Commit 620f697c authored by Philipp Rudo's avatar Philipp Rudo Committed by Linus Torvalds
Browse files

kernel/kexec_file.c: remove unneeded variables in kexec_purgatory_setup_sechdrs 

The main loop currently uses quite a lot of variables to update the
section headers.  Some of them are unnecessary.  So clean them up a
little.

Link: http://lkml.kernel.org/r/20180321112751.22196-9-prudo@linux.vnet.ibm.com


Signed-off-by: default avatarPhilipp Rudo <prudo@linux.vnet.ibm.com>
Acked-by: default avatarDave Young <dyoung@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f1b1cca3

kernel/kexec_file.c

+12 −22
Original line number Diff line number Diff line
@@ -785,12 +785,8 @@ out: 
static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,

					 struct kexec_buf *kbuf)

{

	unsigned long curr_load_addr;

	unsigned long load_addr;

	unsigned long bss_addr;

	unsigned long offset;

	unsigned char *buf_addr;

	unsigned char *src;

	Elf_Shdr *sechdrs;

	int i;
@@ -823,20 +819,18 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi, 
						sechdrs[i].sh_offset;

	}



	/* Load SHF_ALLOC sections */

	buf_addr = kbuf->buffer;

	load_addr = curr_load_addr = kbuf->mem;

	bss_addr = load_addr + kbuf->bufsz;

	offset = 0;

	bss_addr = kbuf->mem + kbuf->bufsz;

	kbuf->image->start = pi->ehdr->e_entry;



	for (i = 0; i < pi->ehdr->e_shnum; i++) {

		unsigned long align;

		void *src, *dst;



		if (!(sechdrs[i].sh_flags & SHF_ALLOC))

			continue;



		align = sechdrs[i].sh_addralign;



		if (sechdrs[i].sh_type == SHT_NOBITS) {

			bss_addr = ALIGN(bss_addr, align);

			sechdrs[i].sh_addr = bss_addr;
@@ -844,31 +838,27 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi, 
			continue;

		}



		curr_load_addr = ALIGN(curr_load_addr, align);

		offset = curr_load_addr - load_addr;

		/* We already modifed ->sh_offset to keep src addr */

		src = (char *)sechdrs[i].sh_offset;

		memcpy(buf_addr + offset, src, sechdrs[i].sh_size);



		offset = ALIGN(offset, align);

		if (sechdrs[i].sh_flags & SHF_EXECINSTR &&

		    pi->ehdr->e_entry >= sechdrs[i].sh_addr &&

		    pi->ehdr->e_entry < (sechdrs[i].sh_addr

					 + sechdrs[i].sh_size)) {

			kbuf->image->start -= sechdrs[i].sh_addr;

			kbuf->image->start += curr_load_addr;

			kbuf->image->start += kbuf->mem + offset;

		}



		/* Store load address and source address of section */

		sechdrs[i].sh_addr = curr_load_addr;

		src = (void *)sechdrs[i].sh_offset;

		dst = pi->purgatory_buf + offset;

		memcpy(dst, src, sechdrs[i].sh_size);



		sechdrs[i].sh_addr = kbuf->mem + offset;



		/*

		 * This section got copied to temporary buffer. Update

		 * ->sh_offset accordingly.

		 */

		sechdrs[i].sh_offset = (unsigned long)(buf_addr + offset);



		/* Advance to the next address */

		curr_load_addr += sechdrs[i].sh_size;

		sechdrs[i].sh_offset = (unsigned long)dst;

		offset += sechdrs[i].sh_size;

	}



	return 0;

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