[PATCH v2] powerpc/audit: Fix syscall_get_arch()

[Christophe Leroy]

Commit 770cec16cdc9 ("powerpc/audit: Simplify syscall_get_arch()")
and commit 898a1ef06ad4 ("powerpc/audit: Avoid unneccessary #ifdef
in syscall_get_arguments()")
replaced test_tsk_thread_flag(task, TIF_32BIT)) by is_32bit_task().

But is_32bit_task() applies on current task while be want the test
done on task 'task'

So add a new macro is_tsk_32bit_task() to check any task.

Reported-by: Dmitry V. Levin <l...@altlinux.org>
Fixes: 770cec16cdc9 ("powerpc/audit: Simplify syscall_get_arch()")
Fixes: 898a1ef06ad4 ("powerpc/audit: Avoid unneccessary #ifdef in 
syscall_get_arguments()")
Cc: sta...@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
v2: Add new macro and handle second erroneous use of is_32bit_task().
---
 arch/powerpc/include/asm/syscall.h     | 4 ++--
 arch/powerpc/include/asm/thread_info.h | 2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/syscall.h 
b/arch/powerpc/include/asm/syscall.h
index 52d05b465e3e..25fc8ad9a27a 100644
--- a/arch/powerpc/include/asm/syscall.h
+++ b/arch/powerpc/include/asm/syscall.h
@@ -90,7 +90,7 @@ static inline void syscall_get_arguments(struct task_struct 
*task,
        unsigned long val, mask = -1UL;
        unsigned int n = 6;
 
-       if (is_32bit_task())
+       if (is_tsk_32bit_task(task))
                mask = 0xffffffff;
 
        while (n--) {
@@ -105,7 +105,7 @@ static inline void syscall_get_arguments(struct task_struct 
*task,
 
 static inline int syscall_get_arch(struct task_struct *task)
 {
-       if (is_32bit_task())
+       if (is_tsk_32bit_task(task))
                return AUDIT_ARCH_PPC;
        else if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN))
                return AUDIT_ARCH_PPC64LE;
diff --git a/arch/powerpc/include/asm/thread_info.h 
b/arch/powerpc/include/asm/thread_info.h
index 5725029aaa29..d6e649b3c70b 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -168,8 +168,10 @@ static inline bool test_thread_local_flags(unsigned int 
flags)
 
 #ifdef CONFIG_COMPAT
 #define is_32bit_task()        (test_thread_flag(TIF_32BIT))
+#define is_tsk_32bit_task(tsk) (test_tsk_thread_flag(tsk, TIF_32BIT))
 #else
 #define is_32bit_task()        (IS_ENABLED(CONFIG_PPC32))
+#define is_tsk_32bit_task(tsk) (IS_ENABLED(CONFIG_PPC32))
 #endif
 
 #if defined(CONFIG_PPC64)
-- 
2.33.1