x86/boot: Move startup code out of __head section

Move startup code out of the __head section, now that this no longer has
a special significance. Move everything into .text or .init.text as
appropriate, so that startup code is not kept around unnecessarily.

  [ bp: Fold in hunk to fix 32-bit CPU hotplug:
    Reported-by: kernel test robot <oliver.sang@intel.com>
    Closes: https://lore.kernel.org/oe-lkp/202509022207.56fd97f4-lkp@intel.com ]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20250828102202.1849035-45-ardb+git@google.com

diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index a5e002ff6bff9b95d940a96d7053f64566d514d2..57670c172b251075047b8128eaf88080e7db7df8 100644 (file)
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -32,9 +32,6 @@ struct ghcb *boot_ghcb;
 #undef __init
 #define __init
 
-#undef __head
-#define __head
-
 #define __BOOT_COMPRESSED
 
 u8 snp_vmpl;

diff --git a/arch/x86/boot/startup/gdt_idt.c b/arch/x86/boot/startup/gdt_idt.c
index a3112a69b06a77a1ca4cc5ece40a1218092012f5..d16102abdaec34823b9e3c1b640db09a191451dd 100644 (file)
--- a/arch/x86/boot/startup/gdt_idt.c
+++ b/arch/x86/boot/startup/gdt_idt.c
@@ -24,7 +24,7 @@
 static gate_desc bringup_idt_table[NUM_EXCEPTION_VECTORS] __page_aligned_data;
 
 /* This may run while still in the direct mapping */
-void __head startup_64_load_idt(void *vc_handler)
+void startup_64_load_idt(void *vc_handler)
 {
        struct desc_ptr desc = {
                .address = (unsigned long)rip_rel_ptr(bringup_idt_table),
@@ -46,7 +46,7 @@ void __head startup_64_load_idt(void *vc_handler)
 /*
  * Setup boot CPU state needed before kernel switches to virtual addresses.
  */
-void __head startup_64_setup_gdt_idt(void)
+void __init startup_64_setup_gdt_idt(void)
 {
        struct gdt_page *gp = rip_rel_ptr((void *)(__force unsigned long)&gdt_page);
        void *handler = NULL;

diff --git a/arch/x86/boot/startup/map_kernel.c b/arch/x86/boot/startup/map_kernel.c
index 332dbe6688c4d9e1565e5a434d07a8cbd559bfe6..83ba98d6157272760945021c9cfc3b99b3a04e4f 100644 (file)
--- a/arch/x86/boot/startup/map_kernel.c
+++ b/arch/x86/boot/startup/map_kernel.c
@@ -30,7 +30,7 @@ static inline bool check_la57_support(void)
        return true;
 }
 
-static unsigned long __head sme_postprocess_startup(struct boot_params *bp,
+static unsigned long __init sme_postprocess_startup(struct boot_params *bp,
                                                    pmdval_t *pmd,
                                                    unsigned long p2v_offset)
 {
@@ -84,7 +84,7 @@ static unsigned long __head sme_postprocess_startup(struct boot_params *bp,
  * the 1:1 mapping of memory. Kernel virtual addresses can be determined by
  * subtracting p2v_offset from the RIP-relative address.
  */
-unsigned long __head __startup_64(unsigned long p2v_offset,
+unsigned long __init __startup_64(unsigned long p2v_offset,
                                  struct boot_params *bp)
 {
        pmd_t (*early_pgts)[PTRS_PER_PMD] = rip_rel_ptr(early_dynamic_pgts);

diff --git a/arch/x86/boot/startup/sev-shared.c b/arch/x86/boot/startup/sev-shared.c
index e09c66845e43eae524ee4d6c1c861bfafede2358..08cc1568d8af27e8158363e5e478c5a25781706d 100644 (file)
--- a/arch/x86/boot/startup/sev-shared.c
+++ b/arch/x86/boot/startup/sev-shared.c
@@ -33,7 +33,7 @@ static u32 cpuid_ext_range_max __ro_after_init;
 
 bool sev_snp_needs_sfw;
 
