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authorAl Viro <viro@zeniv.linux.org.uk>2012-08-02 11:46:39 +0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-09-30 22:21:36 -0400
commit583d632fb3f6d7e9d133a7260829dd7565f8cc99 (patch)
tree57760f02b8f9aa876a08e309f0ff258442bfa639 /arch/arm
parent9e14f828ee4a7a4a98703e380d180717a579fb35 (diff)
downloadlinux-linaro-stable-583d632fb3f6d7e9d133a7260829dd7565f8cc99.tar.gz
arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/unistd.h1
-rw-r--r--arch/arm/kernel/entry-common.S12
-rw-r--r--arch/arm/kernel/sys_arm.c42
3 files changed, 13 insertions, 42 deletions
diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h
index 0cab47d4a83f..2c9b7a87e64b 100644
--- a/arch/arm/include/asm/unistd.h
+++ b/arch/arm/include/asm/unistd.h
@@ -469,6 +469,7 @@
#define __ARCH_WANT_OLD_READDIR
#define __ARCH_WANT_SYS_SOCKETCALL
#endif
+#define __ARCH_WANT_KERNEL_EXECVE
/*
* "Conditional" syscalls
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 9a48b7a577e7..4a6e46a9a3d7 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -103,6 +103,18 @@ ENTRY(ret_from_kernel_thread)
UNWIND(.fnend)
ENDPROC(ret_from_kernel_thread)
+/*
+ * turn a kernel thread into userland process
+ * use: ret_from_kernel_execve(struct pt_regs *normal)
+ */
+ENTRY(ret_from_kernel_execve)
+ mov why, #0 @ not a syscall
+ str why, [r0, #S_R0] @ ... and we want 0 in ->ARM_r0 as well
+ get_thread_info tsk @ thread structure
+ mov sp, r0 @ stack pointer just under pt_regs
+ b ret_slow_syscall
+ENDPROC(ret_from_kernel_execve)
+
.equ NR_syscalls,0
#define CALL(x) .equ NR_syscalls,NR_syscalls+1
#include "calls.S"
diff --git a/arch/arm/kernel/sys_arm.c b/arch/arm/kernel/sys_arm.c
index 3ba62e3cd1a2..c8e729efc187 100644
--- a/arch/arm/kernel/sys_arm.c
+++ b/arch/arm/kernel/sys_arm.c
@@ -79,48 +79,6 @@ out:
return error;
}
-int kernel_execve(const char *filename,
- const char *const argv[],
- const char *const envp[])
-{
- struct pt_regs regs;
- int ret;
-
- memset(&regs, 0, sizeof(struct pt_regs));
- ret = do_execve(filename,
- (const char __user *const __user *)argv,
- (const char __user *const __user *)envp, &regs);
- if (ret < 0)
- goto out;
-
- /*
- * Save argc to the register structure for userspace.
- */
- regs.ARM_r0 = ret;
-
- /*
- * We were successful. We won't be returning to our caller, but
- * instead to user space by manipulating the kernel stack.
- */
- asm( "add r0, %0, %1\n\t"
- "mov r1, %2\n\t"
- "mov r2, %3\n\t"
- "bl memmove\n\t" /* copy regs to top of stack */
- "mov r8, #0\n\t" /* not a syscall */
- "mov r9, %0\n\t" /* thread structure */
- "mov sp, r0\n\t" /* reposition stack pointer */
- "b ret_to_user"
- :
- : "r" (current_thread_info()),
- "Ir" (THREAD_START_SP - sizeof(regs)),
- "r" (&regs),
- "Ir" (sizeof(regs))
- : "r0", "r1", "r2", "r3", "r8", "r9", "ip", "lr", "memory");
-
- out:
- return ret;
-}
-
/*
* Since loff_t is a 64 bit type we avoid a lot of ABI hassle
* with a different argument ordering.