BINFMT: fill_elf_header cleanup - use straight memset first (6970c8ef) · Commits · 戴 / test

This patch does simplify fill_elf_header function by setting to zero the whole elf header first. So we fillup the fields we really need only. before: text data bss dec hex filename 11735 80 0 11815 2e27 fs/binfmt_elf.o after: text data bss dec hex filename 11710 80 0 11790 2e0e fs/binfmt_elf.o viola, 25 bytes of text is freed Signed-off-by:

Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

fs/binfmt_elf.c

+3 −6

Original line number	Diff line number	Diff line
		@@ -1255,26 +1255,23 @@ static int writenote(struct memelfnote men, struct file file,
		static void fill_elf_header(struct elfhdr *elf, int segs,
		u16 machine, u32 flags, u8 osabi)
		{
		memset(elf, 0, sizeof(*elf));

		memcpy(elf->e_ident, ELFMAG, SELFMAG);
		elf->e_ident[EI_CLASS] = ELF_CLASS;
		elf->e_ident[EI_DATA] = ELF_DATA;
		elf->e_ident[EI_VERSION] = EV_CURRENT;
		elf->e_ident[EI_OSABI] = ELF_OSABI;
		memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);

		elf->e_type = ET_CORE;
		elf->e_machine = machine;
		elf->e_version = EV_CURRENT;
		elf->e_entry = 0;
		elf->e_phoff = sizeof(struct elfhdr);
		elf->e_shoff = 0;
		elf->e_flags = flags;
		elf->e_ehsize = sizeof(struct elfhdr);
		elf->e_phentsize = sizeof(struct elf_phdr);
		elf->e_phnum = segs;
		elf->e_shentsize = 0;
		elf->e_shnum = 0;
		elf->e_shstrndx = 0;

		return;
		}

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