-void __head __noreturn
+void __noreturn
 sev_es_terminate(unsigned int set, unsigned int reason)
 {
        u64 val = GHCB_MSR_TERM_REQ;
@@ -52,7 +52,7 @@ sev_es_terminate(unsigned int set, unsigned int reason)
 /*
  * The hypervisor features are available from GHCB version 2 onward.
  */
-u64 get_hv_features(void)
+u64 __init get_hv_features(void)
 {
        u64 val;
 
@@ -222,7 +222,7 @@ const struct snp_cpuid_table *snp_cpuid_get_table(void)
  *
  * Return: XSAVE area size on success, 0 otherwise.
  */
-static u32 __head snp_cpuid_calc_xsave_size(u64 xfeatures_en, bool compacted)
+static u32 snp_cpuid_calc_xsave_size(u64 xfeatures_en, bool compacted)
 {
        const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
        u64 xfeatures_found = 0;
@@ -258,7 +258,7 @@ static u32 __head snp_cpuid_calc_xsave_size(u64 xfeatures_en, bool compacted)
        return xsave_size;
 }
 
-static bool __head
+static bool
 snp_cpuid_get_validated_func(struct cpuid_leaf *leaf)
 {
        const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
@@ -300,7 +300,7 @@ static void snp_cpuid_hv_msr(void *ctx, struct cpuid_leaf *leaf)
                sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_CPUID_HV);
 }
 
-static int __head
+static int
 snp_cpuid_postprocess(void (*cpuid_fn)(void *ctx, struct cpuid_leaf *leaf),
                      void *ctx, struct cpuid_leaf *leaf)
 {
@@ -396,8 +396,8 @@ snp_cpuid_postprocess(void (*cpuid_fn)(void *ctx, struct cpuid_leaf *leaf),
  * Returns -EOPNOTSUPP if feature not enabled. Any other non-zero return value
  * should be treated as fatal by caller.
  */
-int __head snp_cpuid(void (*cpuid_fn)(void *ctx, struct cpuid_leaf *leaf),
-                    void *ctx, struct cpuid_leaf *leaf)
+int snp_cpuid(void (*cpuid_fn)(void *ctx, struct cpuid_leaf *leaf),
+             void *ctx, struct cpuid_leaf *leaf)
 {
        const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
 
@@ -439,7 +439,7 @@ int __head snp_cpuid(void (*cpuid_fn)(void *ctx, struct cpuid_leaf *leaf),
  * page yet, so it only supports the MSR based communication with the
  * hypervisor and only the CPUID exit-code.
  */
-void __head do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code)
+void do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code)
 {
        unsigned int subfn = lower_bits(regs->cx, 32);
        unsigned int fn = lower_bits(regs->ax, 32);
@@ -515,7 +515,7 @@ struct cc_setup_data {
  * Search for a Confidential Computing blob passed in as a setup_data entry
  * via the Linux Boot Protocol.
  */
-static __head
+static __init
 struct cc_blob_sev_info *find_cc_blob_setup_data(struct boot_params *bp)
 {
        struct cc_setup_data *sd = NULL;
@@ -543,7 +543,7 @@ struct cc_blob_sev_info *find_cc_blob_setup_data(struct boot_params *bp)
  * mapping needs to be updated in sync with all the changes to virtual memory
  * layout and related mapping facilities throughout the boot process.
  */
-static void __head setup_cpuid_table(const struct cc_blob_sev_info *cc_info)
+static void __init setup_cpuid_table(const struct cc_blob_sev_info *cc_info)
 {
        const struct snp_cpuid_table *cpuid_table_fw, *cpuid_table;
        int i;
@@ -571,7 +571,7 @@ static void __head setup_cpuid_table(const struct cc_blob_sev_info *cc_info)
        }
 }
 
