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| author | Al Viro <viro@zeniv.linux.org.uk> | 2012-10-10 22:23:29 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-10-12 13:35:23 -0400 |
| commit | 9fff2fa0db911b0b75ec1f9bec72460c0a676ef5 (patch) | |
| tree | 38fd00adc9bde62de1d5f6346dc670e0e599068f /arch | |
| parent | 22e2430d60dbdfcdd732a086e9ef2dbd74c266d1 (diff) | |
| download | lwn-9fff2fa0db911b0b75ec1f9bec72460c0a676ef5.tar.gz lwn-9fff2fa0db911b0b75ec1f9bec72460c0a676ef5.zip | |
arm: switch to saner kernel_execve() semantics
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm/include/asm/unistd.h | 1 | ||||
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 29 | ||||
| -rw-r--r-- | arch/arm/kernel/process.c | 5 |
4 files changed, 7 insertions, 29 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index a949eec22861..ea3ad0641952 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 6a70aa42debb..984ad42ed0af 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 ed7941277ca2..91069666af9f 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 c10e4395bc47..0f83fa2e58e3 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); |