@@ -89,6 +89,8 @@ struct alt_instr {
u8 replacementlen; /* length of new instruction */
} __packed;
+extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
+
/*
* Debug flag that can be tested to see whether alternative
* instructions were patched in already:
@@ -104,11 +106,10 @@ extern void apply_fineibt(s32 *start_retpoline, s32 *end_retpoine,
s32 *start_cfi, s32 *end_cfi);
struct module;
-struct paravirt_patch_site;
struct callthunk_sites {
s32 *call_start, *call_end;
- struct paravirt_patch_site *pv_start, *pv_end;
+ struct alt_instr *alt_start, *alt_end;
};
#ifdef CONFIG_CALL_THUNKS
@@ -730,35 +730,20 @@ extern void default_banner(void);
#else /* __ASSEMBLY__ */
-#define _PVSITE(ptype, ops, word, algn) \
-771:; \
- ops; \
-772:; \
- .pushsection .parainstructions,"a"; \
- .align algn; \
- word 771b; \
- .byte ptype; \
- .byte 772b-771b; \
- _ASM_ALIGN; \
- .popsection
-
-
#ifdef CONFIG_X86_64
#ifdef CONFIG_PARAVIRT_XXL
+#ifdef CONFIG_DEBUG_ENTRY
-#define PARA_PATCH(off) ((off) / 8)
-#define PARA_SITE(ptype, ops) _PVSITE(ptype, ops, .quad, 8)
#define PARA_INDIRECT(addr) *addr(%rip)
-#ifdef CONFIG_DEBUG_ENTRY
.macro PARA_IRQ_save_fl
- PARA_SITE(PARA_PATCH(PV_IRQ_save_fl),
- ANNOTATE_RETPOLINE_SAFE;
- call PARA_INDIRECT(pv_ops+PV_IRQ_save_fl);)
+ ANNOTATE_RETPOLINE_SAFE;
+ call PARA_INDIRECT(pv_ops+PV_IRQ_save_fl);
.endm
-#define SAVE_FLAGS ALTERNATIVE "PARA_IRQ_save_fl;", "pushf; pop %rax;", \
- ALT_NOT(X86_FEATURE_XENPV)
+#define SAVE_FLAGS ALTERNATIVE_2 "PARA_IRQ_save_fl;", ALT_CALL_INSTR, \
+ ALT_CALL_ALWAYS, "pushf; pop %rax;", \
+ ALT_NOT(X86_FEATURE_XENPV)
#endif
#endif /* CONFIG_PARAVIRT_XXL */
#endif /* CONFIG_X86_64 */
@@ -3,13 +3,6 @@
#define _ASM_X86_PARAVIRT_TYPES_H
#ifndef __ASSEMBLY__
-/* These all sit in the .parainstructions section to tell us what to patch. */
-struct paravirt_patch_site {
- u8 *instr; /* original instructions */
- u8 type; /* type of this instruction */
- u8 len; /* length of original instruction */
-};
-
/* Lazy mode for batching updates / context switch */
enum paravirt_lazy_mode {
PARAVIRT_LAZY_NONE,
@@ -257,43 +250,11 @@ struct paravirt_patch_template {
extern struct pv_info pv_info;
extern struct paravirt_patch_template pv_ops;
-#define PARAVIRT_PATCH(x) \
- (offsetof(struct paravirt_patch_template, x) / sizeof(void *))
-
-#define paravirt_type(op) \
- [paravirt_typenum] "i" (PARAVIRT_PATCH(op)), \
- [paravirt_opptr] "m" (pv_ops.op)
-/*
- * Generate some code, and mark it as patchable by the
- * apply_paravirt() alternate instruction patcher.
- */
-#define _paravirt_alt(insn_string, type) \
- "771:\n\t" insn_string "\n" "772:\n" \
- ".pushsection .parainstructions,\"a\"\n" \
- _ASM_ALIGN "\n" \
- _ASM_PTR " 771b\n" \
- " .byte " type "\n" \
- " .byte 772b-771b\n" \
- _ASM_ALIGN "\n" \
- ".popsection\n"
-
-/* Generate patchable code, with the default asm parameters. */
-#define paravirt_alt(insn_string) \
- _paravirt_alt(insn_string, "%c[paravirt_typenum]")
-
-/* Simple instruction patching code. */
-#define NATIVE_LABEL(a,x,b) "\n\t.globl " a #x "_" #b "\n" a #x "_" #b ":\n\t"
-
-unsigned int paravirt_patch(u8 type, void *insn_buff, unsigned long addr, unsigned int len);
+#define paravirt_ptr(op) [paravirt_opptr] "m" (pv_ops.op)
int paravirt_disable_iospace(void);
-/*
- * This generates an indirect call based on the operation type number.
