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-rw-r--r--arch/x86/include/asm/cpufeatures.h2
-rw-r--r--arch/x86/include/asm/nospec-branch.h12
-rw-r--r--arch/x86/kernel/alternative.c8
-rw-r--r--arch/x86/kernel/cpu/bugs.c29
-rw-r--r--arch/x86/lib/retpoline.S2
-rw-r--r--arch/x86/net/bpf_jit_comp.c2
-rw-r--r--tools/arch/x86/include/asm/cpufeatures.h2
7 files changed, 32 insertions, 25 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 6db4e2932b3d..65d147974f8d 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -204,7 +204,7 @@
/* FREE! ( 7*32+10) */
#define X86_FEATURE_PTI ( 7*32+11) /* Kernel Page Table Isolation enabled */
#define X86_FEATURE_RETPOLINE ( 7*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */
-#define X86_FEATURE_RETPOLINE_AMD ( 7*32+13) /* "" AMD Retpoline mitigation for Spectre variant 2 */
+#define X86_FEATURE_RETPOLINE_LFENCE ( 7*32+13) /* "" Use LFENCE for Spectre variant 2 */
#define X86_FEATURE_INTEL_PPIN ( 7*32+14) /* Intel Processor Inventory Number */
#define X86_FEATURE_CDP_L2 ( 7*32+15) /* Code and Data Prioritization L2 */
#define X86_FEATURE_MSR_SPEC_CTRL ( 7*32+16) /* "" MSR SPEC_CTRL is implemented */
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index cc74dc584836..c91d97bee237 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -84,7 +84,7 @@
#ifdef CONFIG_RETPOLINE
ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), \
__stringify(jmp __x86_indirect_thunk_\reg), X86_FEATURE_RETPOLINE, \
- __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), X86_FEATURE_RETPOLINE_AMD
+ __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), X86_FEATURE_RETPOLINE_LFENCE
#else
jmp *%\reg
#endif
@@ -94,7 +94,7 @@
#ifdef CONFIG_RETPOLINE
ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; call *%\reg), \
__stringify(call __x86_indirect_thunk_\reg), X86_FEATURE_RETPOLINE, \
- __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; call *%\reg), X86_FEATURE_RETPOLINE_AMD
+ __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; call *%\reg), X86_FEATURE_RETPOLINE_LFENCE
#else
call *%\reg
#endif
@@ -146,7 +146,7 @@ extern retpoline_thunk_t __x86_indirect_thunk_array[];
"lfence;\n" \
ANNOTATE_RETPOLINE_SAFE \
"call *%[thunk_target]\n", \
- X86_FEATURE_RETPOLINE_AMD)
+ X86_FEATURE_RETPOLINE_LFENCE)
# define THUNK_TARGET(addr) [thunk_target] "r" (addr)
@@ -176,7 +176,7 @@ extern retpoline_thunk_t __x86_indirect_thunk_array[];
"lfence;\n" \
ANNOTATE_RETPOLINE_SAFE \
"call *%[thunk_target]\n", \
- X86_FEATURE_RETPOLINE_AMD)
+ X86_FEATURE_RETPOLINE_LFENCE)
# define THUNK_TARGET(addr) [thunk_target] "rm" (addr)
#endif
@@ -188,8 +188,8 @@ extern retpoline_thunk_t __x86_indirect_thunk_array[];
/* The Spectre V2 mitigation variants */
enum spectre_v2_mitigation {
SPECTRE_V2_NONE,
- SPECTRE_V2_RETPOLINE_GENERIC,
- SPECTRE_V2_RETPOLINE_AMD,
+ SPECTRE_V2_RETPOLINE,
+ SPECTRE_V2_LFENCE,
SPECTRE_V2_IBRS_ENHANCED,
};
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 5007c3ffe96f..b4470eabf151 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -389,7 +389,7 @@ static int emit_indirect(int op, int reg, u8 *bytes)
*
* CALL *%\reg
*
- * It also tries to inline spectre_v2=retpoline,amd when size permits.
+ * It also tries to inline spectre_v2=retpoline,lfence when size permits.
