diff options
| author | Dave Martin <Dave.Martin@arm.com> | 2017-10-31 15:50:53 +0000 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2017-11-03 15:24:11 +0000 |
| commit | 27e64b4be4b863d884f3ec1686a2f744ae93a1b9 (patch) | |
| tree | ae548b3f473891f3aec3b0cbc53d44173fb101e7 /fs | |
| parent | c7f5828bf77dcbd61d51f4736c1d5aa35663fbb4 (diff) | |
| download | linux-27e64b4be4b863d884f3ec1686a2f744ae93a1b9.tar.gz | |
regset: Add support for dynamically sized regsets
Currently the regset API doesn't allow for the possibility that
regsets (or at least, the amount of meaningful data in a regset)
may change in size.
In particular, this results in useless padding being added to
coredumps if a regset's current size is smaller than its
theoretical maximum size.
This patch adds a get_size() function to struct user_regset.
Individual regset implementations can implement this function to
return the current size of the regset data. A regset_size()
function is added to provide callers with an abstract interface for
determining the size of a regset without needing to know whether
the regset is dynamically sized or not.
The only affected user of this interface is the ELF coredump code:
This patch ports ELF coredump to dump regsets with their actual
size in the coredump. This has no effect except for new regsets
that are dynamically sized and provide a get_size() implementation.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: H. J. Lu <hjl.tools@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/binfmt_elf.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 73b01e474fdc..c697882b3aba 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1699,7 +1699,7 @@ static int fill_thread_core_info(struct elf_thread_core_info *t, long signr, size_t *total) { unsigned int i; - unsigned int regset_size = view->regsets[0].n * view->regsets[0].size; + unsigned int regset0_size = regset_size(t->task, &view->regsets[0]); /* * NT_PRSTATUS is the one special case, because the regset data @@ -1708,11 +1708,11 @@ static int fill_thread_core_info(struct elf_thread_core_info *t, * We assume that regset 0 is NT_PRSTATUS. */ fill_prstatus(&t->prstatus, t->task, signr); - (void) view->regsets[0].get(t->task, &view->regsets[0], 0, regset_size, + (void) view->regsets[0].get(t->task, &view->regsets[0], 0, regset0_size, &t->prstatus.pr_reg, NULL); fill_note(&t->notes[0], "CORE", NT_PRSTATUS, - PRSTATUS_SIZE(t->prstatus, regset_size), &t->prstatus); + PRSTATUS_SIZE(t->prstatus, regset0_size), &t->prstatus); *total += notesize(&t->notes[0]); do_thread_regset_writeback(t->task, &view->regsets[0]); @@ -1728,7 +1728,7 @@ static int fill_thread_core_info(struct elf_thread_core_info *t, if (regset->core_note_type && regset->get && (!regset->active || regset->active(t->task, regset))) { int ret; - size_t size = regset->n * regset->size; + size_t size = regset_size(t->task, regset); void *data = kmalloc(size, GFP_KERNEL); if (unlikely(!data)) return 0; @@ -1743,7 +1743,7 @@ static int fill_thread_core_info(struct elf_thread_core_info *t, size, data); else { SET_PR_FPVALID(&t->prstatus, - 1, regset_size); + 1, regset0_size); fill_note(&t->notes[i], "CORE", NT_PRFPREG, size, data); } |