- * The type number, computed in PARAVIRT_PATCH, is derived from the
- * offset into the paravirt_patch_template structure, and can therefore be
- * freely converted back into a structure offset.
- */
+/* This generates an indirect call based on the operation type number. */
#define PARAVIRT_CALL \
ANNOTATE_RETPOLINE_SAFE \
"call *%[paravirt_opptr];"
@@ -326,12 +287,6 @@ int paravirt_disable_iospace(void);
* However, x86_64 also has to clobber all caller saved registers, which
* unfortunately, are quite a bit (r8 - r11)
*
- * The call instruction itself is marked by placing its start address
- * and size into the .parainstructions section, so that
- * apply_paravirt() in arch/i386/kernel/alternative.c can do the
- * appropriate patching under the control of the backend pv_init_ops
- * implementation.
- *
* Unfortunately there's no way to get gcc to generate the args setup
* for the call, and then allow the call itself to be generated by an
* inline asm. Because of this, we must do the complete arg setup and
@@ -435,9 +390,10 @@ int paravirt_disable_iospace(void);
({ \
PVOP_CALL_ARGS; \
PVOP_TEST_NULL(op); \
- asm volatile(paravirt_alt(PARAVIRT_CALL) \
+ asm volatile(ALTERNATIVE(PARAVIRT_CALL, ALT_CALL_INSTR, \
+ ALT_CALL_ALWAYS) \
: call_clbr, ASM_CALL_CONSTRAINT \
- : paravirt_type(op), \
+ : paravirt_ptr(op), \
##__VA_ARGS__ \
: "memory", "cc" extra_clbr); \
ret; \
@@ -448,10 +404,11 @@ int paravirt_disable_iospace(void);
({ \
PVOP_CALL_ARGS; \
PVOP_TEST_NULL(op); \
- asm volatile(ALTERNATIVE(paravirt_alt(PARAVIRT_CALL), \
- alt, cond) \
+ asm volatile(ALTERNATIVE_2(PARAVIRT_CALL, \
+ ALT_CALL_INSTR, ALT_CALL_ALWAYS, \
+ alt, cond) \
: call_clbr, ASM_CALL_CONSTRAINT \
- : paravirt_type(op), \
+ : paravirt_ptr(op), \
##__VA_ARGS__ \
: "memory", "cc" extra_clbr); \
ret; \
@@ -568,9 +525,6 @@ unsigned long pv_native_read_cr2(void);
#define paravirt_nop ((void *)x86_nop)
-extern struct paravirt_patch_site __parainstructions[],
- __parainstructions_end[];
-
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_PARAVIRT */
#endif /* _ASM_X86_PARAVIRT_TYPES_H */
@@ -6,18 +6,6 @@
#include <linux/stddef.h>
#include <asm/ptrace.h>
-struct paravirt_patch_site;
-#ifdef CONFIG_PARAVIRT
-void apply_paravirt(struct paravirt_patch_site *start,
- struct paravirt_patch_site *end);
-#else
-static inline void apply_paravirt(struct paravirt_patch_site *start,
- struct paravirt_patch_site *end)
-{}
-#define __parainstructions NULL
-#define __parainstructions_end NULL
-#endif
-
/*
* Currently, the max observed size in the kernel code is
* JUMP_LABEL_NOP_SIZE/RELATIVEJUMP_SIZE, which are 5.
