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| author | Tejun Heo <tj@kernel.org> | 2026-10-07 08:01:02 -1000 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2026-10-07 08:01:02 -1000 |
| commit | 92b542db38bf7cb4de583b2ca37febc549db0ce4 (patch) | |
| tree | 30dcfdb338f7fdba597e1ec9314c2006df86f525 /include/linux/randomize_kstack.h | |
| parent | fee1265a725725dac0ff7459f912d69558798b36 (diff) | |
| parent | d1a4549a3645e55cc9ade09e360280590b3c9559 (diff) | |
| download | linux-next-92b542db38bf7cb4de583b2ca37febc549db0ce4.tar.gz linux-next-92b542db38bf7cb4de583b2ca37febc549db0ce4.zip | |
Merge branch 'for-7.3-fixes' into for-next
Diffstat (limited to 'include/linux/randomize_kstack.h')
| -rw-r--r-- | include/linux/randomize_kstack.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/randomize_kstack.h b/include/linux/randomize_kstack.h index 024fc20e7762..d8b939f50bba 100644 --- a/include/linux/randomize_kstack.h +++ b/include/linux/randomize_kstack.h @@ -77,8 +77,27 @@ static __always_inline u32 get_kstack_offset(void) } \ } while (0) +/** + * add_random_kstack_offset_irqsoff - Increase stack utilization by a random offset. + * + * This should be used in the syscall entry path after user registers have been + * stored to the stack. Interrupts must be still disabled. + */ +#define add_random_kstack_offset_irqsoff() \ +do { \ + lockdep_assert_irqs_disabled(); \ + if (static_branch_maybe(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT, \ + &randomize_kstack_offset)) { \ + u32 offset = prandom_u32_state(raw_cpu_ptr(&kstack_rnd_state)); \ + u8 *ptr = __kstack_alloca(KSTACK_OFFSET_MAX(offset)); \ + /* Keep allocation even after "ptr" loses scope. */ \ + asm volatile("" :: "r"(ptr) : "memory"); \ + } \ +} while (0) + #else /* CONFIG_RANDOMIZE_KSTACK_OFFSET */ #define add_random_kstack_offset() do { } while (0) +#define add_random_kstack_offset_irqsoff() do { } while (0) #endif /* CONFIG_RANDOMIZE_KSTACK_OFFSET */ #endif |