From 601cc11d054ae4b5e9b5babec3d8e4667a2cb9b5 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 3 Apr 2009 08:03:22 -0700 Subject: Make non-compat preadv/pwritev use native register size Instead of always splitting the file offset into 32-bit 'high' and 'low' parts, just split them into the largest natural word-size - which in C terms is 'unsigned long'. This allows 64-bit architectures to avoid the unnecessary 32-bit shifting and masking for native format (while the compat interfaces will obviously always have to do it). This also changes the order of 'high' and 'low' to be "low first". Why? Because when we have it like this, the 64-bit system calls now don't use the "pos_high" argument at all, and it makes more sense for the native system call to simply match the user-mode prototype. This results in a much more natural calling convention, and allows the compiler to generate much more straightforward code. On x86-64, we now generate testq %rcx, %rcx # pos_l js .L122 #, movq %rcx, -48(%rbp) # pos_l, pos from the C source loff_t pos = pos_from_hilo(pos_h, pos_l); ... if (pos < 0) return -EINVAL; and the 'pos_h' register isn't even touched. It used to generate code like mov %r8d, %r8d # pos_low, pos_low salq $32, %rcx #, tmp71 movq %r8, %rax # pos_low, pos.386 orq %rcx, %rax # tmp71, pos.386 js .L122 #, movq %rax, -48(%rbp) # pos.386, pos which isn't _that_ horrible, but it does show how the natural word size is just a more sensible interface (same arguments will hold in the user level glibc wrapper function, of course, so the kernel side is just half of the equation!) Note: in all cases the user code wrapper can again be the same. You can just do #define HALF_BITS (sizeof(unsigned long)*4) __syscall(PWRITEV, fd, iov, count, offset, (offset >> HALF_BITS) >> HALF_BITS); or something like that. That way the user mode wrapper will also be nicely passing in a zero (it won't actually have to do the shifts, the compiler will understand what is going on) for the last argument. And that is a good idea, even if nobody will necessarily ever care: if we ever do move to a 128-bit lloff_t, this particular system call might be left alone. Of course, that will be the least of our worries if we really ever need to care, so this may not be worth really caring about. [ Fixed for lost 'loff_t' cast noticed by Andrew Morton ] Acked-by: Gerd Hoffmann Cc: H. Peter Anvin Cc: Andrew Morton Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: Ingo Molnar Cc: Ralf Baechle > Cc: Al Viro Signed-off-by: Linus Torvalds --- fs/compat.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/compat.c') diff --git a/fs/compat.c b/fs/compat.c index 1c859dae758..3f84d5f1588 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -1236,7 +1236,7 @@ compat_sys_readv(unsigned long fd, const struct compat_iovec __user *vec, asmlinkage ssize_t compat_sys_preadv(unsigned long fd, const struct compat_iovec __user *vec, - unsigned long vlen, u32 pos_high, u32 pos_low) + unsigned long vlen, u32 pos_low, u32 pos_high) { loff_t pos = ((loff_t)pos_high << 32) | pos_low; struct file *file; @@ -1293,7 +1293,7 @@ compat_sys_writev(unsigned long fd, const struct compat_iovec __user *vec, asmlinkage ssize_t compat_sys_pwritev(unsigned long fd, const struct compat_iovec __user *vec, - unsigned long vlen, u32 pos_high, u32 pos_low) + unsigned long vlen, u32 pos_low, u32 pos_high) { loff_t pos = ((loff_t)pos_high << 32) | pos_low; struct file *file; -- cgit v1.2.3-70-g09d2 From 0112fc2229847feb6c4eb011e6833d8f1742a375 Mon Sep 17 00:00:00 2001 From: Oleg Drokin Date: Wed, 8 Apr 2009 20:05:42 +0400 Subject: Separate out common fstatat code into vfs_fstatat This is a version incorporating Christoph's suggestion. Separate out common *fstatat functionality into a single function instead of duplicating it all over the code. Signed-off-by: Oleg Drokin Signed-off-by: Al Viro --- arch/arm/kernel/sys_oabi-compat.c | 19 ++++--------- arch/s390/kernel/compat_linux.c | 18 ++++--------- arch/sparc/kernel/sys_sparc32.c | 19 ++++--------- arch/x86/ia32/sys_ia32.c | 19 ++++--------- fs/compat.c | 19 ++++--------- fs/stat.c | 56 +++++++++++++++++++-------------------- include/linux/fs.h | 1 + 7 files changed, 54 insertions(+), 97 deletions(-) (limited to 'fs/compat.c') diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c index e04173c7e62..d59a0cd537f 100644 --- a/arch/arm/kernel/sys_oabi-compat.c +++ b/arch/arm/kernel/sys_oabi-compat.c @@ -177,21 +177,12 @@ asmlinkage long sys_oabi_fstatat64(int dfd, int flag) { struct kstat stat; - int error = -EINVAL; + int error; - if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) - goto out; - - if (flag & AT_SYMLINK_NOFOLLOW) - error = vfs_lstat_fd(dfd, filename, &stat); - else - error = vfs_stat_fd(dfd, filename, &stat); - - if (!error) - error = cp_oldabi_stat64(&stat, statbuf); - -out: - return error; + error = vfs_fstatat(dfd, filename, &stat, flag); + if (error) + return error; + return cp_oldabi_stat64(&stat, statbuf); } struct oabi_flock64 { diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c index 6cc87d8c868..002c70d3cb7 100644 --- a/arch/s390/kernel/compat_linux.c +++ b/arch/s390/kernel/compat_linux.c @@ -702,20 +702,12 @@ asmlinkage long sys32_fstatat64(unsigned int dfd, char __user *filename, struct stat64_emu31 __user* statbuf, int flag) { struct kstat stat; - int error = -EINVAL; - - if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) - goto out; - - if (flag & AT_SYMLINK_NOFOLLOW) - error = vfs_lstat_fd(dfd, filename, &stat); - else - error = vfs_stat_fd(dfd, filename, &stat); + int error; - if (!error) - error = cp_stat64(statbuf, &stat); -out: - return error; + error = vfs_fstatat(dfd, filename, &stat, flag); + if (error) + return error; + return cp_stat64(statbuf, &stat); } /* diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c index e800503879e..f5000a460c0 100644 --- a/arch/sparc/kernel/sys_sparc32.c +++ b/arch/sparc/kernel/sys_sparc32.c @@ -206,21 +206,12 @@ asmlinkage long compat_sys_fstatat64(unsigned int dfd, char __user *filename, struct compat_stat64 __user * statbuf, int flag) { struct kstat stat; - int error = -EINVAL; - - if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) - goto out; - - if (flag & AT_SYMLINK_NOFOLLOW) - error = vfs_lstat_fd(dfd, filename, &stat); - else - error = vfs_stat_fd(dfd, filename, &stat); - - if (!error) - error = cp_compat_stat64(&stat, statbuf); + int error; -out: - return error; + error = vfs_fstatat(dfd, filename, &stat, flag); + if (error) + return error; + return cp_compat_stat64(&stat, statbuf); } asmlinkage long compat_sys_sysfs(int option, u32 arg1, u32 arg2) diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c index efac92fd1ef..085a8c35f14 100644 --- a/arch/x86/ia32/sys_ia32.c +++ b/arch/x86/ia32/sys_ia32.c @@ -129,21 +129,12 @@ asmlinkage long sys32_fstatat(unsigned int dfd, char __user *filename, struct stat64 __user *statbuf, int flag) { struct kstat stat; - int error = -EINVAL; + int error; - if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) - goto out; - - if (flag & AT_SYMLINK_NOFOLLOW) - error = vfs_lstat_fd(dfd, filename, &stat); - else - error = vfs_stat_fd(dfd, filename, &stat); - - if (!error) - error = cp_stat64(statbuf, &stat); - -out: - return error; + error = vfs_fstatat(dfd, filename, &stat, flag); + if (error) + return error; + return cp_stat64(statbuf, &stat); } /* diff --git a/fs/compat.c b/fs/compat.c index 3f84d5f1588..dda72e26709 