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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2008-07-22 17:12:37 +1000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2008-07-22 17:12:37 +1000
commit8725f25acc656c1522d48a6746055099efdaca4c (patch)
treee241424fa58178ed6c2a95a4eb931ea83dbea33c /arch/mips/kernel/syscall.c
parentc69cccc95fe4b90dde5fe33e6a3b77880b534fa4 (diff)
parent93ded9b8fd42abe2c3607097963d8de6ad9117eb (diff)
Merge commit 'origin/master'
Manually fixed up: drivers/net/fs_enet/fs_enet-main.c
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;