x86/boot: Add a bunch of PIC aliases

Add aliases for all the data objects that the startup code references -
this is needed so that this code can be moved into its own confined area
where it can only access symbols that have a __pi_ prefix.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20250504095230.2932860-39-ardb+git@google.com

diff --git a/arch/x86/coco/core.c b/arch/x86/coco/core.c
index 9a0ddda3aa69760aea1c8435936325f970b05ba4..d4610af68114348499ebd54a4612612dd20e97ba 100644 (file)
--- a/arch/x86/coco/core.c
+++ b/arch/x86/coco/core.c
@@ -18,7 +18,9 @@
 #include <asm/processor.h>
 
 enum cc_vendor cc_vendor __ro_after_init = CC_VENDOR_NONE;
+SYM_PIC_ALIAS(cc_vendor);
 u64 cc_mask __ro_after_init;
+SYM_PIC_ALIAS(cc_mask);
 
 static struct cc_attr_flags {
        __u64 host_sev_snp      : 1,

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 12126adbc3a9a7e2b767e024ececd3940098f3e8..f0f85482a73b4c9fea9cb28cbf46b86aa51ac98f 100644 (file)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -242,6 +242,7 @@ DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
 #endif
 } };
 EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
+SYM_PIC_ALIAS(gdt_page);
 
 #ifdef CONFIG_X86_64
 static int __init x86_nopcid_setup(char *s)

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 29226f3ac06477e3c348c5f899d8fe9426b9b0e9..510fb41f55fce7521943f6c0f065509b7cb726e0 100644 (file)
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -48,6 +48,7 @@
  */
 extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD];
 unsigned int __initdata next_early_pgt;
+SYM_PIC_ALIAS(next_early_pgt);
 pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX);
 
 #ifdef CONFIG_X86_5LEVEL
@@ -61,10 +62,13 @@ EXPORT_SYMBOL(ptrs_per_p4d);
 #ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT
 unsigned long page_offset_base __ro_after_init = __PAGE_OFFSET_BASE_L4;
 EXPORT_SYMBOL(page_offset_base);
+SYM_PIC_ALIAS(page_offset_base);
 unsigned long vmalloc_base __ro_after_init = __VMALLOC_BASE_L4;
 EXPORT_SYMBOL(vmalloc_base);
+SYM_PIC_ALIAS(vmalloc_base);
 unsigned long vmemmap_base __ro_after_init = __VMEMMAP_BASE_L4;
 EXPORT_SYMBOL(vmemmap_base);
+SYM_PIC_ALIAS(vmemmap_base);
 #endif
 
 /* Wipe all early page tables except for the kernel symbol map */

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index fefe2a25cf025415c1d202081c1616e1182abbad..069420853304fbaa16bd484d0e4875b8a26851dc 100644 (file)
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -573,6 +573,7 @@ SYM_CODE_START_NOALIGN(vc_no_ghcb)
        /* Pure iret required here - don't use INTERRUPT_RETURN */
        iretq
 SYM_CODE_END(vc_no_ghcb)
+SYM_PIC_ALIAS(vc_no_ghcb);
 #endif
 
 #ifdef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION
@@ -604,10 +605,12 @@ SYM_DATA_START_PTI_ALIGNED(early_top_pgt)
        .quad   level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
        .fill   PTI_USER_PGD_FILL,8,0
 SYM_DATA_END(early_top_pgt)
+SYM_PIC_ALIAS(early_top_pgt)
 
 SYM_DATA_START_PAGE_ALIGNED(early_dynamic_pgts)
        .fill   512*EARLY_DYNAMIC_PAGE_TABLES,8,0
 SYM_DATA_END(early_dynamic_pgts)
+SYM_PIC_ALIAS(early_dynamic_pgts);
 
 SYM_DATA(early_recursion_flag, .long 0)
 
@@ -651,6 +654,7 @@ SYM_DATA_START_PAGE_ALIGNED(level4_kernel_pgt)
        .fill   511,8,0
        .quad   level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
 SYM_DATA_END(level4_kernel_pgt)
+SYM_PIC_ALIAS(level4_kernel_pgt)
 #endif
 
