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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-11-02 00:48:19 (GMT) |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-11-02 00:48:19 (GMT) |
| commit | c660b8f944f1815494a76935148571276fa47462 (patch) | |
| tree | a6b98740870bb455e477782ad46c4a7d3892f1da /arch/xtensa/kernel/entry.S | |
| parent | 8c23f406c6d86808726ace580657186bc3b44587 (diff) | |
| parent | dc241f2c1761bfdec85915f4bbf7e750663f3442 (diff) | |
| download | linux-c660b8f944f1815494a76935148571276fa47462.tar.xz | |
Merge tag 'xtensa-next-20121101' of git://github.com/czankel/xtensa-linux
Pull Xtensa fixes from Chris Zankel:
"Some important bug fixes.
With the change to uapi, there was a bug introduced that results in an
empty syscall table (mult-inclusion bug). Switching to the generic
thread/execve allowed us to fix a bug we had in vfork()."
* tag 'xtensa-next-20121101' of git://github.com/czankel/xtensa-linux:
xtensa: switch to generic sys_execve()
xtensa: switch to generic kernel_execve()
xtensa: switch to generic kernel_thread()
xtensa: reset windowbase/windowstart when cloning the VM
xtensa: use physical addresses for bus addresses
xtensa: allow multi-inclusion for uapi/unistd.h
Diffstat (limited to 'arch/xtensa/kernel/entry.S')
| -rw-r--r-- | arch/xtensa/kernel/entry.S | 57 |
1 files changed, 13 insertions, 44 deletions
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index 18453067..90bfc1d 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -1833,50 +1833,6 @@ ENTRY(system_call) /* - * Create a kernel thread - * - * int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) - * a2 a2 a3 a4 - */ - -ENTRY(kernel_thread) - entry a1, 16 - - mov a5, a2 # preserve fn over syscall - mov a7, a3 # preserve args over syscall - - movi a3, _CLONE_VM | _CLONE_UNTRACED - movi a2, __NR_clone - or a6, a4, a3 # arg0: flags - mov a3, a1 # arg1: sp - syscall - - beq a3, a1, 1f # branch if parent - mov a6, a7 # args - callx4 a5 # fn(args) - - movi a2, __NR_exit - syscall # return value of fn(args) still in a6 - -1: retw - -/* - * Do a system call from kernel instead of calling sys_execve, so we end up - * with proper pt_regs. - * - * int kernel_execve(const char *fname, char *const argv[], charg *const envp[]) - * a2 a2 a3 a4 - */ - -ENTRY(kernel_execve) - entry a1, 16 - mov a6, a2 # arg0 is in a6 - movi a2, __NR_execve - syscall - - retw - -/* * Task switch. * * struct task* _switch_to (struct task* prev, struct task* next) @@ -1958,3 +1914,16 @@ ENTRY(ret_from_fork) j common_exception_return +/* + * Kernel thread creation helper + * On entry, set up by copy_thread: a2 = thread_fn, a3 = thread_fn arg + * left from _switch_to: a6 = prev + */ +ENTRY(ret_from_kernel_thread) + + call4 schedule_tail + mov a6, a3 + callx4 a2 + j common_exception_return + +ENDPROC(ret_from_kernel_thread) |