[RFC PATCH 02/11] arm64: Move arch-specific prctls out of core code

From: Dave Martin
Date: Mon May 14 2018 - 13:19:40 EST


This patch moves the arm64-specific prctl call implementations out
of core code and removes redundant boilerplate associated with
them.

No functional change.

Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
---
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/processor.h | 4 ----
arch/arm64/kernel/sys.c | 15 +++++++++++++++
kernel/sys.c | 12 ------------
4 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index eb2cf49..6b706af 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -123,6 +123,7 @@ config ARM64
select HAVE_PERF_EVENTS
select HAVE_PERF_REGS
select HAVE_PERF_USER_STACK_DUMP
+ select HAVE_PRCTL_ARCH
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_RCU_TABLE_FREE
select HAVE_SYSCALL_TRACEPOINTS
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index 7675989..b1d262f 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -244,9 +244,5 @@ void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused);
void cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused);
void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused);

-/* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
-#define SVE_SET_VL(arg) sve_set_current_vl(arg)
-#define SVE_GET_VL() sve_get_current_vl()
-
#endif /* __ASSEMBLY__ */
#endif /* __ASM_PROCESSOR_H */
diff --git a/arch/arm64/kernel/sys.c b/arch/arm64/kernel/sys.c
index 72981ba..597ff35 100644
--- a/arch/arm64/kernel/sys.c
+++ b/arch/arm64/kernel/sys.c
@@ -22,10 +22,12 @@
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/export.h>
+#include <linux/prctl.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/syscalls.h>
#include <asm/cpufeature.h>
+#include <asm/fpsimd.h>

asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags,
@@ -45,6 +47,19 @@ SYSCALL_DEFINE1(arm64_personality, unsigned int, personality)
return sys_personality(personality);
}

+int prctl_arch(int option, unsigned long arg2, unsigned long arg3,
+ unsigned long arg4, unsigned long arg5)
+{
+ switch (option) {
+ case PR_SVE_SET_VL:
+ return sve_set_current_vl(arg2);
+ case PR_SVE_GET_VL:
+ return sve_get_current_vl();
+ default:
+ return -EINVAL;
+ }
+}
+
/*
* Wrappers to pass the pt_regs argument.
*/
diff --git a/kernel/sys.c b/kernel/sys.c
index 5077f1e..f917d78 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -113,12 +113,6 @@
#ifndef SET_FP_MODE
# define SET_FP_MODE(a,b) (-EINVAL)
#endif
-#ifndef SVE_SET_VL
-# define SVE_SET_VL(a) (-EINVAL)
-#endif
-#ifndef SVE_GET_VL
-# define SVE_GET_VL() (-EINVAL)
-#endif

/*
* this is where the system-wide overflow UID and GID are defined, for
@@ -2444,12 +2438,6 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
case PR_GET_FP_MODE:
error = GET_FP_MODE(me);
break;
- case PR_SVE_SET_VL:
- error = SVE_SET_VL(arg2);
- break;
- case PR_SVE_GET_VL:
- error = SVE_GET_VL();
- break;
default:
error = prctl_arch(option, arg2, arg3, arg4, arg5);
break;
--
2.1.4