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authorIngo Molnar <mingo@elte.hu>2008-07-21 15:05:58 +0200
committerIngo Molnar <mingo@elte.hu>2008-07-21 15:05:58 +0200
commit1c29dd9a9e2f83ffb02e50bb3619c3b9db8fd526 (patch)
treeb5691dd5aa48ac32fdbaef44afcbcc92f01592d3 /arch/mips/kernel/syscall.c
parent32172561889868c0ea422ea8570f0413963a815f (diff)
parent14b395e35d1afdd8019d11b92e28041fad591b71 (diff)
Merge branch 'linus' into x86/paravirt-spinlocks
Diffstat (limited to 'arch/mips/kernel/syscall.c')
-rw-r--r--arch/mips/kernel/syscall.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index af1bdc89748..3523c8d12ed 100644
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -40,7 +40,14 @@
#include <asm/sysmips.h>
#include <asm/uaccess.h>
-asmlinkage int sys_pipe(nabi_no_regargs volatile struct pt_regs regs)
+/*
+ * For historic reasons the pipe(2) syscall on MIPS has an unusual calling
+ * convention. It returns results in registers $v0 / $v1 which means there
+ * is no need for it to do verify the validity of a userspace pointer
+ * argument. Historically that used to be expensive in Linux. These days
+ * the performance advantage is negligible.
+ */
+asmlinkage int sysm_pipe(nabi_no_regargs volatile struct pt_regs regs)
{
int fd[2];
int error, res;