From ddd03a1f7591827906d63dbe3ee003f832bb584f Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 3 Aug 2012 12:12:38 +0400 Subject: get rid of generic instances of asm/exec.h Signed-off-by: Al Viro --- arch/arm/include/asm/Kbuild | 1 + arch/arm/include/asm/exec.h | 6 ------ 2 files changed, 1 insertion(+), 6 deletions(-) delete mode 100644 arch/arm/include/asm/exec.h (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild index 960abceb8e14..7779e389b169 100644 --- a/arch/arm/include/asm/Kbuild +++ b/arch/arm/include/asm/Kbuild @@ -7,6 +7,7 @@ generic-y += bitsperlong.h generic-y += cputime.h generic-y += emergency-restart.h generic-y += errno.h +generic-y += exec.h generic-y += ioctl.h generic-y += irq_regs.h generic-y += kdebug.h diff --git a/arch/arm/include/asm/exec.h b/arch/arm/include/asm/exec.h deleted file mode 100644 index 7c4fbef72b3a..000000000000 --- a/arch/arm/include/asm/exec.h +++ /dev/null @@ -1,6 +0,0 @@ -#ifndef __ASM_ARM_EXEC_H -#define __ASM_ARM_EXEC_H - -#define arch_align_stack(x) (x) - -#endif /* __ASM_ARM_EXEC_H */ -- cgit v1.2.3 From 826eba4db0c643cc0e705c8365902c63fac2b7ee Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 3 Aug 2012 12:14:44 +0400 Subject: the only place that needs to include asm/exec.h is linux/binfmts.h Signed-off-by: Al Viro --- arch/arm/include/asm/system.h | 1 - fs/binfmt_elf.c | 1 - fs/binfmt_elf_fdpic.c | 1 - fs/exec.c | 1 - include/linux/binfmts.h | 1 + 5 files changed, 1 insertion(+), 4 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h index 74542c52f9be..368165e33c1c 100644 --- a/arch/arm/include/asm/system.h +++ b/arch/arm/include/asm/system.h @@ -2,7 +2,6 @@ #include #include #include -#include #include #include #include diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 1b52956afe33..2ab91905b2e2 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -35,7 +35,6 @@ #include #include #include -#include static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs); static int load_elf_library(struct file *); diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 3d77cf81ba3c..c298f2efc1bf 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -39,7 +39,6 @@ #include #include #include -#include typedef char *elf_caddr_t; diff --git a/fs/exec.c b/fs/exec.c index 574cf4de4ec3..d7f9e14f8977 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -59,7 +59,6 @@ #include #include #include -#include #include #include "internal.h" diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index 366422bc1633..8938beabad7a 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -19,6 +19,7 @@ struct pt_regs; #ifdef __KERNEL__ #include +#include #define CORENAME_MAX_SIZE 128 -- cgit v1.2.3 From 9e14f828ee4a7a4a98703e380d180717a579fb35 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 9 Sep 2012 21:31:07 -0400 Subject: arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk] Signed-off-by: Al Viro --- arch/arm/Kconfig | 1 + arch/arm/include/asm/processor.h | 5 --- arch/arm/kernel/entry-common.S | 12 +++++++ arch/arm/kernel/process.c | 75 +++++++--------------------------------- 4 files changed, 26 insertions(+), 67 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 2f88d8d97701..a949eec22861 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -49,6 +49,7 @@ config ARM select GENERIC_STRNCPY_FROM_USER select GENERIC_STRNLEN_USER select DCACHE_WORD_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && !CPU_BIG_ENDIAN + select GENERIC_KERNEL_THREAD 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/processor.h b/arch/arm/include/asm/processor.h index 99afa7498260..06e7d509eaac 100644 --- a/arch/arm/include/asm/processor.h +++ b/arch/arm/include/asm/processor.h @@ -85,11 +85,6 @@ unsigned long get_wchan(struct task_struct *p); #define cpu_relax() barrier() #endif -/* - * Create a new kernel thread - */ -extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); - #define task_pt_regs(p) \ ((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1) diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 978eac57e04a..9a48b7a577e7 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -91,6 +91,18 @@ ENTRY(ret_from_fork) 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) + .