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| author | Philipp Rudo <prudo@linux.vnet.ibm.com> | 2018-04-13 15:36:17 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-13 17:10:28 -0700 |
| commit | 65c225d3280542f3ea145e052215ce0538f6bb69 (patch) | |
| tree | 7d8d0f4239303c4182cf79c35ed2012aca64832c | |
| parent | d2b8178ca7324a21495cb71049b4e4a041ab5942 (diff) | |
| download | linux-stable-65c225d3280542f3ea145e052215ce0538f6bb69.tar.gz linux-stable-65c225d3280542f3ea145e052215ce0538f6bb69.tar.bz2 linux-stable-65c225d3280542f3ea145e052215ce0538f6bb69.zip | |
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.com
Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com>
Acked-by: Dave 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/kexec.h | 17 | ||||
| -rw-r--r-- | kernel/kexec_file.c | 4 |
2 files changed, 13 insertions, 8 deletions
diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 08b8b9d00f97..8c5819d1a808 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -99,14 +99,19 @@ struct compat_kexec_segment { #ifdef CONFIG_KEXEC_FILE struct purgatory_info { - /* Pointer to elf header of read only purgatory */ - Elf_Ehdr *ehdr; - - /* Pointer to purgatory sechdrs which are modifiable */ + /* + * Pointer to elf header at the beginning of kexec_purgatory. + * Note: kexec_purgatory is read only + */ + const Elf_Ehdr *ehdr; + /* + * Temporary, modifiable buffer for sechdrs used for relocation. + * This memory can be freed post image load. + */ Elf_Shdr *sechdrs; /* - * Temporary buffer location where purgatory is loaded and relocated - * This memory can be freed post image load + * Temporary, modifiable buffer for stripped purgatory used for + * relocation. This memory can be freed post image load. */ void *purgatory_buf; diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 81ba4f782486..12cf9c9ff0bc 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -941,7 +941,7 @@ int kexec_load_purgatory(struct kimage *image, unsigned long min, if (kexec_purgatory_size <= 0) return -EINVAL; - pi->ehdr = (Elf_Ehdr *)kexec_purgatory; + pi->ehdr = (const Elf_Ehdr *)kexec_purgatory; ret = __kexec_load_purgatory(image, min, max, top_down); if (ret) @@ -965,9 +965,9 @@ out: static Elf_Sym *kexec_purgatory_find_symbol(struct purgatory_info *pi, const char *name) { + const Elf_Ehdr *ehdr; Elf_Sym *syms; Elf_Shdr *sechdrs; - Elf_Ehdr *ehdr; int i, k; const char *strtab; |