6.12-stable review patch. If anyone has any objections, please let me know.
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From: Yongxin Liu yongxin.liu@windriver.com
[ Upstream commit c8161e5304abb26e6c0bec6efc947992500fa6c5 ]
Zero can be a valid value of num_records. For example, on Intel Atom x6425RE, only x87 and SSE are supported (features 0, 1), and fpu_user_cfg.max_features is 3. The for_each_extended_xfeature() loop only iterates feature 2, which is not enabled, so num_records = 0. This is valid and should not cause core dump failure.
The issue is that dump_xsave_layout_desc() returns 0 for both genuine errors (dump_emit() failure) and valid cases (no extended features). Use negative return values for errors and only abort on genuine failures.
Fixes: ba386777a30b ("x86/elf: Add a new FPU buffer layout info to x86 core files") Signed-off-by: Yongxin Liu yongxin.liu@windriver.com Signed-off-by: Ingo Molnar mingo@kernel.org Link: https://patch.msgid.link/20251210000219.4094353-2-yongxin.liu@windriver.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kernel/fpu/xstate.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 22abb5ee0cf2..aacb59c4a35c 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1879,7 +1879,7 @@ static int dump_xsave_layout_desc(struct coredump_params *cprm) };
if (!dump_emit(cprm, &xc, sizeof(xc))) - return 0; + return -1;
num_records++; } @@ -1917,7 +1917,7 @@ int elf_coredump_extra_notes_write(struct coredump_params *cprm) return 1;
num_records = dump_xsave_layout_desc(cprm); - if (!num_records) + if (num_records < 0) return 1;
/* Total size should be equal to the number of records */