From: Naveen N. Rao naveen.n.rao@linux.vnet.ibm.com
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/include/asm/kexec.h | 7 +++++++ include/linux/kexec.h | 26 ++++++++++++++++++++++---- kernel/kexec_file.c | 18 ------------------ 3 files changed, 29 insertions(+), 22 deletions(-)
--- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -20,6 +20,7 @@ #ifndef __ASSEMBLY__
#include <linux/string.h> +#include <linux/module.h>
#include <asm/page.h> #include <asm/ptrace.h> @@ -206,6 +207,12 @@ struct kexec_entry64_regs { uint64_t r15; uint64_t rip; }; + +#ifdef CONFIG_KEXEC_FILE +int arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, + Elf_Shdr *sechdrs, unsigned int relsec); +#define arch_kexec_apply_relocations_add arch_kexec_apply_relocations_add +#endif #endif
typedef void crash_vmclear_fn(void); --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -148,6 +148,28 @@ struct kexec_file_ops { kexec_verify_sig_t *verify_sig; #endif }; + +#ifndef arch_kexec_apply_relocations_add +/* Apply relocations of type RELA */ +static inline int +arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, + Elf_Shdr *sechdrs, unsigned int relsec) +{ + pr_err("RELA relocation unsupported.\n"); + return -ENOEXEC; +} +#endif + +#ifndef arch_kexec_apply_relocations +/* Apply relocations of type REL */ +static inline int +arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, + unsigned int relsec) +{ + pr_err("REL relocation unsupported.\n"); + return -ENOEXEC; +} +#endif #endif
struct kimage { @@ -320,10 +342,6 @@ void * __weak arch_kexec_kernel_image_lo int __weak arch_kimage_file_post_load_cleanup(struct kimage *image); int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, unsigned long buf_len); -int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, - Elf_Shdr *sechdrs, unsigned int relsec); -int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, - unsigned int relsec); void arch_kexec_protect_crashkres(void); void arch_kexec_unprotect_crashkres(void);
--- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -59,24 +59,6 @@ int __weak arch_kexec_kernel_verify_sig( } #endif
-/* Apply relocations of type RELA */ -int __weak -arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, - unsigned int relsec) -{ - pr_err("RELA relocation unsupported.\n"); - return -ENOEXEC; -} - -/* Apply relocations of type REL */ -int __weak -arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, - unsigned int relsec) -{ - 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