[PATCH v4 09/12] elf: Introduce elf64_phdr_size() helper
COLD26d
From: Jinjie Ruan <hidden>
Date: 2026-09-07 12:53:44
Also in:
kexec, linux-fsdevel, linux-mm, lkml, loongarch
Subsystem:
exec & binfmt api, elf, filesystems (vfs and infrastructure), kdump, linux for powerpc (32-bit and 64-bit), proc filesystem, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Kees Cook, Alexander Viro, Christian Brauner, Andrew Morton, Baoquan He, Mike Rapoport, Pasha Tatashin, Pratyush Yadav, Madhavan Srinivasan, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Revision v4 of 3 in this series.
Revisions (3)
- v3 [diff vs current]
- v4 current
- v5 [diff vs current]
Add a common helper to compute the total size of an ELF64 header (Ehdr + program headers) from the number of program headers. Replace open-coded calculations in powerpc, x86, vmcore, and crash_core. On ppc64, struct elfhdr maps to elf64_hdr, so the powerpc change is a pure cleanup. No functional change intended. Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org> Cc: Thomas Gleixner <tglx@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Mike Rapoport <rppt@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Dave Young <ruirui.yang@linux.dev> Cc: Kees Cook <kees@kernel.org> Cc: Sourabh Jain <redacted> Signed-off-by: Jinjie Ruan <redacted> --- arch/powerpc/kexec/crash.c | 2 +- arch/powerpc/platforms/powernv/opal-core.c | 3 +-- arch/x86/kernel/crash.c | 3 +-- fs/proc/vmcore.c | 6 ++---- include/linux/elf.h | 4 ++++ kernel/crash_core.c | 2 +- 6 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
index 775895f31037..fc0105c7af4c 100644
--- a/arch/powerpc/kexec/crash.c
+++ b/arch/powerpc/kexec/crash.c@@ -478,7 +478,7 @@ unsigned int arch_crash_get_elfcorehdr_size(void) if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG)) phdr_cnt += CONFIG_CRASH_MAX_MEMORY_RANGES; - return sizeof(struct elfhdr) + (phdr_cnt * sizeof(Elf64_Phdr)); + return elf64_phdr_size(phdr_cnt); } /**
diff --git a/arch/powerpc/platforms/powernv/opal-core.c b/arch/powerpc/platforms/powernv/opal-core.c
index 32662d30d70f..fc0aad61504b 100644
--- a/arch/powerpc/platforms/powernv/opal-core.c
+++ b/arch/powerpc/platforms/powernv/opal-core.c@@ -309,8 +309,7 @@ static int __init create_opalcore(void) char *bufp; /* Get size of header & CPU notes for OPAL core */ - hdr_size = (sizeof(Elf64_Ehdr) + - ((oc_conf->ptload_cnt + 1) * sizeof(Elf64_Phdr))); + hdr_size = elf64_phdr_size(oc_conf->ptload_cnt + 1); cpu_notes_size = ((oc_conf->num_cpus * (CRASH_CORE_NOTE_HEAD_BYTES + CRASH_CORE_NOTE_NAME_BYTES + CRASH_CORE_NOTE_DESC_BYTES)) +
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index d6430a593778..e164749c5c1d 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c@@ -374,8 +374,7 @@ int crash_load_segments(struct kimage *image) pnum += 2 + CONFIG_NR_CPUS_DEFAULT; if (pnum < (unsigned long)PN_XNUM) { - kbuf.memsz = pnum * sizeof(Elf64_Phdr); - kbuf.memsz += sizeof(Elf64_Ehdr); + kbuf.memsz = elf64_phdr_size(pnum); image->elfcorehdr_index = image->nr_segments;
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 44d15436439f..ff324969d798 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c@@ -1238,8 +1238,7 @@ static int __init parse_crash_elf64_headers(void) } /* Read in all elf headers. */ - elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) + - ehdr.e_phnum * sizeof(Elf64_Phdr); + elfcorebuf_sz_orig = elf64_phdr_size(ehdr.e_phnum); elfcorebuf_sz = elfcorebuf_sz_orig; elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(elfcorebuf_sz_orig));
@@ -1605,8 +1604,7 @@ static int vmcore_add_device_ram_elf64(struct list_head *list, size_t count) } /* elfcorebuf_sz must always cover full pages. */ - new_size = sizeof(Elf64_Ehdr) + - (ehdr->e_phnum + count) * sizeof(Elf64_Phdr); + new_size = elf64_phdr_size(ehdr->e_phnum + count); new_size = roundup(new_size, PAGE_SIZE); /*
diff --git a/include/linux/elf.h b/include/linux/elf.h
index 5c402788da19..400f58a13d92 100644
--- a/include/linux/elf.h
+++ b/include/linux/elf.h@@ -109,4 +109,8 @@ static inline int arch_elf_adjust_prot(int prot, } #endif +static inline unsigned long elf64_phdr_size(unsigned long phdr_cnt) +{ + return phdr_cnt * sizeof(Elf64_Phdr) + sizeof(Elf64_Ehdr); +} #endif /* _LINUX_ELF_H */
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 39feb39b53be..b57a81f38ef4 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c@@ -193,7 +193,7 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map, */ nr_phdr++; - elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr); + elf_sz = elf64_phdr_size(nr_phdr); elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN); buf = vzalloc(elf_sz);
--
2.34.1