2022-01-14 11:26:29

by Christophe Leroy

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

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 <[email protected]>
Fixes: 770cec16cdc9 ("powerpc/audit: Simplify syscall_get_arch()")
Fixes: 898a1ef06ad4 ("powerpc/audit: Avoid unneccessary #ifdef in syscall_get_arguments()")
Cc: [email protected]
Signed-off-by: Christophe Leroy <[email protected]>
---
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

2022-01-17 05:37:48

by Michael Ellerman

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

On Fri, 14 Jan 2022 11:26:25 +0000, Christophe Leroy wrote:
> 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'
>
> [...]

Applied to powerpc/fixes.

[1/1] powerpc/audit: Fix syscall_get_arch()
https://git.kernel.org/powerpc/c/252745240ba0ae774d2f80c5e185ed59fbc4fb41

cheers