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authorAl Viro <viro@zeniv.linux.org.uk>2012-10-10 22:23:29 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-10-12 13:35:23 -0400
commit9fff2fa0db911b0b75ec1f9bec72460c0a676ef5 (patch)
tree38fd00adc9bde62de1d5f6346dc670e0e599068f
parent22e2430d60dbdfcdd732a086e9ef2dbd74c266d1 (diff)
arm: switch to saner kernel_execve() semantics
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--arch/arm/Kconfig1
-rw-r--r--arch/arm/include/asm/unistd.h1
-rw-r--r--arch/arm/kernel/entry-common.S29
-rw-r--r--arch/arm/kernel/process.c5
4 files changed, 7 insertions, 29 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a949eec2286..ea3ad064195 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -50,6 +50,7 @@ config ARM
select GENERIC_STRNLEN_USER
select DCACHE_WORD_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && !CPU_BIG_ENDIAN
select GENERIC_KERNEL_THREAD
+ select GENERIC_KERNEL_EXECVE
help
The ARM series is a line of low-power-consumption RISC chip designs
licensed by ARM Ltd and targeted at embedded applications and
diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h
index 6a70aa42deb..984ad42ed0a 100644
--- a/arch/arm/include/asm/unistd.h
+++ b/arch/arm/include/asm/unistd.h
@@ -470,7 +470,6 @@
#define __ARCH_WANT_SYS_SOCKETCALL
#endif
#define __ARCH_WANT_SYS_EXECVE
-#define __ARCH_WANT_KERNEL_EXECVE
/*
* "Conditional" syscalls
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index ed7941277ca..91069666af9 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -86,35 +86,14 @@ ENDPROC(ret_to_user)
*/
ENTRY(ret_from_fork)
bl schedule_tail
+ cmp r5, #0
+ movne r0, r4
+ movne lr, pc
+ movne pc, r5
get_thread_info tsk
- mov why, #1
b ret_slow_syscall
ENDPROC(ret_from_fork)
-ENTRY(ret_from_kernel_thread)
- UNWIND(.fnstart)
- UNWIND(.cantunwind)
- bl schedule_tail
- mov r0, r4
- adr lr, BSYM(1f) @ kernel threads should not exit
- mov pc, r5
-1: bl do_exit
- nop
- 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/process.c b/arch/arm/kernel/process.c
index c10e4395bc4..0f83fa2e58e 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -373,7 +373,6 @@ void release_thread(struct task_struct *dead_task)
}
asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
-asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");
int
copy_thread(unsigned long clone_flags, unsigned long stack_start,
@@ -388,13 +387,13 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start,
*childregs = *regs;
childregs->ARM_r0 = 0;
childregs->ARM_sp = stack_start;
- thread->cpu_context.pc = (unsigned long)ret_from_fork;
} else {
+ memset(childregs, 0, sizeof(struct pt_regs));
thread->cpu_context.r4 = stk_sz;
thread->cpu_context.r5 = stack_start;
- thread->cpu_context.pc = (unsigned long)ret_from_kernel_thread;
childregs->ARM_cpsr = SVC_MODE;
}
+ thread->cpu_context.pc = (unsigned long)ret_from_fork;
thread->cpu_context.sp = (unsigned long)childregs;
clear_ptrace_hw_breakpoint(p);