Commit 65c225d3 authored by Philipp Rudo's avatar Philipp Rudo Committed by Linus Torvalds

kernel/kexec_file.c: make purgatory_info->ehdr const

The kexec_purgatory buffer is read-only.  Thus all pointers into
kexec_purgatory are read-only, too.  Point this out by explicitly
marking purgatory_info->ehdr as 'const' and update the comments in
purgatory_info.

Link: http://lkml.kernel.org/r/20180321112751.22196-4-prudo@linux.vnet.ibm.comSigned-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 d2b8178c
...@@ -99,14 +99,19 @@ struct compat_kexec_segment { ...@@ -99,14 +99,19 @@ struct compat_kexec_segment {
#ifdef CONFIG_KEXEC_FILE #ifdef CONFIG_KEXEC_FILE
struct purgatory_info { struct purgatory_info {
/* Pointer to elf header of read only purgatory */ /*
Elf_Ehdr *ehdr; * Pointer to elf header at the beginning of kexec_purgatory.
* Note: kexec_purgatory is read only
/* Pointer to purgatory sechdrs which are modifiable */ */
const Elf_Ehdr *ehdr;
/*
* Temporary, modifiable buffer for sechdrs used for relocation.
* This memory can be freed post image load.
*/
Elf_Shdr *sechdrs; Elf_Shdr *sechdrs;
/* /*
* Temporary buffer location where purgatory is loaded and relocated * Temporary, modifiable buffer for stripped purgatory used for
* This memory can be freed post image load * relocation. This memory can be freed post image load.
*/ */
void *purgatory_buf; void *purgatory_buf;
......
...@@ -941,7 +941,7 @@ int kexec_load_purgatory(struct kimage *image, unsigned long min, ...@@ -941,7 +941,7 @@ int kexec_load_purgatory(struct kimage *image, unsigned long min,
if (kexec_purgatory_size <= 0) if (kexec_purgatory_size <= 0)
return -EINVAL; return -EINVAL;
pi->ehdr = (Elf_Ehdr *)kexec_purgatory; pi->ehdr = (const Elf_Ehdr *)kexec_purgatory;
ret = __kexec_load_purgatory(image, min, max, top_down); ret = __kexec_load_purgatory(image, min, max, top_down);
if (ret) if (ret)
...@@ -965,9 +965,9 @@ int kexec_load_purgatory(struct kimage *image, unsigned long min, ...@@ -965,9 +965,9 @@ int kexec_load_purgatory(struct kimage *image, unsigned long min,
static Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi, static Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi,
const char *name) const char *name)
{ {
const Elf_Ehdr *ehdr;
Elf_Sym *syms; Elf_Sym *syms;
Elf_Shdr *sechdrs; Elf_Shdr *sechdrs;
Elf_Ehdr *ehdr;
int i, k; int i, k;
const char *strtab; const char *strtab;
......
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