infrastructure for saner ret_from_kernel_thread semantics
* allow kernel_execve() leave the actual return to userland to
caller (selected by CONFIG_GENERIC_KERNEL_EXECVE). Callers
updated accordingly.
* architecture that does select GENERIC_KERNEL_EXECVE in its
Kconfig should have its ret_from_kernel_thread() do this:
call schedule_tail
call the callback left for it by copy_thread(); if it ever
returns, that's because it has just done successful kernel_execve()
jump to return from syscall
IOW, its only difference from ret_from_fork() is that it does call the
callback.
* such an architecture should also get rid of ret_from_kernel_execve()
and __ARCH_WANT_KERNEL_EXECVE
This is the last part of infrastructure patches in that area - from
that point on work on different architectures can live independently.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 19439c7..727f0cd 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -827,7 +827,15 @@
const char __user *pathname);
asmlinkage long sys_syncfs(int fd);
+#ifndef CONFIG_GENERIC_KERNEL_EXECVE
int kernel_execve(const char *filename, const char *const argv[], const char *const envp[]);
+#else
+#define kernel_execve(filename, argv, envp) \
+ do_execve(filename, \
+ (const char __user *const __user *)argv, \
+ (const char __user *const __user *)envp, \
+ current_pt_regs())
+#endif
asmlinkage long sys_perf_event_open(