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-rw-r--r--arch/x86/boot/compressed/ident_map_64.c13
-rw-r--r--arch/x86/entry/entry_64.S9
-rw-r--r--arch/x86/include/asm/cpufeatures.h2
-rw-r--r--arch/x86/include/asm/msr-index.h9
-rw-r--r--arch/x86/include/asm/setup.h3
-rw-r--r--arch/x86/include/uapi/asm/bootparam.h2
-rw-r--r--arch/x86/kernel/acpi/cppc.c10
-rw-r--r--arch/x86/kernel/cpu/bugs.c33
-rw-r--r--arch/x86/kernel/cpu/common.c1
-rw-r--r--arch/x86/kernel/cpu/scattered.c1
-rw-r--r--arch/x86/kernel/head64.c4
-rw-r--r--arch/x86/kernel/relocate_kernel_32.S25
-rw-r--r--arch/x86/kernel/relocate_kernel_64.S23
-rw-r--r--arch/x86/kernel/vmlinux.lds.S2
-rw-r--r--arch/x86/xen/enlighten_pv.c8
-rw-r--r--arch/x86/xen/xen-head.S10
16 files changed, 123 insertions, 32 deletions
diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c
index 44c350d627c7..d4a314cc50d6 100644
--- a/arch/x86/boot/compressed/ident_map_64.c
+++ b/arch/x86/boot/compressed/ident_map_64.c
@@ -110,6 +110,7 @@ void kernel_add_identity_map(unsigned long start, unsigned long end)
void initialize_identity_maps(void *rmode)
{
unsigned long cmdline;
+ struct setup_data *sd;
/* Exclude the encryption mask from __PHYSICAL_MASK */
physical_mask &= ~sme_me_mask;
@@ -163,6 +164,18 @@ void initialize_identity_maps(void *rmode)
cmdline = get_cmd_line_ptr();
kernel_add_identity_map(cmdline, cmdline + COMMAND_LINE_SIZE);
+ /*
+ * Also map the setup_data entries passed via boot_params in case they
+ * need to be accessed by uncompressed kernel via the identity mapping.
+ */
+ sd = (struct setup_data *)boot_params->hdr.setup_data;
+ while (sd) {
+ unsigned long sd_addr = (unsigned long)sd;
+
+ kernel_add_identity_map(sd_addr, sd_addr + sizeof(*sd) + sd->len);
+ sd = (struct setup_data *)sd->next;
+ }
+
sev_prep_identity_maps(top_level_pgt);
/* Load the new page-table. */
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index a4ba162e52c3..285e043a3e40 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -328,6 +328,8 @@ SYM_CODE_END(ret_from_fork)
SYM_CODE_START_LOCAL(xen_error_entry)
UNWIND_HINT_FUNC
+ PUSH_AND_CLEAR_REGS save_ret=1
+ ENCODE_FRAME_POINTER 8
UNTRAIN_RET
RET
SYM_CODE_END(xen_error_entry)
@@ -339,9 +341,6 @@ SYM_CODE_END(xen_error_entry)
*/
.macro idtentry_body cfunc has_error_code:req
- PUSH_AND_CLEAR_REGS
- ENCODE_FRAME_POINTER
-
/*
* Call error_entry() and switch to the task stack if from userspace.
*
@@ -1042,6 +1041,10 @@ SYM_CODE_END(paranoid_exit)
*/
SYM_CODE_START_LOCAL(error_entry)
UNWIND_HINT_FUNC
+
+ PUSH_AND_CLEAR_REGS save_ret=1
+ ENCODE_FRAME_POINTER 8
+
testb $3, CS+8(%rsp)
jz .Lerror_kernelspace
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 7e8099fd5ec1..00f5227c8459 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -297,7 +297,7 @@
#define X86_FEATURE_SGX1 (11*32+ 8) /* "" Basic SGX */
#define X86_FEATURE_SGX2 (11*32+ 9) /* "" SGX Enclave Dynamic Memory Management (EDMM) */
#define X86_FEATURE_ENTRY_IBPB (11*32+10) /* "" Issue an IBPB on kernel entry */
-/* FREE! (11*32+11) */
+#define X86_FEATURE_RRSBA_CTRL (11*32+11) /* "" RET prediction control */
#define X86_FEATURE_RETPOLINE (11*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */
#define X86_FEATURE_RETPOLINE_LFENCE (11*32+13) /* "" Use LFENCE for Spectre variant 2 */
#define X86_FEATURE_RETHUNK (11*32+14) /* "" Use REturn THUNK */
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 7b411d9a6efb..cc615be27a54 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -51,6 +51,8 @@
#define SPEC_CTRL_STIBP BIT(SPEC_CTRL_STIBP_SHIFT) /* STIBP mask */
#define SPEC_CTRL_SSBD_SHIFT 2 /* Speculative Store Bypass Disable bit */
#define SPEC_CTRL_SSBD BIT(SPEC_CTRL_SSBD_SHIFT) /* Speculative Store Bypass Disable */
+#define SPEC_CTRL_RRSBA_DIS_S_SHIFT 6 /* Disable RRSBA behavior */
+#define SPEC_CTRL_RRSBA_DIS_S BIT(SPEC_CTRL_RRSBA_DIS_S_SHIFT)
#define MSR_IA32_PRED_CMD 0x00000049 /* Prediction Command */
#define PRED_CMD_IBPB BIT(0) /* Indirect Branch Prediction Barrier */
@@ -141,6 +143,13 @@
* bit available to control VERW
* behavior.
