This is a note to let you know that I've just added the patch titled kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add] to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kexec_file-drop-weak-attribute-from-arch_kexec_apply_relocations.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 3e35142ef99fe6b4fe5d834ad43ee13cca10a2dc Mon Sep 17 00:00:00 2001 From: "Naveen N. Rao" <naveen.n.rao@xxxxxxxxxxxxxxxxxx> Date: Thu, 19 May 2022 14:42:37 +0530 Subject: kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add] From: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx> 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;a=commit;h=d1bcae833b32f1 [akpm@xxxxxxxxxxxxxxxxxxxx: arch/s390/include/asm/kexec.h needs linux/module.h] Link: https://lkml.kernel.org/r/20220519091237.676736-1-naveen.n.rao@xxxxxxxxxxxxxxxxxx Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/include/asm/kexec.h | 6 ++++++ include/linux/kexec.h | 26 ++++++++++++++++++++++---- kernel/kexec_file.c | 18 ------------------ 3 files changed, 28 insertions(+), 22 deletions(-) --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -21,6 +21,7 @@ #ifndef __ASSEMBLY__ #include <linux/string.h> +#include <linux/module.h> #include <asm/page.h> #include <asm/ptrace.h> @@ -217,6 +218,11 @@ extern int arch_kexec_post_alloc_pages(v 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 +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 @@ -163,6 +163,28 @@ int __weak arch_kexec_walk_mem(struct ke int (*func)(u64, u64, void *)); extern int kexec_add_buffer(struct kexec_buf *kbuf); int kexec_locate_mem_hole(struct kexec_buf *kbuf); + +#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 /* CONFIG_KEXEC_FILE */ struct kimage { @@ -288,10 +310,6 @@ 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 @@ -53,24 +53,6 @@ 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 Patches currently in stable-queue which might be from naveen.n.rao@xxxxxxxxxxxxxxxxxx are queue-4.14/kexec_file-drop-weak-attribute-from-arch_kexec_apply_relocations.patch queue-4.14/powerpc-enable-execve-syscall-exit-tracepoint.patch