-static int __head svsm_call_msr_protocol(struct svsm_call *call)
+static int svsm_call_msr_protocol(struct svsm_call *call)
 {
        int ret;
 
@@ -582,8 +582,8 @@ static int __head svsm_call_msr_protocol(struct svsm_call *call)
        return ret;
 }
 
-static void __head svsm_pval_4k_page(unsigned long paddr, bool validate,
-                                    struct svsm_ca *caa, u64 caa_pa)
+static void svsm_pval_4k_page(unsigned long paddr, bool validate,
+                             struct svsm_ca *caa, u64 caa_pa)
 {
        struct svsm_pvalidate_call *pc;
        struct svsm_call call = {};
@@ -624,8 +624,8 @@ static void __head svsm_pval_4k_page(unsigned long paddr, bool validate,
        native_local_irq_restore(flags);
 }
 
-static void __head pvalidate_4k_page(unsigned long vaddr, unsigned long paddr,
-                                    bool validate, struct svsm_ca *caa, u64 caa_pa)
+static void pvalidate_4k_page(unsigned long vaddr, unsigned long paddr,
+                             bool validate, struct svsm_ca *caa, u64 caa_pa)
 {
        int ret;
 
@@ -645,8 +645,8 @@ static void __head pvalidate_4k_page(unsigned long vaddr, unsigned long paddr,
                sev_evict_cache((void *)vaddr, 1);
 }
 
-static void __head __page_state_change(unsigned long vaddr, unsigned long paddr,
-                                      const struct psc_desc *desc)
+static void __page_state_change(unsigned long vaddr, unsigned long paddr,
+                               const struct psc_desc *desc)
 {
        u64 val, msr;
 
@@ -684,7 +684,7 @@ static void __head __page_state_change(unsigned long vaddr, unsigned long paddr,
  * Maintain the GPA of the SVSM Calling Area (CA) in order to utilize the SVSM
  * services needed when not running in VMPL0.
  */
-static bool __head svsm_setup_ca(const struct cc_blob_sev_info *cc_info,
+static bool __init svsm_setup_ca(const struct cc_blob_sev_info *cc_info,
                                 void *page)
 {
        struct snp_secrets_page *secrets_page;

diff --git a/arch/x86/boot/startup/sev-startup.c b/arch/x86/boot/startup/sev-startup.c
index 9f4b4ca7deaac99b975914cb49c7eef85e5feb91..39465a0ff4e5f3257f5ecb47efdfb205dbf3981d 100644 (file)
--- a/arch/x86/boot/startup/sev-startup.c
+++ b/arch/x86/boot/startup/sev-startup.c
@@ -44,7 +44,7 @@
 /* Include code shared with pre-decompression boot stage */
 #include "sev-shared.c"
 
-void __head
+void __init
 early_set_pages_state(unsigned long vaddr, unsigned long paddr,
                      unsigned long npages, const struct psc_desc *desc)
 {
@@ -63,7 +63,7 @@ early_set_pages_state(unsigned long vaddr, unsigned long paddr,
        }
 }
 
-void __head early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
+void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
                                         unsigned long npages)
 {
        struct psc_desc d = {
@@ -88,7 +88,7 @@ void __head early_snp_set_memory_private(unsigned long vaddr, unsigned long padd
        early_set_pages_state(vaddr, paddr, npages, &d);
 }
 
-void __head early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
+void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
                                        unsigned long npages)
 {
        struct psc_desc d = {
@@ -123,7 +123,7 @@ void __head early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr
  *
  * Scan for the blob in that order.
  */
-static __head struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp)
+static struct cc_blob_sev_info *__init find_cc_blob(struct boot_params *bp)
 {
        struct cc_blob_sev_info *cc_info;
 
