4.9-stable review patch. If anyone has any objections, please let me know.
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From: "Maciej W. Rozycki" macro@mips.com
[ Upstream commit 2f819db565e82e5f73cd42b39925098986693378 ]
The regset API documented in <linux/regset.h> defines -ENODEV as the result of the `->active' handler to be used where the feature requested is not available on the hardware found. However code handling core file note generation in `fill_thread_core_info' interpretes any non-zero result from the `->active' handler as the regset requested being active. Consequently processing continues (and hopefully gracefully fails later on) rather than being abandoned right away for the regset requested.
Fix the problem then by making the code proceed only if a positive result is returned from the `->active' handler.
Signed-off-by: Maciej W. Rozycki macro@mips.com Signed-off-by: Paul Burton paul.burton@mips.com Fixes: 4206d3aa1978 ("elf core dump: notes user_regset") Patchwork: https://patchwork.linux-mips.org/patch/19332/ Cc: Alexander Viro viro@zeniv.linux.org.uk Cc: James Hogan jhogan@kernel.org Cc: Ralf Baechle ralf@linux-mips.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/binfmt_elf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1706,7 +1706,7 @@ static int fill_thread_core_info(struct 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);