 SYM_DATA_START_PAGE_ALIGNED(level3_kernel_pgt)
@@ -659,6 +663,7 @@ SYM_DATA_START_PAGE_ALIGNED(level3_kernel_pgt)
        .quad   level2_kernel_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
        .quad   level2_fixmap_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
 SYM_DATA_END(level3_kernel_pgt)
+SYM_PIC_ALIAS(level3_kernel_pgt)
 
 SYM_DATA_START_PAGE_ALIGNED(level2_kernel_pgt)
        /*
@@ -676,6 +681,7 @@ SYM_DATA_START_PAGE_ALIGNED(level2_kernel_pgt)
         */
        PMDS(0, __PAGE_KERNEL_LARGE_EXEC, KERNEL_IMAGE_SIZE/PMD_SIZE)
 SYM_DATA_END(level2_kernel_pgt)
+SYM_PIC_ALIAS(level2_kernel_pgt)
 
 SYM_DATA_START_PAGE_ALIGNED(level2_fixmap_pgt)
        .fill   (512 - 4 - FIXMAP_PMD_NUM),8,0
@@ -688,6 +694,7 @@ SYM_DATA_START_PAGE_ALIGNED(level2_fixmap_pgt)
        /* 6 MB reserved space + a 2MB hole */
        .fill   4,8,0
 SYM_DATA_END(level2_fixmap_pgt)
+SYM_PIC_ALIAS(level2_fixmap_pgt)
 
 SYM_DATA_START_PAGE_ALIGNED(level1_fixmap_pgt)
        .rept (FIXMAP_PMD_NUM)
@@ -703,6 +710,7 @@ SYM_DATA(smpboot_control,           .long 0)
        .align 16
 /* This must match the first entry in level2_kernel_pgt */
 SYM_DATA(phys_base, .quad 0x0)
+SYM_PIC_ALIAS(phys_base);
 EXPORT_SYMBOL(phys_base)
 
 #include "../xen/xen-head.S"

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 9d2a13b37833c9687eaf5dc51a8d3c9c1c07dfce..e0cf1595a0ab040674a2b62034b04db195584718 100644 (file)
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -134,6 +134,7 @@ struct ist_info ist_info;
 
 struct cpuinfo_x86 boot_cpu_data __read_mostly;
 EXPORT_SYMBOL(boot_cpu_data);
+SYM_PIC_ALIAS(boot_cpu_data);
 
 #if !defined(CONFIG_X86_PAE) || defined(CONFIG_X86_64)
 __visible unsigned long mmu_cr4_features __ro_after_init;

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index ccdc45e5b75961711580f62cb2a73f48c1c433c5..9340c74b680d0ef73844dc979889833f02bcf37e 100644 (file)
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -79,11 +79,13 @@ const_cpu_current_top_of_stack = cpu_current_top_of_stack;
 #define BSS_DECRYPTED                                          \
        . = ALIGN(PMD_SIZE);                                    \
        __start_bss_decrypted = .;                              \
+       __pi___start_bss_decrypted = .;                         \
        *(.bss..decrypted);                                     \
        . = ALIGN(PAGE_SIZE);                                   \
        __start_bss_decrypted_unused = .;                       \
        . = ALIGN(PMD_SIZE);                                    \
        __end_bss_decrypted = .;                                \
+       __pi___end_bss_decrypted = .;                           \
 
 #else
 
@@ -128,6 +130,7 @@ SECTIONS
        /* Text and read-only data */
        .text :  AT(ADDR(.text) - LOAD_OFFSET) {
                _text = .;
+               __pi__text = .;
                _stext = .;
                ALIGN_ENTRY_TEXT_BEGIN
                *(.text..__x86.rethunk_untrain)
@@ -391,6 +394,7 @@ SECTIONS
 
        . = ALIGN(PAGE_SIZE);           /* keep VO_INIT_SIZE page aligned */
        _end = .;
+       __pi__end = .;
 
 #ifdef CONFIG_AMD_MEM_ENCRYPT
        /*

diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index 0ae2e1712e2eaeba27c9371e7b154266873b2b1f..12a23fa7c44c59664bffb541f1e428768fa50549 100644 (file)
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -41,6 +41,7 @@ SYM_FUNC_END(__memcpy)
 EXPORT_SYMBOL(__memcpy)
 