@@ -118,7 +118,6 @@ extern s32 __retpoline_sites[], __retpoline_sites_end[];
extern s32 __return_sites[], __return_sites_end[];
extern s32 __cfi_sites[], __cfi_sites_end[];
extern s32 __ibt_endbr_seal[], __ibt_endbr_seal_end[];
-extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
extern s32 __smp_locks[], __smp_locks_end[];
void text_poke_early(void *addr, const void *opcode, size_t len);
@@ -1265,32 +1264,6 @@ int alternatives_text_reserved(void *start, void *end)
}
#endif /* CONFIG_SMP */
-#ifdef CONFIG_PARAVIRT
-void __init_or_module apply_paravirt(struct paravirt_patch_site *start,
- struct paravirt_patch_site *end)
-{
- struct paravirt_patch_site *p;
- char insn_buff[MAX_PATCH_LEN];
-
- for (p = start; p < end; p++) {
- unsigned int used;
-
- BUG_ON(p->len > MAX_PATCH_LEN);
- /* prep the buffer with the original instructions */
- memcpy(insn_buff, p->instr, p->len);
- used = paravirt_patch(p->type, insn_buff, (unsigned long)p->instr, p->len);
-
- BUG_ON(used > p->len);
-
- /* Pad the rest with nops */
- add_nops(insn_buff + used, p->len - used);
- text_poke_early(p->instr, insn_buff, p->len);
- }
-}
-extern struct paravirt_patch_site __start_parainstructions[],
- __stop_parainstructions[];
-#endif /* CONFIG_PARAVIRT */
-
/*
* Self-test for the INT3 based CALL emulation code.
*
@@ -1396,28 +1369,11 @@ void __init alternative_instructions(void)
*/
/*
- * Paravirt patching and alternative patching can be combined to
- * replace a function call with a short direct code sequence (e.g.
- * by setting a constant return value instead of doing that in an
- * external function).
- * In order to make this work the following sequence is required:
- * 1. set (artificial) features depending on used paravirt
- * functions which can later influence alternative patching
- * 2. apply paravirt patching (generally replacing an indirect
- * function call with a direct one)
- * 3. apply alternative patching (e.g. replacing a direct function
- * call with a custom code sequence)
- * Doing paravirt patching after alternative patching would clobber
- * the optimization of the custom code with a function call again.
+ * Make sure to set (artificial) features depending on used paravirt
+ * functions which can later influence alternative patching.
*/
paravirt_set_cap();
- /*
- * First patch paravirt functions, such that we overwrite the indirect
- * call with the direct call.
- */
- apply_paravirt(__parainstructions, __parainstructions_end);
-
__apply_fineibt(__retpoline_sites, __retpoline_sites_end,
__cfi_sites, __cfi_sites_end, true);
@@ -1428,10 +1384,6 @@ void __init alternative_instructions(void)
apply_retpolines(__retpoline_sites, __retpoline_sites_end);
apply_returns(__return_sites, __return_sites_end);
- /*
- * Then patch alternatives, such that those paravirt calls that are in
- * alternatives can be overwritten by their immediate fragments.
- */
apply_alternatives(__alt_instructions, __alt_instructions_end);
/*
@@ -238,14 +238,13 @@ patch_call_sites(s32 *start, s32 *end, const struct core_text *ct)
}
static __init_or_module void
-patch_paravirt_call_sites(struct paravirt_patch_site *start,
- struct paravirt_patch_site *end,
- const struct core_text *ct)
+patch_alt_call_sites(struct alt_instr *start, struct alt_instr *end,
+ const struct core_text *ct)
{
- struct paravirt_patch_site *p;
+ struct alt_instr *a;
- for (p = start; p < end; p++)
- patch_call(p->instr, ct);
+ for (a = start; a < end; a++)
+ patch_call((u8 *)&a->instr_offset + a->instr_offset, ct);
}
static __init_or_module void
@@ -253,7 +252,7 @@ callthunks_setup(struct callthunk_sites *cs, const struct core_text *ct)
{
prdbg("Patching call sites %s\n", ct->name);
patch_call_sites(cs->call_start, cs->call_end, ct);
- patch_paravirt_call_sites(cs->pv_start, cs->pv_end, ct);
+ patch_alt_call_sites(cs->alt_start, cs->alt_end, ct);
prdbg("Patching call sites done%s\n", ct->name);
}
@@ -262,8 +261,8 @@ void __init callthunks_patch_builtin_calls(void)
struct callthunk_sites cs = {
.call_start = __call_sites,
.call_end = __call_sites_end,
- .pv_start = __parainstructions,
- .pv_end = __parainstructions_end
+ .alt_start = __alt_instructions,
+ .alt_end = __alt_instructions_end
};
if (!cpu_feature_enabled(X86_FEATURE_CALL_DEPTH))
@@ -276,7 +276,7 @@ int module_finalize(const Elf_Ehdr *hdr,
struct module *me)
{
const Elf_Shdr *s, *alt = NULL, *locks = NULL,
- *para = NULL, *orc = NULL, *orc_ip = NULL,
+ *orc = NULL, *orc_ip = NULL,
*retpolines = NULL, *returns = NULL, *ibt_endbr = NULL,
*calls = NULL, *cfi = NULL;
char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
@@ -286,8 +286,6 @@ int module_finalize(const Elf_Ehdr *hdr,
alt = s;
if (!strcmp(".smp_locks", secstrings + s->sh_name))
locks = s;
- if (!strcmp(".parainstructions", secstrings + s->sh_name))
- para = s;
if (!strcmp(".orc_unwind", secstrings + s->sh_name))
orc = s;
if (!strcmp(".orc_unwind_ip", secstrings + s->sh_name))
@@ -304,14 +302,6 @@ int module_finalize(const Elf_Ehdr *hdr,
ibt_endbr = s;
}
- /*
- * See alternative_instructions() for the ordering rules between the
- * various patching types.
