When CONFIG_RANDSTRUCT enabled, members of task_struct are randomized. There is a chance that TASK_STACK_CANARY be out of 12bit immediate's range and causes build errors. TASK_STACK_CANARY is naturally aligned, so fix it by replacing ld.d/st.d with ldptr.d/stptr.d which have 14bit immediates.
Cc: stable@vger.kernel.org Reported-by: kernel test robot lkp@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202511240656.0NaPcJs1-lkp@intel.com/ Suggested-by: Rui Wang wangrui@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- arch/loongarch/kernel/switch.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/loongarch/kernel/switch.S b/arch/loongarch/kernel/switch.S index 9c23cb7e432f..3007e909e0d8 100644 --- a/arch/loongarch/kernel/switch.S +++ b/arch/loongarch/kernel/switch.S @@ -25,8 +25,8 @@ SYM_FUNC_START(__switch_to) stptr.d a4, a0, THREAD_SCHED_CFA #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP) la t7, __stack_chk_guard - LONG_L t8, a1, TASK_STACK_CANARY - LONG_S t8, t7, 0 + ldptr.d t8, a1, TASK_STACK_CANARY + stptr.d t8, t7, 0 #endif move tp, a2 cpu_restore_nonscratch a1
On Tue, 25 Nov 2025, at 4:25 PM, Huacai Chen wrote:
When CONFIG_RANDSTRUCT enabled, members of task_struct are randomized. There is a chance that TASK_STACK_CANARY be out of 12bit immediate's range and causes build errors. TASK_STACK_CANARY is naturally aligned, so fix it by replacing ld.d/st.d with ldptr.d/stptr.d which have 14bit immediates.
Hi Huacai,
What about 32bit build in this case?
Thanks Jiaxun
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