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authorLinus Torvalds <torvalds@linux-foundation.org>2012-10-10 12:02:25 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-10 12:02:25 +0900
commit42859eea96ba6beabfb0369a1eeffa3c7d2bd9cb (patch)
treefa38aeda0d6e7a4c48a882b166b8643594a1ad50 /arch/x86/kernel/process_32.c
parentf59b51fe3d3092c08d7d554ecb40db24011b2ebc (diff)
parentf322220d6159455da2b5a8a596d802c8695fed30 (diff)
downloadtalos-obmc-linux-42859eea96ba6beabfb0369a1eeffa3c7d2bd9cb.tar.gz
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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull generic execve() changes from Al Viro: "This introduces the generic kernel_thread() and kernel_execve() functions, and switches x86, arm, alpha, um and s390 over to them." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits) s390: convert to generic kernel_execve() s390: switch to generic kernel_thread() s390: fold kernel_thread_helper() into ret_from_fork() s390: fold execve_tail() into start_thread(), convert to generic sys_execve() um: switch to generic kernel_thread() x86, um/x86: switch to generic sys_execve and kernel_execve x86: split ret_from_fork alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve() alpha: switch to generic kernel_thread() alpha: switch to generic sys_execve() arm: get rid of execve wrapper, switch to generic execve() implementation arm: optimized current_pt_regs() arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve() arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk] generic sys_execve() generic kernel_execve() new helper: current_pt_regs() preparation for generic kernel_thread() um: kill thread->forking um: let signal_delivered() do SIGTRAP on singlestepping into handler ...
Diffstat (limited to 'arch/x86/kernel/process_32.c')
-rw-r--r--arch/x86/kernel/process_32.c37
1 files changed, 30 insertions, 7 deletions
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index b9ff83c7135b..44e0bff38e72 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -57,6 +57,7 @@
#include <asm/switch_to.h>
asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
+asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");
/*
* Return saved PC of a blocked thread.
@@ -127,23 +128,39 @@ void release_thread(struct task_struct *dead_task)
}
int copy_thread(unsigned long clone_flags, unsigned long sp,
- unsigned long unused,
+ unsigned long arg,
struct task_struct *p, struct pt_regs *regs)
{
- struct pt_regs *childregs;
+ struct pt_regs *childregs = task_pt_regs(p);
struct task_struct *tsk;
int err;
- childregs = task_pt_regs(p);
+ p->thread.sp = (unsigned long) childregs;
+ p->thread.sp0 = (unsigned long) (childregs+1);
+
+ if (unlikely(!regs)) {
+ /* kernel thread */
+ memset(childregs, 0, sizeof(struct pt_regs));
+ p->thread.ip = (unsigned long) ret_from_kernel_thread;
+ task_user_gs(p) = __KERNEL_STACK_CANARY;
+ childregs->ds = __USER_DS;
+ childregs->es = __USER_DS;
+ childregs->fs = __KERNEL_PERCPU;
+ childregs->bx = sp; /* function */
+ childregs->bp = arg;
+ childregs->orig_ax = -1;
+ childregs->cs = __KERNEL_CS | get_kernel_rpl();
+ childregs->flags = X86_EFLAGS_IF | X86_EFLAGS_BIT1;
+ p->fpu_counter = 0;
+ p->thread.io_bitmap_ptr = NULL;
+ memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
+ return 0;
+ }
*childregs = *regs;
childregs->ax = 0;
childregs->sp = sp;
- p->thread.sp = (unsigned long) childregs;
- p->thread.sp0 = (unsigned long) (childregs+1);
-
p->thread.ip = (unsigned long) ret_from_fork;
-
task_user_gs(p) = get_user_gs(regs);
p->fpu_counter = 0;
@@ -190,6 +207,12 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
regs->cs = __USER_CS;
regs->ip = new_ip;
regs->sp = new_sp;
+ regs->flags = X86_EFLAGS_IF;
+ /*
+ * force it to the iret return path by making it look as if there was
+ * some work pending.
+ */
+ set_thread_flag(TIF_NOTIFY_RESUME);
}
EXPORT_SYMBOL_GPL(start_thread);
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