- */
- if (para) {
- void *pseg = (void *)para->sh_addr;
- apply_paravirt(pseg, pseg + para->sh_size);
- }
if (retpolines || cfi) {
void *rseg = NULL, *cseg = NULL;
unsigned int rsize = 0, csize = 0;
@@ -341,7 +331,7 @@ int module_finalize(const Elf_Ehdr *hdr,
void *aseg = (void *)alt->sh_addr;
apply_alternatives(aseg, aseg + alt->sh_size);
}
- if (calls || para) {
+ if (calls || alt) {
struct callthunk_sites cs = {};
if (calls) {
@@ -349,9 +339,9 @@ int module_finalize(const Elf_Ehdr *hdr,
cs.call_end = (void *)calls->sh_addr + calls->sh_size;
}
- if (para) {
- cs.pv_start = (void *)para->sh_addr;
- cs.pv_end = (void *)para->sh_addr + para->sh_size;
+ if (alt) {
+ cs.alt_start = (void *)alt->sh_addr;
+ cs.alt_end = (void *)alt->sh_addr + alt->sh_size;
}
callthunks_patch_module_calls(&cs, me);
@@ -43,14 +43,6 @@ void __init default_banner(void)
pv_info.name);
}
-static unsigned paravirt_patch_call(void *insn_buff, const void *target,
- unsigned long addr, unsigned len)
-{
- __text_gen_insn(insn_buff, CALL_INSN_OPCODE,
- (void *)addr, target, CALL_INSN_SIZE);
- return CALL_INSN_SIZE;
-}
-
#ifdef CONFIG_PARAVIRT_XXL
DEFINE_ASM_FUNC(_paravirt_ident_64, "mov %rdi, %rax", .text);
DEFINE_ASM_FUNC(pv_native_save_fl, "pushf; pop %rax", .noinstr.text);
@@ -67,28 +59,6 @@ void __init native_pv_lock_init(void)
static_branch_disable(&virt_spin_lock_key);
}
-unsigned int paravirt_patch(u8 type, void *insn_buff, unsigned long addr,
- unsigned int len)
-{
- /*
- * Neat trick to map patch type back to the call within the
- * corresponding structure.
- */
- void *opfunc = *((void **)&pv_ops + type);
- unsigned ret;
-
- if (opfunc == NULL)
- /* If there's no function, patch it with x86_BUG() */
- ret = paravirt_patch_call(insn_buff, x86_BUG, addr, len);
- else if (opfunc == x86_nop)
- ret = 0;
- else
- /* Otherwise call the function. */
- ret = paravirt_patch_call(insn_buff, opfunc, addr, len);
-
- return ret;
-}
-
struct static_key paravirt_steal_enabled;
struct static_key paravirt_steal_rq_enabled;
@@ -258,19 +258,6 @@ SECTIONS
}
#endif
- /*
- * start address and size of operations which during runtime
- * can be patched with virtualization friendly instructions or
- * baremetal native ones. Think page table operations.
- * Details in paravirt_types.h
- */
- . = ALIGN(8);
- .parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) {
- __parainstructions = .;
- *(.parainstructions)
- __parainstructions_end = .;
- }
-
#ifdef CONFIG_RETPOLINE
/*
* List of instructions that call/jmp/jcc to retpoline thunks
@@ -66,7 +66,7 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = {
[S_REL] =
"^(__init_(begin|end)|"
"__x86_cpu_dev_(start|end)|"
- "(__parainstructions|__alt_instructions)(_end)?|"
+ "__alt_instructions(_end)?|"
"(__iommu_table|__apicdrivers|__smp_locks)(_end)?|"
"__(start|end)_pci_.*|"
#if CONFIG_FW_LOADER