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authorIngo Molnar <mingo@elte.hu>2008-07-21 15:06:09 +0200
committerIngo Molnar <mingo@elte.hu>2008-07-21 15:06:09 +0200
commite66d90fb4abd0a27ee96f57a32fb561221c4d6ae (patch)
tree3337cba94c7444b06fdb0e8b487287d07b71f4a0 /arch/mips/kernel/syscall.c
parent55ca089e2579de90f048aca2a3030b8b2f864813 (diff)
parent14b395e35d1afdd8019d11b92e28041fad591b71 (diff)
Merge branch 'linus' into xen-64bit
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 af1bdc897488..3523c8d12eda 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;