commit 3e35142ef99fe6b4fe5d834ad43ee13cca10a2dc upstream.

Since commit d1bcae833b32f1 ("ELF: Don't generate unused section symbols") [1], binutils (v2.36+) started dropping section symbols that it thought were unused. This isn't an issue in general, but with kexec_file.c, gcc is placing kexec_arch_apply_relocations[_add] into a separate .text.unlikely section and the section symbol ".text.unlikely" is being dropped. Due to this, recordmcount is unable to find a non-weak symbol in .text.unlikely to generate a relocation record against.

Address this by dropping the weak attribute from these functions. Instead, follow the existing pattern of having architectures #define the name of the function they want to override in their headers.

[1] https://sourceware.org/git/?p=binutils-gdb.git%3Ba=commit%3Bh=d1bcae833b32f1

[akpm@linux-foundation.org: arch/s390/include/asm/kexec.h needs linux/module.h] Link: https://lkml.kernel.org/r/20220519091237.676736-1-naveen.n.rao@linux.vnet.ib... Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Naveen N. Rao naveen.n.rao@linux.vnet.ibm.com Cc: "Eric W. Biederman" ebiederm@xmission.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org --- arch/s390/include/asm/kexec.h | 10 ++++++++ arch/x86/include/asm/kexec.h | 9 +++++++ include/linux/kexec.h | 46 +++++++++++++++++++++++++++++------ kernel/kexec_file.c | 34 -------------------------- 4 files changed, 57 insertions(+), 42 deletions(-)

diff --git a/arch/s390/include/asm/kexec.h b/arch/s390/include/asm/kexec.h index 7f3c9ac34bd8d1..63098df81c9f2a 100644 --- a/arch/s390/include/asm/kexec.h +++ b/arch/s390/include/asm/kexec.h @@ -9,6 +9,8 @@ #ifndef _S390_KEXEC_H #define _S390_KEXEC_H

+#include <linux/module.h> + #include <asm/processor.h> #include <asm/page.h> #include <asm/setup.h> @@ -83,4 +85,12 @@ struct kimage_arch { extern const struct kexec_file_ops s390_kexec_image_ops; extern const struct kexec_file_ops s390_kexec_elf_ops;

+#ifdef CONFIG_KEXEC_FILE +struct purgatory_info; +int arch_kexec_apply_relocations_add(struct purgatory_info *pi, + Elf_Shdr *section, + const Elf_Shdr *relsec, + const Elf_Shdr *symtab); +#define arch_kexec_apply_relocations_add arch_kexec_apply_relocations_add +#endif #endif /*_S390_KEXEC_H */ diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h index 5e7d6b46de97d6..367da081f7d9d9 100644 --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -22,6 +22,7 @@

#include <linux/string.h> #include <linux/kernel.h> +#include <linux/module.h>

#include <asm/page.h> #include <asm/ptrace.h> @@ -201,6 +202,14 @@ extern int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, extern void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages); #define arch_kexec_pre_free_pages arch_kexec_pre_free_pages

+#ifdef CONFIG_KEXEC_FILE +struct purgatory_info; +int arch_kexec_apply_relocations_add(struct purgatory_info *pi, + Elf_Shdr *section, + const Elf_Shdr *relsec, + const Elf_Shdr *symtab); +#define arch_kexec_apply_relocations_add arch_kexec_apply_relocations_add +#endif #endif

typedef void crash_vmclear_fn(void); diff --git a/include/linux/kexec.h b/include/linux/kexec.h index a1cffce3de8cd7..64f23bab6255da 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -186,14 +186,6 @@ void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name); int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf, unsigned long buf_len); void * __weak arch_kexec_kernel_image_load(struct kimage *image); -int __weak arch_kexec_apply_relocations_add(struct purgatory_info *pi, - Elf_Shdr *section, - const Elf_Shdr *relsec, - const Elf_Shdr *symtab); -int __weak arch_kexec_apply_relocations(struct purgatory_info *pi, - Elf_Shdr *section, - const Elf_Shdr *relsec, - const Elf_Shdr *symtab);

extern int kexec_add_buffer(struct kexec_buf *kbuf); int kexec_locate_mem_hole(struct kexec_buf *kbuf); @@ -216,6 +208,44 @@ extern int crash_exclude_mem_range(struct crash_mem *mem, unsigned long long mend); extern int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map, void **addr, unsigned long *sz); + +#ifndef arch_kexec_apply_relocations_add +/* + * arch_kexec_apply_relocations_add - apply relocations of type RELA + * @pi: Purgatory to be relocated. + * @section: Section relocations applying to. + * @relsec: Section containing RELAs. + * @symtab: Corresponding symtab. + * + * Return: 0 on success, negative errno on error. + */ +static inline int +arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section, + const Elf_Shdr *relsec, const Elf_Shdr *symtab) +{ + pr_err("RELA relocation unsupported.\n"); + return -ENOEXEC; +} +#endif + +#ifndef arch_kexec_apply_relocations +/* + * arch_kexec_apply_relocations - apply relocations of type REL + * @pi: Purgatory to be relocated. + * @section: Section relocations applying to. + * @relsec: Section containing RELs. + * @symtab: Corresponding symtab. + * + * Return: 0 on success, negative errno on error. + */ +static inline int +arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section, + const Elf_Shdr *relsec, const Elf_Shdr *symtab) +{ + pr_err("REL relocation unsupported.\n"); + return -ENOEXEC; +} +#endif #endif /* CONFIG_KEXEC_FILE */

#ifdef CONFIG_KEXEC_ELF diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index b17998fa03f125..5b58149bcd900b 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -107,40 +107,6 @@ int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, } #endif

-/* - * arch_kexec_apply_relocations_add - apply relocations of type RELA - * @pi: Purgatory to be relocated. - * @section: Section relocations applying to. - * @relsec: Section containing RELAs. - * @symtab: Corresponding symtab. - * - * Return: 0 on success, negative errno on error. - */ -int __weak -arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section, - const Elf_Shdr *relsec, const Elf_Shdr *symtab) -{ - pr_err("RELA relocation unsupported.\n"); - return -ENOEXEC; -} - -/* - * arch_kexec_apply_relocations - apply relocations of type REL - * @pi: Purgatory to be relocated. - * @section: Section relocations applying to. - * @relsec: Section containing RELs. - * @symtab: Corresponding symtab. - * - * Return: 0 on success, negative errno on error. - */ -int __weak -arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section, - const Elf_Shdr *relsec, const Elf_Shdr *symtab) -{ - pr_err("REL relocation unsupported.\n"); - return -ENOEXEC; -} - /* * Free up memory used by kernel, initrd, and command line. This is temporary * memory allocation which is not needed any more after these buffers have

base-commit: 23db944f754e99abf814a79a2273b0191d35e4ff