*/
static int patch_retpoline(void *addr, struct insn *insn, u8 *bytes)
{
@@ -407,7 +407,7 @@ static int patch_retpoline(void *addr, struct insn *insn, u8 *bytes)
BUG_ON(reg == 4);
if (cpu_feature_enabled(X86_FEATURE_RETPOLINE) &&
- !cpu_feature_enabled(X86_FEATURE_RETPOLINE_AMD))
+ !cpu_feature_enabled(X86_FEATURE_RETPOLINE_LFENCE))
return -1;
op = insn->opcode.bytes[0];
@@ -438,9 +438,9 @@ static int patch_retpoline(void *addr, struct insn *insn, u8 *bytes)
}
/*
- * For RETPOLINE_AMD: prepend the indirect CALL/JMP with an LFENCE.
+ * For RETPOLINE_LFENCE: prepend the indirect CALL/JMP with an LFENCE.
*/
- if (cpu_feature_enabled(X86_FEATURE_RETPOLINE_AMD)) {
+ if (cpu_feature_enabled(X86_FEATURE_RETPOLINE_LFENCE)) {
bytes[i++] = 0x0f;
bytes[i++] = 0xae;
bytes[i++] = 0xe8; /* LFENCE */
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 1c1f218a701d..e3bb8afc6768 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -664,7 +664,7 @@ enum spectre_v2_mitigation_cmd {
SPECTRE_V2_CMD_FORCE,
SPECTRE_V2_CMD_RETPOLINE,
SPECTRE_V2_CMD_RETPOLINE_GENERIC,
- SPECTRE_V2_CMD_RETPOLINE_AMD,
+ SPECTRE_V2_CMD_RETPOLINE_LFENCE,
};
enum spectre_v2_user_cmd {
@@ -824,8 +824,8 @@ set_mode:
static const char * const spectre_v2_strings[] = {
[SPECTRE_V2_NONE] = "Vulnerable",
- [SPECTRE_V2_RETPOLINE_GENERIC] = "Mitigation: Full generic retpoline",
- [SPECTRE_V2_RETPOLINE_AMD] = "Mitigation: Full AMD retpoline",
+ [SPECTRE_V2_RETPOLINE] = "Mitigation: Retpolines",
+ [SPECTRE_V2_LFENCE] = "Mitigation: LFENCE",
[SPECTRE_V2_IBRS_ENHANCED] = "Mitigation: Enhanced IBRS",
};
@@ -837,7 +837,8 @@ static const struct {
{ "off", SPECTRE_V2_CMD_NONE, false },
{ "on", SPECTRE_V2_CMD_FORCE, true },
{ "retpoline", SPECTRE_V2_CMD_RETPOLINE, false },
- { "retpoline,amd", SPECTRE_V2_CMD_RETPOLINE_AMD, false },
+ { "retpoline,amd", SPECTRE_V2_CMD_RETPOLINE_LFENCE, false },
+ { "retpoline,lfence", SPECTRE_V2_CMD_RETPOLINE_LFENCE, false },
{ "retpoline,generic", SPECTRE_V2_CMD_RETPOLINE_GENERIC, false },
{ "auto", SPECTRE_V2_CMD_AUTO, false },
};
@@ -875,13 +876,19 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
}
if ((cmd == SPECTRE_V2_CMD_RETPOLINE ||
- cmd == SPECTRE_V2_CMD_RETPOLINE_AMD ||
+ cmd == SPECTRE_V2_CMD_RETPOLINE_LFENCE ||
cmd == SPECTRE_V2_CMD_RETPOLINE_GENERIC) &&
!IS_ENABLED(CONFIG_RETPOLINE)) {
pr_err("%s selected but not compiled in. Switching to AUTO select\n", mitigation_options[i].option);
return SPECTRE_V2_CMD_AUTO;
}
+ if ((cmd == SPECTRE_V2_CMD_RETPOLINE_LFENCE) &&
+ !boot_cpu_has(X86_FEATURE_LFENCE_RDTSC)) {
+ pr_err("%s selected, but CPU doesn't have a serializing LFENCE. Switching to AUTO select\n", mitigation_options[i].option);
+ return SPECTRE_V2_CMD_AUTO;
+ }
+
spec_v2_print_cond(mitigation_options[i].option,
mitigation_options[i].secure);
return cmd;
@@ -916,9 +923,9 @@ static void __init spectre_v2_select_mitigation(void)