*/
+#define ARCH_CAP_RRSBA BIT(19) /*
+ * Indicates RET may use predictors
+ * other than the RSB. With eIBRS
+ * enabled predictions in kernel mode
+ * are restricted to targets in
+ * kernel.
+ */
#define MSR_IA32_FLUSH_CMD 0x0000010b
#define L1D_FLUSH BIT(0) /*
diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
index f8b9ee97a891..f37cbff7354c 100644
--- a/arch/x86/include/asm/setup.h
+++ b/arch/x86/include/asm/setup.h
@@ -120,6 +120,9 @@ void *extend_brk(size_t size, size_t align);
static char __brk_##name[size]
extern void probe_roms(void);
+
+void clear_bss(void);
+
#ifdef __i386__
asmlinkage void __init i386_start_kernel(void);
diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index bea5cdcdf532..e02a8a8ef23c 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -15,7 +15,7 @@
#define SETUP_INDIRECT (1<<31)
/* SETUP_INDIRECT | max(SETUP_*) */
-#define SETUP_TYPE_MAX (SETUP_INDIRECT | SETUP_JAILHOUSE)
+#define SETUP_TYPE_MAX (SETUP_INDIRECT | SETUP_CC_BLOB)
/* ram_size flags */
#define RAMDISK_IMAGE_START_MASK 0x07FF
diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c
index 8b8cbf22461a..734b96454896 100644
--- a/arch/x86/kernel/acpi/cppc.c
+++ b/arch/x86/kernel/acpi/cppc.c
@@ -11,6 +11,16 @@
/* Refer to drivers/acpi/cppc_acpi.c for the description of functions */
+bool cpc_supported_by_cpu(void)
+{
+ switch (boot_cpu_data.x86_vendor) {
+ case X86_VENDOR_AMD:
+ case X86_VENDOR_HYGON:
+ return boot_cpu_has(X86_FEATURE_CPPC);
+ }
+ return false;
+}
+
bool cpc_ffh_supported(void)
{
return true;
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index cf08a1b8f3c7..0dd04713434b 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -865,7 +865,10 @@ static void __init retbleed_select_mitigation(void)
break;
case RETBLEED_CMD_IBPB:
- if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY)) {
+ if (!boot_cpu_has(X86_FEATURE_IBPB)) {
+ pr_err("WARNING: CPU does not support IBPB.\n");
+ goto do_cmd_auto;
+ } else if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY)) {
retbleed_mitigation = RETBLEED_MITIGATION_IBPB;
} else {
pr_err("WARNING: kernel not compiled with CPU_IBPB_ENTRY.\n");
@@ -880,7 +883,7 @@ do_cmd_auto:
boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
if (IS_ENABLED(CONFIG_CPU_UNRET_ENTRY))
retbleed_mitigation = RETBLEED_MITIGATION_UNRET;
- else if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY))
+ else if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY) && boot_cpu_has(X86_FEATURE_IBPB))
retbleed_mitigation = RETBLEED_MITIGATION_IBPB;
}
@@ -1315,6 +1318,22 @@ static enum spectre_v2_mitigation __init spectre_v2_select_retpoline(void)
return SPECTRE_V2_RETPOLINE;
}
+/* Disable in-kernel use of non-RSB RET predictors */
+static void __init spec_ctrl_disable_kernel_rrsba(void)
+{
+ u64 ia32_cap;
+
+ if (!boot_cpu_has(X86_FEATURE_RRSBA_CTRL))
+ return;
+
+ ia32_cap = x86_read_arch_cap_msr();
+
+ if (ia32_cap & ARCH_CAP_RRSBA) {
+ x86_spec_ctrl_base |= SPEC_CTRL_RRSBA_DIS_S;
+ write_spec_ctrl_current(x86_spec_ctrl_base, true);
+ }
+}
+
static void __init spectre_v2_select_mitigation(void)
{
enum spectre_v2_mitigation_cmd cmd = spectre_v2_parse_cmdline();
@@ -1409,6 +1428,16 @@ static void __init spectre_v2_select_mitigation(void)
break;
}
+ /*
+ * Disable alternate RSB predictions in kernel when indirect CALLs and
+ * JMPs gets protection against BHI and Intramode-BTI, but RET
+ * prediction from a non-RSB predictor is still a risk.
