The memory management (mm) subsystem is a fundamental low-level component
of the Linux kernel. Establishing const-correctness at this foundational
level enables higher-level subsystems, such as filesystems and drivers,
to also adopt const-correctness in their interfaces. This patch lays
the groundwork for broader const-correctness throughout the kernel
by starting with the core mm subsystem.
This patch adds const qualifiers to task_struct and mm_struct pointer
parameters in the OOM killer code that do not modify the referenced
memory, improving type safety and enabling compiler optimizations.
Functions improved:
- process_shares_mm()
Signed-off-by: Max Kellermann <max.kellermann@xxxxxxxxx>
---
include/linux/mm.h | 2 +-
mm/oom_kill.c | 3 ++-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 18deb14cb1f5..f70c6b4d5f80 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3840,7 +3840,7 @@ static inline int in_gate_area(struct mm_struct *mm, unsigned long addr)
}
#endif /* __HAVE_ARCH_GATE_AREA */
-extern bool process_shares_mm(struct task_struct *p, struct mm_struct *mm);
+bool process_shares_mm(const struct task_struct *p, const struct mm_struct *mm);
void drop_slab(void);
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 17650f0b516e..2620b32a8eba 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -490,7 +490,8 @@ static bool oom_killer_disabled __read_mostly;
* task's threads: if one of those is using this mm then this task was also
* using it.
*/
-bool process_shares_mm(struct task_struct *p, struct mm_struct *mm)
+bool process_shares_mm(const struct task_struct *const p,
+ const struct mm_struct *const mm)
{
struct task_struct *t;
--
2.47.2
