Hi Al Viro,
On Mon, 15 Feb 2021 at 01:25, Al Viro viro@zeniv.linux.org.uk wrote:
On Mon, Jan 25, 2021 at 10:01:48PM +0530, Naresh Kamboju wrote:
commit 8a3cc755b13808eba74846dfd1033fcbc21f9a65 Author: Al Viro viro@zeniv.linux.org.uk Date: Sun Mar 8 09:16:37 2020 -0400
coredump: don't bother with do_truncate() have dump_skip() just remember how much needs to be skipped, leave actual seeks/writing zeroes to the next dump_emit() or the end of coredump output, whichever comes first. And instead of playing with do_truncate() in the end, just write one NUL at the end of the last gap (if any). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>fs/binfmt_elf.c | 1 - fs/coredump.c | 56 +++++++++++++++++++++++++++--------------------- include/linux/binfmts.h | 1 + include/linux/coredump.h | 1 -
Test case output link, https://lkft.validation.linaro.org/scheduler/job/2184975#L1369 https://lkft.validation.linaro.org/scheduler/job/2184972#L1358
I think I see what's going on. Could you check if the following fixes your reproducer?
diff --git a/arch/powerpc/platforms/cell/spufs/coredump.c b/arch/powerpc/platforms/cell/spufs/coredump.c index 60b5583e9eaf..1a587618015c 100644 --- a/arch/powerpc/platforms/cell/spufs/coredump.c +++ b/arch/powerpc/platforms/cell/spufs/coredump.c @@ -149,8 +149,7 @@ static int spufs_arch_write_note(struct spu_context *ctx, int i, return -EIO; }
if (!dump_skip(cprm, roundup(cprm->pos - ret + sz, 4) - cprm->pos))return -EIO;
dump_skip_to(cprm, roundup(cprm->pos - ret + sz, 4)); return 0;}
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 66137d5dca5f..474a3c7dd5ce 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -2267,8 +2267,7 @@ static int elf_core_dump(struct coredump_params *cprm) goto end_coredump;
/* Align to page */
if (!dump_skip(cprm, dataoff - cprm->pos))goto end_coredump;
dump_skip_to(cprm, dataoff); for (i = 0; i < vma_count; i++) { struct core_vma_metadata *meta = vma_meta + i;diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index be4062b8ba75..01f043971644 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -1640,8 +1640,7 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm) goto end_coredump; }
if (!dump_skip(cprm, dataoff - cprm->pos))goto end_coredump;
dump_skip_to(cprm, dataoff); if (!elf_fdpic_dump_segments(cprm, vma_meta, vma_count)) goto end_coredump;diff --git a/fs/coredump.c b/fs/coredump.c index 27a93f724251..bfac7422cd14 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -894,7 +894,14 @@ int dump_emit(struct coredump_params *cprm, const void *addr, int nr) } EXPORT_SYMBOL(dump_emit);
-int dump_skip(struct coredump_params *cprm, size_t nr) +void dump_skip_to(struct coredump_params *cprm, unsigned long pos) +{
cprm->to_skip = pos - cprm->pos;return 0;
fs/coredump.c:903:9: error: 'return' with a value, in function returning void [-Werror=return-type] 903 | return 0; | ^
Build failed due to above error.
build log link, https://gitlab.com/Linaro/lkft/users/naresh.kamboju/linux/-/jobs/1029838856#...
- Naresh