+ */
+ if (mode == SPECTRE_V2_EIBRS_LFENCE ||
+ mode == SPECTRE_V2_EIBRS_RETPOLINE ||
+ mode == SPECTRE_V2_RETPOLINE)
+ spec_ctrl_disable_kernel_rrsba();
+
spectre_v2_enabled = mode;
pr_info("%s\n", spectre_v2_strings[mode]);
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 02ba27355b04..736262a76a12 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1242,6 +1242,7 @@ static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
VULNBL_INTEL_STEPPINGS(SKYLAKE, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED),
VULNBL_INTEL_STEPPINGS(KABYLAKE_L, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED),
VULNBL_INTEL_STEPPINGS(KABYLAKE, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED),
+ VULNBL_INTEL_STEPPINGS(CANNONLAKE_L, X86_STEPPING_ANY, RETBLEED),
VULNBL_INTEL_STEPPINGS(ICELAKE_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED),
VULNBL_INTEL_STEPPINGS(ICELAKE_D, X86_STEPPING_ANY, MMIO),
VULNBL_INTEL_STEPPINGS(ICELAKE_X, X86_STEPPING_ANY, MMIO),
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index dbaa8326d6f2..fd44b54c90d5 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -27,6 +27,7 @@ static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_APERFMPERF, CPUID_ECX, 0, 0x00000006, 0 },
{ X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 },
{ X86_FEATURE_INTEL_PPIN, CPUID_EBX, 0, 0x00000007, 1 },
+ { X86_FEATURE_RRSBA_CTRL, CPUID_EDX, 2, 0x00000007, 2 },
{ X86_FEATURE_CQM_LLC, CPUID_EDX, 1, 0x0000000f, 0 },
{ X86_FEATURE_CQM_OCCUP_LLC, CPUID_EDX, 0, 0x0000000f, 1 },
{ X86_FEATURE_CQM_MBM_TOTAL, CPUID_EDX, 1, 0x0000000f, 1 },
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index bd4a34100ed0..6a3cfaf6b72a 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -426,10 +426,12 @@ void __init do_early_exception(struct pt_regs *regs, int trapnr)
/* Don't add a printk in there. printk relies on the PDA which is not initialized
yet. */
-static void __init clear_bss(void)
+void __init clear_bss(void)
{
memset(__bss_start, 0,
(unsigned long) __bss_stop - (unsigned long) __bss_start);
+ memset(__brk_base, 0,
+ (unsigned long) __brk_limit - (unsigned long) __brk_base);
}
static unsigned long get_cmd_line_ptr(void)
diff --git a/arch/x86/kernel/relocate_kernel_32.S b/arch/x86/kernel/relocate_kernel_32.S
index fcc8a7699103..c7c4b1917336 100644
--- a/arch/x86/kernel/relocate_kernel_32.S
+++ b/arch/x86/kernel/relocate_kernel_32.S
@@ -7,10 +7,12 @@
#include <linux/linkage.h>
#include <asm/page_types.h>
#include <asm/kexec.h>
+#include <asm/nospec-branch.h>
#include <asm/processor-flags.h>
/*
- * Must be relocatable PIC code callable as a C function
+ * Must be relocatable PIC code callable as a C function, in particular
+ * there must be a plain RET and not jump to return thunk.