if (IS_ENABLED(CONFIG_RETPOLINE))
goto retpoline_auto;
break;
- case SPECTRE_V2_CMD_RETPOLINE_AMD:
+ case SPECTRE_V2_CMD_RETPOLINE_LFENCE:
if (IS_ENABLED(CONFIG_RETPOLINE))
- goto retpoline_amd;
+ goto retpoline_lfence;
break;
case SPECTRE_V2_CMD_RETPOLINE_GENERIC:
if (IS_ENABLED(CONFIG_RETPOLINE))
@@ -935,17 +942,17 @@ static void __init spectre_v2_select_mitigation(void)
retpoline_auto:
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
- retpoline_amd:
+ retpoline_lfence:
if (!boot_cpu_has(X86_FEATURE_LFENCE_RDTSC)) {
pr_err("Spectre mitigation: LFENCE not serializing, switching to generic retpoline\n");
goto retpoline_generic;
}
- mode = SPECTRE_V2_RETPOLINE_AMD;
- setup_force_cpu_cap(X86_FEATURE_RETPOLINE_AMD);
+ mode = SPECTRE_V2_LFENCE;
+ setup_force_cpu_cap(X86_FEATURE_RETPOLINE_LFENCE);
setup_force_cpu_cap(X86_FEATURE_RETPOLINE);
} else {
retpoline_generic:
- mode = SPECTRE_V2_RETPOLINE_GENERIC;
+ mode = SPECTRE_V2_RETPOLINE;
setup_force_cpu_cap(X86_FEATURE_RETPOLINE);
}
diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S
index 89b3fb244e15..afbdda539b80 100644
--- a/arch/x86/lib/retpoline.S
+++ b/arch/x86/lib/retpoline.S
@@ -34,7 +34,7 @@ SYM_INNER_LABEL(__x86_indirect_thunk_\reg, SYM_L_GLOBAL)
ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), \
__stringify(RETPOLINE \reg), X86_FEATURE_RETPOLINE, \
- __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg; int3), X86_FEATURE_RETPOLINE_AMD
+ __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg; int3), X86_FEATURE_RETPOLINE_LFENCE
.endm
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 2b1e266ff95c..0ecb140864b2 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -394,7 +394,7 @@ static void emit_indirect_jump(u8 **pprog, int reg, u8 *ip)
u8 *prog = *pprog;
#ifdef CONFIG_RETPOLINE
- if (cpu_feature_enabled(X86_FEATURE_RETPOLINE_AMD)) {
+ if (cpu_feature_enabled(X86_FEATURE_RETPOLINE_LFENCE)) {
EMIT_LFENCE();
EMIT2(0xFF, 0xE0 + reg);
} else if (cpu_feature_enabled(X86_FEATURE_RETPOLINE)) {
diff --git a/tools/arch/x86/include/asm/cpufeatures.h b/tools/arch/x86/include/asm/cpufeatures.h
index 6db4e2932b3d..ab4e53715d8a 100644
--- a/tools/arch/x86/include/asm/cpufeatures.h
+++ b/tools/arch/x86/include/asm/cpufeatures.h
@@ -204,7 +204,7 @@
/* FREE! ( 7*32+10) */
#define X86_FEATURE_PTI ( 7*32+11) /* Kernel Page Table Isolation enabled */
#define X86_FEATURE_RETPOLINE ( 7*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */
-#define X86_FEATURE_RETPOLINE_AMD ( 7*32+13) /* "" AMD Retpoline mitigation for Spectre variant 2 */
+#define X86_FEATURE_RETPOLINE_LFENCE ( 7*32+13) /* "" Use LFENCEs for Spectre variant 2 */
#define X86_FEATURE_INTEL_PPIN ( 7*32+14) /* Intel Processor Inventory Number */
#define X86_FEATURE_CDP_L2 ( 7*32+15) /* Code and Data Prioritization L2 */
#define X86_FEATURE_MSR_SPEC_CTRL ( 7*32+16) /* "" MSR SPEC_CTRL is implemented */