@@ -149,7 +149,7 @@ found_cc_info:
        return cc_info;
 }
 
-static __head void svsm_setup(struct cc_blob_sev_info *cc_info)
+static void __init svsm_setup(struct cc_blob_sev_info *cc_info)
 {
        struct snp_secrets_page *secrets = (void *)cc_info->secrets_phys;
        struct svsm_call call = {};
@@ -190,7 +190,7 @@ static __head void svsm_setup(struct cc_blob_sev_info *cc_info)
        boot_svsm_caa_pa = pa;
 }
 
-bool __head snp_init(struct boot_params *bp)
+bool __init snp_init(struct boot_params *bp)
 {
        struct cc_blob_sev_info *cc_info;
 
@@ -219,7 +219,7 @@ bool __head snp_init(struct boot_params *bp)
        return true;
 }
 
-void __head __noreturn snp_abort(void)
+void __init __noreturn snp_abort(void)
 {
        sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
 }

diff --git a/arch/x86/boot/startup/sme.c b/arch/x86/boot/startup/sme.c
index 52b98e7624fe81dea429dc9af5d76fd54c2f3a2c..2ddde901c8c5b7083c84707968028ddff010bd1c 100644 (file)
--- a/arch/x86/boot/startup/sme.c
+++ b/arch/x86/boot/startup/sme.c
@@ -91,7 +91,7 @@ struct sme_populate_pgd_data {
  */
 static char sme_workarea[2 * PMD_SIZE] __section(".init.scratch");
 
-static void __head sme_clear_pgd(struct sme_populate_pgd_data *ppd)
+static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
 {
        unsigned long pgd_start, pgd_end, pgd_size;
        pgd_t *pgd_p;
@@ -106,7 +106,7 @@ static void __head sme_clear_pgd(struct sme_populate_pgd_data *ppd)
        memset(pgd_p, 0, pgd_size);
 }
 
-static pud_t __head *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
+static pud_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
 {
        pgd_t *pgd;
        p4d_t *p4d;
@@ -143,7 +143,7 @@ static pud_t __head *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
        return pud;
 }
 
-static void __head sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
+static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
 {
        pud_t *pud;
        pmd_t *pmd;
@@ -159,7 +159,7 @@ static void __head sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
        set_pmd(pmd, __pmd(ppd->paddr | ppd->pmd_flags));
 }
 
-static void __head sme_populate_pgd(struct sme_populate_pgd_data *ppd)
+static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
 {
        pud_t *pud;
        pmd_t *pmd;
@@ -185,7 +185,7 @@ static void __head sme_populate_pgd(struct sme_populate_pgd_data *ppd)
                set_pte(pte, __pte(ppd->paddr | ppd->pte_flags));
 }
 
-static void __head __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
+static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
 {
        while (ppd->vaddr < ppd->vaddr_end) {
                sme_populate_pgd_large(ppd);
@@ -195,7 +195,7 @@ static void __head __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
        }
 }
 
-static void __head __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
+static void __init __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
 {
        while (ppd->vaddr < ppd->vaddr_end) {
                sme_populate_pgd(ppd);
@@ -205,7 +205,7 @@ static void __head __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
        }
 }
 
-static void __head __sme_map_range(struct sme_populate_pgd_data *ppd,
+static void __init __sme_map_range(struct sme_populate_pgd_data *ppd,
                                   pmdval_t pmd_flags, pteval_t pte_flags)
 {
        unsigned long vaddr_end;
@@ -229,22 +229,22 @@ static void __head __sme_map_range(struct sme_populate_pgd_data *ppd,
        __sme_map_range_pte(ppd);
 }
 
-static void __head sme_map_range_encrypted(struct sme_populate_pgd_data *ppd)
+static void __init sme_map_range_encrypted(struct sme_populate_pgd_data *ppd)
 {
        __sme_map_range(ppd, PMD_FLAGS_ENC, PTE_FLAGS_ENC);
 }
 
-static void __head sme_map_range_decrypted(struct sme_populate_pgd_data *ppd)
+static void __init sme_map_range_decrypted(struct sme_populate_pgd_data *ppd)
 {
        __sme_map_range(ppd, PMD_FLAGS_DEC, PTE_FLAGS_DEC);
 }
 