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 693b744fd572..c10e4395bc47 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -373,6 +373,7 @@ 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, @@ -381,13 +382,20 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start, struct thread_info *thread = task_thread_info(p); struct pt_regs *childregs = task_pt_regs(p); - *childregs = *regs; - childregs->ARM_r0 = 0; - childregs->ARM_sp = stack_start; - memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); + + if (likely(regs)) { + *childregs = *regs; + childregs->ARM_r0 = 0; + childregs->ARM_sp = stack_start; + thread->cpu_context.pc = (unsigned long)ret_from_fork; + } else { + 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.sp = (unsigned long)childregs; - thread->cpu_context.pc = (unsigned long)ret_from_fork; clear_ptrace_hw_breakpoint(p); @@ -423,63 +431,6 @@ int dump_fpu (struct pt_regs *regs, struct user_fp *fp) } EXPORT_SYMBOL(dump_fpu); -/* - * Shuffle the argument into the correct register before calling the - * thread function. r4 is the thread argument, r5 is the pointer to - * the thread function, and r6 points to the exit function. - */ -extern void kernel_thread_helper(void); -asm( ".pushsection .text\n" -" .align\n" -" .type kernel_thread_helper, #function\n" -"kernel_thread_helper:\n" -#ifdef CONFIG_TRACE_IRQFLAGS -" bl trace_hardirqs_on\n" -#endif -" msr cpsr_c, r7\n" -" mov r0, r4\n" -" mov lr, r6\n" -" mov pc, r5\n" -" .size kernel_thread_helper, . - kernel_thread_helper\n" -" .popsection"); - -#ifdef CONFIG_ARM_UNWIND -extern void kernel_thread_exit(long code); -asm( ".pushsection .text\n" -" .align\n" -" .type kernel_thread_exit, #function\n" -"kernel_thread_exit:\n" -" .fnstart\n" -" .cantunwind\n" -" bl do_exit\n" -" nop\n" -" .fnend\n" -" .size kernel_thread_exit, . - kernel_thread_exit\n" -" .popsection"); -#else -#define kernel_thread_exit do_exit -#endif - -/* - * Create a kernel thread. - */ -pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) -{ - struct pt_regs regs; - - memset(®s, 0, sizeof(regs)); - - regs.ARM_r4 = (unsigned long)arg; - regs.ARM_r5 = (unsigned long)fn; - regs.ARM_r6 = (unsigned long)kernel_thread_exit; - regs.ARM_r7 = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE; - regs.ARM_pc = (unsigned long)kernel_thread_helper; - regs.ARM_cpsr = regs.ARM_r7 | PSR_I_BIT; - - return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); -} -EXPORT_SYMBOL(kernel_thread); - unsigned long get_wchan(struct task_struct *p) { struct stackframe frame; -- cgit v1.2.3 From 583d632fb3f6d7e9d133a7260829dd7565f8cc99 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 2 Aug 2012 11:46:39 +0400 Subject: arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve() Signed-off-by: Al Viro --- arch/arm/include/asm/unistd.h | 1 + arch/arm/kernel/entry-common.S | 12 ++++++++++++ arch/arm/kernel/sys_arm.c | 42 ------------------------------------------ 3 files changed, 13 insertions(+), 42 deletions(-) (limited to 'arch/arm/include') 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(®s, 0, sizeof(struct pt_regs)); - ret = do_execve(filename, - (const char __user *const __user *)argv, - (const