Regset active hooks provide a way to query how many registers in the register set are active at any point of time. Currently this information is being ignored while creating core dump sections corresponding to any core note register set. This way the core dump will contain data which are not part of the active context of the process and may not be useful. This patch will make sure that only the active part of the register set are captured during the core dump process which will reduce the core dump size.
Signed-off-by: Anshuman Khandual <khand...@linux.vnet.ibm.com> --- NOTE: Pedro Alves has mentioned that producing smaller note sections in the core dump may break some existing consumers. I request suggestions, reviews and test reports on different architectures to prove that this patch does not break any existing consumer. Thank you. Please find the previous discussion here https://lkml.org/lkml/2014/5/20/185 Regards Anshuman fs/binfmt_elf.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index aa3cb62..00aba07 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1551,10 +1551,18 @@ static int fill_thread_core_info(struct elf_thread_core_info *t, const struct user_regset *regset = &view->regsets[i]; do_thread_regset_writeback(t->task, regset); if (regset->core_note_type && regset->get && - (!regset->active || regset->active(t->task, regset))) { + (!regset->active || regset->active(t->task, regset) > 0)) { int ret; - size_t size = regset->n * regset->size; - void *data = kmalloc(size, GFP_KERNEL); + size_t size; + void *data; + + if (!regset->active) + size = regset->n * regset->size; + else + size = regset->active(t->task, regset) + * regset->size; + + data = kmalloc(size, GFP_KERNEL); if (unlikely(!data)) return 0; ret = regset->get(t->task, regset, -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