-static void __head sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
+static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
 {
        __sme_map_range(ppd, PMD_FLAGS_DEC_WP, PTE_FLAGS_DEC_WP);
 }
 
-static unsigned long __head sme_pgtable_calc(unsigned long len)
+static unsigned long __init sme_pgtable_calc(unsigned long len)
 {
        unsigned long entries = 0, tables = 0;
 
@@ -281,7 +281,7 @@ static unsigned long __head sme_pgtable_calc(unsigned long len)
        return entries + tables;
 }
 
-void __head sme_encrypt_kernel(struct boot_params *bp)
+void __init sme_encrypt_kernel(struct boot_params *bp)
 {
        unsigned long workarea_start, workarea_end, workarea_len;
        unsigned long execute_start, execute_end, execute_len;
@@ -485,7 +485,7 @@ void __head sme_encrypt_kernel(struct boot_params *bp)
        native_write_cr3(__native_read_cr3());
 }
 
-void __head sme_enable(struct boot_params *bp)
+void __init sme_enable(struct boot_params *bp)
 {
        unsigned int eax, ebx, ecx, edx;
        unsigned long feature_mask;

diff --git a/arch/x86/include/asm/init.h b/arch/x86/include/asm/init.h
index 5a68e9db65189373f7c6d4d08718fcb3abc6c03b..01ccdd168df08024eeced804d031ea71fda27508 100644 (file)
--- a/arch/x86/include/asm/init.h
+++ b/arch/x86/include/asm/init.h
@@ -2,12 +2,6 @@
 #ifndef _ASM_X86_INIT_H
 #define _ASM_X86_INIT_H
 
-#if defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION < 170000
-#define __head __section(".head.text") __no_sanitize_undefined __no_stack_protector
-#else
-#define __head __section(".head.text") __no_sanitize_undefined __no_kstack_erase
-#endif
-
 struct x86_mapping_info {
        void *(*alloc_pgt_page)(void *); /* allocate buf for page table */
        void (*free_pgt_page)(void *, void *); /* free buf for page table */

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 76743dfad6ab9d2c49b8e71dcef0813bc63aa14b..80ef5d386b03dcc8e2dc184d72d6482b2b35c04f 100644 (file)
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -61,7 +61,7 @@ RESERVE_BRK(pagetables, INIT_MAP_SIZE)
  * any particular GDT layout, because we load our own as soon as we
  * can.
  */
-__HEAD
+       __INIT
 SYM_CODE_START(startup_32)
        movl pa(initial_stack),%ecx
        
@@ -136,6 +136,9 @@ SYM_CODE_END(startup_32)
  * If cpu hotplug is not supported then this code can go in init section
  * which will be freed later
  */
+#ifdef CONFIG_HOTPLUG_CPU
+       .text
+#endif
 SYM_FUNC_START(startup_32_smp)
        cld
        movl $(__BOOT_DS),%eax

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index d219963ecb605cdb918075ec3e5c425434fa25a6..21816b48537c3a345801579bd86d3f536314a2a7 100644 (file)
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -33,7 +33,7 @@
  * because we need identity-mapped pages.
  */
 
-       __HEAD
+       __INIT
        .code64
 SYM_CODE_START_NOALIGN(startup_64)
        UNWIND_HINT_END_OF_STACK

diff --git a/arch/x86/platform/pvh/head.S b/arch/x86/platform/pvh/head.S
index 1d78e5631bb81c7bd118b6aefd5d5f7de8c57b22..344030c1a81d46c9a3b22f185d631ebc32bc5206 100644 (file)
--- a/arch/x86/platform/pvh/head.S
+++ b/arch/x86/platform/pvh/head.S
@@ -24,7 +24,7 @@
 #include <asm/nospec-branch.h>
 #include <xen/interface/elfnote.h>
 
-       __HEAD
+       __INIT
 
 /*
  * Entry point for PVH guests.