*/
#define PTR(x) (x << 2)
@@ -91,7 +93,9 @@ SYM_CODE_START_NOALIGN(relocate_kernel)
movl %edi, %eax
addl $(identity_mapped - relocate_kernel), %eax
pushl %eax
- RET
+ ANNOTATE_UNRET_SAFE
+ ret
+ int3
SYM_CODE_END(relocate_kernel)
SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
@@ -159,12 +163,15 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
xorl %edx, %edx
xorl %esi, %esi
xorl %ebp, %ebp
- RET
+ ANNOTATE_UNRET_SAFE
+ ret
+ int3
1:
popl %edx
movl CP_PA_SWAP_PAGE(%edi), %esp
addl $PAGE_SIZE, %esp
2:
+ ANNOTATE_RETPOLINE_SAFE
call *%edx
/* get the re-entry point of the peer system */
@@ -190,7 +197,9 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
movl %edi, %eax
addl $(virtual_mapped - relocate_kernel), %eax
pushl %eax
- RET
+ ANNOTATE_UNRET_SAFE
+ ret
+ int3
SYM_CODE_END(identity_mapped)
SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
@@ -208,7 +217,9 @@ SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
popl %edi
popl %esi
popl %ebx
- RET
+ ANNOTATE_UNRET_SAFE
+ ret
+ int3
SYM_CODE_END(virtual_mapped)
/* Do the copies */
@@ -271,7 +282,9 @@ SYM_CODE_START_LOCAL_NOALIGN(swap_pages)
popl %edi
popl %ebx
popl %ebp
- RET
+ ANNOTATE_UNRET_SAFE
+ ret
+ int3
SYM_CODE_END(swap_pages)
.globl kexec_control_code_size
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
index c1d8626c53b6..4809c0dc4eb0 100644
--- a/arch/x86/kernel/relocate_kernel_64.S
+++ b/arch/x86/kernel/relocate_kernel_64.S
@@ -13,7 +13,8 @@
#include <asm/unwind_hints.h>
/*
- * Must be relocatable PIC code callable as a C function
+ * Must be relocatable PIC code callable as a C function, in particular
+ * there must be a plain RET and not jump to return thunk.
*/
#define PTR(x) (x << 3)
@@ -105,7 +106,9 @@ SYM_CODE_START_NOALIGN(relocate_kernel)
/* jump to identity mapped page */
addq $(identity_mapped - relocate_kernel), %r8
pushq %r8
- RET
+ ANNOTATE_UNRET_SAFE
+ ret
+ int3
SYM_CODE_END(relocate_kernel)
SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
@@ -200,7 +203,9 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
xorl %r14d, %r14d
xorl %r15d, %r15d
- RET
+ ANNOTATE_UNRET_SAFE
+ ret
+ int3
1:
popq %rdx
@@ -219,7 +224,9 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
call swap_pages
movq $virtual_mapped, %rax
pushq %rax
- RET
+ ANNOTATE_UNRET_SAFE
+ ret
+ int3
SYM_CODE_END(identity_mapped)
SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
@@ -241,7 +248,9 @@ SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
popq %r12
popq %rbp
popq %rbx
- RET
+ ANNOTATE_UNRET_SAFE
+ ret
+ int3
SYM_CODE_END(virtual_mapped)
/* Do the copies */
@@ -298,7 +307,9 @@ SYM_CODE_START_LOCAL_NOALIGN(swap_pages)
lea PAGE_SIZE(%rax), %rsi
jmp 0b
3:
- RET
+ ANNOTATE_UNRET_SAFE
+ ret
+ int3
SYM_CODE_END(swap_pages)
.globl kexec_control_code_size
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index c375420036fb..15f29053cec4 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -392,7 +392,7 @@ SECTIONS
__end_of_kernel_reserve = .;
. = ALIGN(PAGE_SIZE);
- .brk (NOLOAD) : AT(ADDR(.brk) - LOAD_OFFSET) {
+ .brk : AT(ADDR(.brk) - LOAD_OFFSET) {
__brk_base = .;
. += 64 * 1024; /* 64k alignment slop space */
*(.bss..brk) /* areas brk users have reserved */
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index e3297b15701c..70fb2ea85e90 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1183,15 +1183,19 @@ static void __init xen_domu_set_legacy_features(void)
extern void early_xen_iret_patch(void);
/* First C function to be called on Xen boot */
-asmlinkage __visible void __init xen_start_kernel(void)
+asmlinkage __visible void __init xen_start_kernel(struct start_info *si)
{
struct physdev_set_iopl set_iopl;
unsigned long initrd_start = 0;
int rc;
- if (!xen_start_info)
+ if (!si)
return;
+ clear_bss();
+
+ xen_start_info = si;
+
__text_gen_insn(&early_xen_iret_patch,
JMP32_INSN_OPCODE, &early_xen_iret_patch, &xen_iret,
JMP32_INSN_SIZE);
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index fa884fc73e07..ffaa62167f6e 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -49,15 +49,6 @@ SYM_CODE_START(startup_xen)
ANNOTATE_NOENDBR
cld
- /* Clear .bss */
- xor %eax,%eax
- mov $__bss_start, %rdi
- mov $__bss_stop, %rcx
- sub %rdi, %rcx
- shr $3, %rcx
- rep stosq
-
- mov %rsi, xen_start_info
mov initial_stack(%rip), %rsp
/* Set up %gs.
@@ -72,6 +63,7 @@ SYM_CODE_START(startup_xen)
cdq
wrmsr
+ mov %rsi, %rdi
call xen_start_kernel
SYM_CODE_END(startup_xen)
__FINIT
generated by cgit v1.2.3 (git 2.39.0) at 2024-07-22 17:22:45 +0300