 SYM_FUNC_ALIAS_MEMFUNC(memcpy, __memcpy)
+SYM_PIC_ALIAS(memcpy)
 EXPORT_SYMBOL(memcpy)
 
 SYM_FUNC_START_LOCAL(memcpy_orig)

diff --git a/arch/x86/lib/memset_64.S b/arch/x86/lib/memset_64.S
index d66b710d628f886587dcb4f01c37e7976794536c..fb5a03cf5ab7e5e4a20ff230b883b983f1cb93db 100644 (file)
--- a/arch/x86/lib/memset_64.S
+++ b/arch/x86/lib/memset_64.S
@@ -42,6 +42,7 @@ SYM_FUNC_END(__memset)
 EXPORT_SYMBOL(__memset)
 
 SYM_FUNC_ALIAS_MEMFUNC(memset, __memset)
+SYM_PIC_ALIAS(memset)
 EXPORT_SYMBOL(memset)
 
 SYM_FUNC_START_LOCAL(memset_orig)

diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S
index a26c43abd47d8dfc8ff1c4ac94da6e76e466beea..9f3116609c8c74fefb0cced5d69c1587a11cdf12 100644 (file)
--- a/arch/x86/lib/retpoline.S
+++ b/arch/x86/lib/retpoline.S
@@ -40,6 +40,7 @@ SYM_INNER_LABEL(__x86_indirect_thunk_\reg, SYM_L_GLOBAL)
        ALTERNATIVE_2 __stringify(RETPOLINE \reg), \
                      __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg; int3), X86_FEATURE_RETPOLINE_LFENCE, \
                      __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), ALT_NOT(X86_FEATURE_RETPOLINE)
+SYM_PIC_ALIAS(__x86_indirect_thunk_\reg)
 
 .endm
 
@@ -394,6 +395,7 @@ SYM_CODE_START(__x86_return_thunk)
 #endif
        int3
 SYM_CODE_END(__x86_return_thunk)
+SYM_PIC_ALIAS(__x86_return_thunk)
 EXPORT_SYMBOL(__x86_return_thunk)
 
 #endif /* CONFIG_MITIGATION_RETHUNK */

diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c
index 7490ff6d83b1bcf4df2c6d7137035f8e7873d5cb..faf3a13fb6ba0b19e2e8f6ee9c21133138acf404 100644 (file)
--- a/arch/x86/mm/mem_encrypt_amd.c
+++ b/arch/x86/mm/mem_encrypt_amd.c
@@ -40,7 +40,9 @@
  * section is later cleared.
  */
 u64 sme_me_mask __section(".data") = 0;
+SYM_PIC_ALIAS(sme_me_mask);
 u64 sev_status __section(".data") = 0;
+SYM_PIC_ALIAS(sev_status);
 u64 sev_check_data __section(".data") = 0;
 EXPORT_SYMBOL(sme_me_mask);
 

diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index f7ae44d3dd9e0136066dea955f2718968a616463..e62af72923e8f531d1752137f7a166dfc5f0a5f6 100644 (file)
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -10,6 +10,7 @@
 #ifdef CONFIG_DYNAMIC_PHYSICAL_MASK
 phys_addr_t physical_mask __ro_after_init = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
 EXPORT_SYMBOL(physical_mask);
+SYM_PIC_ALIAS(physical_mask);
 #endif
 
 pgtable_t pte_alloc_one(struct mm_struct *mm)

diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 3ce7b54003c229a1c300584f550be072640cb488..331b9a7444102359e85b887b2c584686ddae8108 100644 (file)
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -842,12 +842,14 @@ int arch_decode_hint_reg(u8 sp_reg, int *base)
 
 bool arch_is_retpoline(struct symbol *sym)
 {
-       return !strncmp(sym->name, "__x86_indirect_", 15);
+       return !strncmp(sym->name, "__x86_indirect_", 15) ||
+              !strncmp(sym->name, "__pi___x86_indirect_", 20);
 }
 
 bool arch_is_rethunk(struct symbol *sym)
 {
-       return !strcmp(sym->name, "__x86_return_thunk");
+       return !strcmp(sym->name, "__x86_return_thunk") ||
+              !strcmp(sym->name, "__pi___x86_return_thunk");
 }
 
 bool arch_is_embedded_insn(struct symbol *sym)