[tip: x86/cleanups] x86/prctl: Remove pointless task argument

tip-bot2 for Thomas Gleixner
2022-05-13T12:30:22Z

The following commit has been merged into the x86/cleanups branch of tip:

Commit-ID: f5c0b4f30416c670408a77be94703d04d22b57df
Gitweb: https://git.kernel.org/tip/f5c0b4f30416c670408a77be94703d04d22b57df
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Thu, 12 May 2022 14:04:08 +02:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Fri, 13 May 2022 12:56:28 +02:00

x86/prctl: Remove pointless task argument

The functions invoked via do_arch_prctl_common() can only operate on
the current task and none of these function uses the task argument.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/87lev7vtxj.ffs@tglx
---
arch/x86/include/asm/fpu/api.h | 3 +--
arch/x86/include/asm/proto.h | 3 +--
arch/x86/kernel/fpu/xstate.c | 5 +----
arch/x86/kernel/process.c | 9 ++++-----
arch/x86/kernel/process_32.c | 2 +-
arch/x86/kernel/process_64.c | 4 ++--
6 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h
index c83b302..6b0f31f 100644
--- a/arch/x86/include/asm/fpu/api.h
+++ b/arch/x86/include/asm/fpu/api.h
@@ -162,7 +162,6 @@ static inline bool fpstate_is_confidential(struct fpu_guest *gfpu)
}

/* prctl */
-struct task_struct;
-extern long fpu_xstate_prctl(struct task_struct *tsk, int option, unsigned long arg2);
+extern long fpu_xstate_prctl(int option, unsigned long arg2);

#endif /* _ASM_X86_FPU_API_H */
diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h
index feed36d..80be803 100644
--- a/arch/x86/include/asm/proto.h
+++ b/arch/x86/include/asm/proto.h
@@ -39,7 +39,6 @@ void x86_report_nx(void);

extern int reboot_force;

-long do_arch_prctl_common(struct task_struct *task, int option,
- unsigned long arg2);
+long do_arch_prctl_common(int option, unsigned long arg2);

#endif /* _ASM_X86_PROTO_H */
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 39e1c86..1b016a1 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -1687,16 +1687,13 @@ EXPORT_SYMBOL_GPL(xstate_get_guest_group_perm);
* e.g. for AMX which requires XFEATURE_XTILE_CFG(17) and
* XFEATURE_XTILE_DATA(18) this would be XFEATURE_XTILE_DATA(18).
*/
-long fpu_xstate_prctl(struct task_struct *tsk, int option, unsigned long arg2)
+long fpu_xstate_prctl(int option, unsigned long arg2)
{
u64 __user *uptr = (u64 __user *)arg2;
u64 permitted, supported;
unsigned long idx = arg2;
bool guest = false;

- if (tsk != current)
- return -EPERM;
-
switch (option) {
case ARCH_GET_XCOMP_SUPP:
supported = fpu_user_cfg.max_features | fpu_user_cfg.legacy_features;
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index b3d2d41..e86d09a 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -334,7 +334,7 @@ static int get_cpuid_mode(void)
return !test_thread_flag(TIF_NOCPUID);
}

-static int set_cpuid_mode(struct task_struct *task, unsigned long cpuid_enabled)
+static int set_cpuid_mode(unsigned long cpuid_enabled)
{
if (!boot_cpu_has(X86_FEATURE_CPUID_FAULT))
return -ENODEV;
@@ -985,20 +985,19 @@ unsigned long __get_wchan(struct task_struct *p)
return addr;
}

-long do_arch_prctl_common(struct task_struct *task, int option,
- unsigned long arg2)
+long do_arch_prctl_common(int option, unsigned long arg2)
{
switch (option) {
case ARCH_GET_CPUID:
return get_cpuid_mode();
case ARCH_SET_CPUID:
- return set_cpuid_mode(task, arg2);
+ return set_cpuid_mode(arg2);
case ARCH_GET_XCOMP_SUPP:
case ARCH_GET_XCOMP_PERM:
case ARCH_REQ_XCOMP_PERM:
case ARCH_GET_XCOMP_GUEST_PERM:
case ARCH_REQ_XCOMP_GUEST_PERM:
- return fpu_xstate_prctl(task, option, arg2);
+ return fpu_xstate_prctl(option, arg2);
}

return -EINVAL;
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 26edb1c..0faa5e2 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -222,5 +222,5 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)

SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
{
- return do_arch_prctl_common(current, option, arg2);
+ return do_arch_prctl_common(option, arg2);
}
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index e459253..1962008 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -844,7 +844,7 @@ SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)

ret = do_arch_prctl_64(current, option, arg2);
if (ret == -EINVAL)
- ret = do_arch_prctl_common(current, option, arg2);
+ ret = do_arch_prctl_common(option, arg2);

return ret;
}
@@ -852,7 +852,7 @@ SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
#ifdef CONFIG_IA32_EMULATION
COMPAT_SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
{
- return do_arch_prctl_common(current, option, arg2);
+ return do_arch_prctl_common(option, arg2);
}
#endif