[PATCH RFT v12 1/8] arm64/gcs: Return a success value from gcs_alloc_thread_stack()

[Mark Brown]

Currently as a result of templating from x86 code gcs_alloc_thread_stack()
returns a pointer as an unsigned int however on arm64 we don't actually use
this pointer value as anything other than a pass/fail flag. Simplify the
interface to just return an int with 0 on success and a negative error code
on failure.

Acked-by: Deepak Gupta <de...@rivosinc.com>
Signed-off-by: Mark Brown <broo...@kernel.org>
---
 arch/arm64/include/asm/gcs.h | 8 ++++----
 arch/arm64/kernel/process.c  | 8 ++++----
 arch/arm64/mm/gcs.c          | 8 ++++----
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/include/asm/gcs.h b/arch/arm64/include/asm/gcs.h
index 
f50660603ecf5dc09a92740062df3a089b02b219..d8923b5f03b776252aca76ce316ef57399d71fa9
 100644
--- a/arch/arm64/include/asm/gcs.h
+++ b/arch/arm64/include/asm/gcs.h
@@ -64,8 +64,8 @@ static inline bool task_gcs_el0_enabled(struct task_struct 
*task)
 void gcs_set_el0_mode(struct task_struct *task);
 void gcs_free(struct task_struct *task);
 void gcs_preserve_current_state(void);
-unsigned long gcs_alloc_thread_stack(struct task_struct *tsk,
-                                    const struct kernel_clone_args *args);
+int gcs_alloc_thread_stack(struct task_struct *tsk,
+                          const struct kernel_clone_args *args);
 
 static inline int gcs_check_locked(struct task_struct *task,
                                   unsigned long new_val)
@@ -91,8 +91,8 @@ static inline bool task_gcs_el0_enabled(struct task_struct 
*task)
 static inline void gcs_set_el0_mode(struct task_struct *task) { }
 static inline void gcs_free(struct task_struct *task) { }
 static inline void gcs_preserve_current_state(void) { }
-static inline unsigned long gcs_alloc_thread_stack(struct task_struct *tsk,
-                                                  const struct 
kernel_clone_args *args)
+static inline int gcs_alloc_thread_stack(struct task_struct *tsk,
+                                        const struct kernel_clone_args *args)
 {
        return -ENOTSUPP;
 }
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 
fdd095480c3ffb8c13fd4e7c9abc79e88143e08b..8ebd11c29792524dfeeade9cc7826b007329aa6a
 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -297,7 +297,7 @@ static void flush_gcs(void)
 static int copy_thread_gcs(struct task_struct *p,
                           const struct kernel_clone_args *args)
 {
-       unsigned long gcs;
+       int ret;
 
        if (!system_supports_gcs())
                return 0;
@@ -305,9 +305,9 @@ static int copy_thread_gcs(struct task_struct *p,
        p->thread.gcs_base = 0;
        p->thread.gcs_size = 0;
 
-       gcs = gcs_alloc_thread_stack(p, args);
-       if (IS_ERR_VALUE(gcs))
-               return PTR_ERR((void *)gcs);
+       ret = gcs_alloc_thread_stack(p, args);
+       if (ret != 0)
+               return ret;
 
        p->thread.gcs_el0_mode = current->thread.gcs_el0_mode;
        p->thread.gcs_el0_locked = current->thread.gcs_el0_locked;
diff --git a/arch/arm64/mm/gcs.c b/arch/arm64/mm/gcs.c
index 
5c46ec527b1cdaa8f52cff445d70ba0f8509d086..1f633a482558b59aac5427963d42b37fce08c8a6
 100644
--- a/arch/arm64/mm/gcs.c
+++ b/arch/arm64/mm/gcs.c
@@ -38,8 +38,8 @@ static unsigned long gcs_size(unsigned long size)
        return max(PAGE_SIZE, size);
 }
 
-unsigned long gcs_alloc_thread_stack(struct task_struct *tsk,
-                                    const struct kernel_clone_args *args)
+int gcs_alloc_thread_stack(struct task_struct *tsk,
+                          const struct kernel_clone_args *args)
 {
        unsigned long addr, size;
 
@@ -59,13 +59,13 @@ unsigned long gcs_alloc_thread_stack(struct task_struct 
*tsk,
        size = gcs_size(size);
        addr = alloc_gcs(0, size);
        if (IS_ERR_VALUE(addr))
-               return addr;
+               return PTR_ERR((void *)addr);
 
        tsk->thread.gcs_base = addr;
        tsk->thread.gcs_size = size;
        tsk->thread.gcspr_el0 = addr + size - sizeof(u64);
 
-       return addr;
+       return 0;
 }
 
 SYSCALL_DEFINE3(map_shadow_stack, unsigned long, addr, unsigned long, size, 
unsigned int, flags)

-- 
2.39.2