;
+}
+
+unsigned paravirt_patch_call(void *target, u16 tgt_clobbers,
+ void *site, u16 site_clobbers,
+ unsigned len)
+{
+ unsigned char *call = site;
+ unsigned long delta = (unsigned long)target - (unsigned long)(call+5);
+
+ if (tgt_clobbers & ~site_clobbers)
+ return len; /* target would clobber too much for this site */
+ if (len < 5)
+ return len; /* call too long for patch site */
+
+ *call++ = 0xe8; /* call */
+ *(unsigned long *)call = delta;
+
+ return 5;
+}
+
+unsigned paravirt_patch_jmp(void *target, void *site, unsigned len)
+{
+ unsigned char *jmp = site;
+ unsigned long delta = (unsigned long)target - (unsigned long)(jmp+5);
- /* Don't touch it if we don't have a replacement */
- if (type >= ARRAY_SIZE(native_insns) || !native_insns[type].start)
- return len;
+ if (len < 5)
+ return len; /* call too long for patch site */
- insn_len = native_insns[type].end - native_insns[type].start;
+ *jmp++ = 0xe9; /* jmp */
+ *(unsigned long *)jmp = delta;
+
+ return 5;
+}
+
+unsigned paravirt_patch_default(u8 type, u16 clobbers, void *site, unsigned len)
+{
+ void *opfunc = *((void **)&paravirt_ops + type);
+ unsigned ret;
+
+ if (opfunc == NULL)
+ /* If there's no function, patch it with a ud2a (BUG) */
+ ret = paravirt_patch_insns(site, len, start_ud2a, end_ud2a);
+ else if (opfunc == paravirt_nop)
+ /* If the operation is a nop, then nop the callsite */
+ ret = paravirt_patch_nop();
+ else if (type == PARAVIRT_PATCH(iret) ||
+ type == PARAVIRT_PATCH(irq_enable_sysexit))
+ /* If operation requires a jmp, then jmp */
+ ret = paravirt_patch_jmp(opfunc, site, len);
+ else
+ /* Otherwise call the function; assume target could
+ clobber any caller-save reg */
+ ret = paravirt_patch_call(opfunc, CLBR_ANY,
+ site, clobbers, len);
+
+ return ret;
+}
+
+unsigned paravirt_patch_insns(void *site, unsigned len,
+ const char *start, const char *end)
+{
+ unsigned insn_len = end - start;
- /* Similarly if we can't fit replacement. */
- if (len < insn_len)
- return len;
+ if (insn_len > len || start == NULL)
+ insn_len = len;
+ else
+ memcpy(site, start, insn_len);
- memcpy(insns, native_insns[type].start, insn_len);
return insn_len;
}
@@ -110,7 +212,7 @@ static void native_flush_tlb_global(void)
__native_flush_tlb_global();
}
-static void native_flush_tlb_single(u32 addr)
+static void native_flush_tlb_single(unsigned long addr)
{
__native_flush_tlb_single(addr);
}
diff --git a/include/asm-i386/paravirt.h b/include/asm-i386/paravirt.h
index 8bfaf10d996..4b3d5085867 100644
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -248,6 +248,18 @@ extern struct paravirt_ops paravirt_ops;
#define paravirt_alt(insn_string) \
_paravirt_alt(insn_string, "%c[paravirt_typenum]", "%c[paravirt_clobber]")
+unsigned paravirt_patch_nop(void);
+unsigned paravirt_patch_ignore(unsigned len);
+unsigned paravirt_patch_call(void *target, u16 tgt_clobbers,
+ void *site, u16 site_clobbers,
+ unsigned len);
+unsigned paravirt_patch_jmp(void *target, void *site, unsigned len);
+unsigned paravirt_patch_default(u8 type, u16 clobbers, void *site, unsigned len);
+
+unsigned paravirt_patch_insns(void *site, unsigned len,
+ const char *start, const char *end);
+
+
/*
* This generates an indirect call based on the operation type number.
* The type number, computed in PARAVIRT_PATCH, is derived from the
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-14 12:33:41 +0000