char __user *const __user *)envp, ®s); - 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" (®s), - "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. -- cgit v1.2.3 From bfd170d56505bf21cb636b0f1f169eaa815bdfe4 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 2 Aug 2012 11:49:43 +0400 Subject: arm: optimized current_pt_regs() ... no need to read current_thread_info()->task only to feed it to task_thread_page() immediately afterwards. Moreover, not using current_thread_info() at all ends up with better assembler - we need a location very close to the top of kernel stack page and it's actually better to do or with 0x1fff, followed be subtracting a small constant than and with ~0x1fff, followed by adding a large one. Both & and | would be a couple of insns (mvn lsr/mvn lsl for |, a pair of bic for &), but the following addition would cost a pair of add while the subtraction ends up as a single sub. Signed-off-by: Al Viro --- arch/arm/include/asm/ptrace.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h index 355ece523f41..44fe998269d9 100644 --- a/arch/arm/include/asm/ptrace.h +++ b/arch/arm/include/asm/ptrace.h @@ -254,6 +254,11 @@ static inline unsigned long user_stack_pointer(struct pt_regs *regs) return regs->ARM_sp; } +#define current_pt_regs(void) ({ \ + register unsigned long sp asm ("sp"); \ + (struct pt_regs *)((sp | (THREAD_SIZE - 1)) - 7) - 1; \ +}) + #endif /* __KERNEL__ */ #endif /* __ASSEMBLY__ */ -- cgit v1.2.3 From a63c97a000c9c9a03372943a40c3ba8652aa0ccf Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 2 Aug 2012 11:52:41 +0400 Subject: arm: get rid of execve wrapper, switch to generic execve() implementation Signed-off-by: Al Viro --- arch/arm/include/asm/unistd.h | 1 + arch/arm/kernel/calls.S | 2 +- arch/arm/kernel/entry-common.S | 5 ----- arch/arm/kernel/sys_arm.c | 20 -------------------- 4 files changed, 2 insertions(+), 26 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h index 2c9b7a87e64b..6a70aa42debb 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_SYS_EXECVE #define __ARCH_WANT_KERNEL_EXECVE /* diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S index 463ff4a0ec8a..b287b3580a9f 100644 --- a/arch/arm/kernel/calls.S +++ b/arch/arm/kernel/calls.S @@ -20,7 +20,7 @@ CALL(sys_creat) CALL(sys_link) /* 10 */ CALL(sys_unlink) - CALL(sys_execve_wrapper) + CALL(sys_execve) CALL(sys_chdir) CALL(OBSOLETE(sys_time)) /* used by libc4 */ CALL(sys_mknod) diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 4a6e46a9a3d7..ed7941277ca2 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -532,11 +532,6 @@ sys_vfork_wrapper: b sys_vfork ENDPROC(sys_vfork_wrapper) -sys_execve_wrapper: - add r3, sp, #S_OFF - b sys_execve -ENDPROC(sys_execve_wrapper) - sys_clone_wrapper: add ip, sp, #S_OFF str ip, [sp, #4] diff --git a/arch/arm/kernel/sys_arm.c b/arch/arm/kernel/sys_arm.c index c8e729efc187..c2a898aa57aa 100644 --- a/arch/arm/kernel/sys_arm.c +++ b/arch/arm/kernel/sys_arm.c @@ -59,26 +59,6 @@ asmlinkage int sys_vfork(struct pt_regs *regs) return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL); } -/* sys_execve() executes a new program. - * This is called indirectly via a small wrapper - */ -asmlinkage int sys_execve(const char __user *filenamei, - const char __user *const __user *argv, - const char __user *const __user *envp, struct pt_regs *regs) -{ - int error; - char * filename; - - filename = getname(filenamei); - error = PTR_ERR(filename); - if (IS_ERR(filename)) - goto out; - error = do_execve(filename, argv, envp, regs); - putname(filename); -out: - return error; -} - /* * Since loff_t is a 64 bit type we avoid a lot of ABI hassle * with a different argument ordering. -- cgit v1.2.3