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -204,21 +204,12 @@ asmlinkage long compat_sys_newfstatat(unsigned int dfd, char __user *filename, struct compat_stat __user *statbuf, int flag) { struct kstat stat; - int error = -EINVAL; - - if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) - goto out; - - if (flag & AT_SYMLINK_NOFOLLOW) - error = vfs_lstat_fd(dfd, filename, &stat); - else - error = vfs_stat_fd(dfd, filename, &stat); - - if (!error) - error = cp_compat_stat(&stat, statbuf); + int error; -out: - return error; + error = vfs_fstatat(dfd, filename, &stat, flag); + if (error) + return error; + return cp_compat_stat(&stat, statbuf); } #endif diff --git a/fs/stat.c b/fs/stat.c index 2db740a0cfb..54711662b85 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -109,6 +109,24 @@ int vfs_fstat(unsigned int fd, struct kstat *stat) EXPORT_SYMBOL(vfs_fstat); +int vfs_fstatat(int dfd, char __user *filename, struct kstat *stat, int flag) +{ + int error = -EINVAL; + + if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) + goto out; + + if (flag & AT_SYMLINK_NOFOLLOW) + error = vfs_lstat_fd(dfd, filename, stat); + else + error = vfs_stat_fd(dfd, filename, stat); +out: + return error; +} + +EXPORT_SYMBOL(vfs_fstatat); + + #ifdef __ARCH_WANT_OLD_STAT /* @@ -264,21 +282,12 @@ SYSCALL_DEFINE4(newfstatat, int, dfd, char __user *, filename, struct stat __user *, statbuf, int, flag) { struct kstat stat; - int error = -EINVAL; - - if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) - goto out; - - if (flag & AT_SYMLINK_NOFOLLOW) - error = vfs_lstat_fd(dfd, filename, &stat); - else - error = vfs_stat_fd(dfd, filename, &stat); - - if (!error) - error = cp_new_stat(&stat, statbuf); + int error; -out: - return error; + error = vfs_fstatat(dfd, filename, &stat, flag); + if (error) + return error; + return cp_new_stat(&stat, statbuf); } #endif @@ -404,21 +413,12 @@ SYSCALL_DEFINE4(fstatat64, int, dfd, char __user *, filename, struct stat64 __user *, statbuf, int, flag) { struct kstat stat; - int error = -EINVAL; - - if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) - goto out; - - if (flag & AT_SYMLINK_NOFOLLOW) - error = vfs_lstat_fd(dfd, filename, &stat); - else - error = vfs_stat_fd(dfd, filename, &stat); - - if (!error) - error = cp_new_stat64(&stat, statbuf); + int error; -out: - return error; + error = vfs_fstatat(dfd, filename, &stat, flag); + if (error) + return error; + return cp_new_stat64(&stat, statbuf); } #endif /* __ARCH_WANT_STAT64 */ diff --git a/include/linux/fs.h b/include/linux/fs.h index e766be0d432..257f4d37ad2 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2302,6 +2302,7 @@ extern int vfs_lstat(char __user *, struct kstat *); extern int vfs_stat_fd(int dfd, char __user *, struct kstat *); extern int vfs_lstat_fd(int dfd, char __user *, struct kstat *); extern int vfs_fstat(unsigned int, struct kstat *); +extern int vfs_fstatat(int , char __user *, struct kstat *, int); extern int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, unsigned long arg); -- cgit v1.2.3-70-g09d2 From 2eae7a1874ca5be3232765d89e0250a449f1bc90 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 8 Apr 2009 16:34:03 -0400 Subject: kill vfs_stat_fd / vfs_lstat_fd There's really no reason to keep vfs_stat_fd and vfs_lstat_fd with Oleg's vfs_fstatat. Use vfs_fstatat for the few cases having the directory fd, and switch all others to vfs_stat / vfs_lstat. Reviewed-by: Christoph Hellwig Signed-off-by: Al Viro --- fs/compat.c | 18 +++++---- fs/stat.c | 105 +++++++++++++++++++++-------------------------------- include/linux/fs.h | 2 - 3 files changed, 52 insertions(+), 73 deletions(-) (limited to 'fs/compat.c') diff --git a/fs/compat.c b/fs/compat.c index dda72e26709..379a399bf5c 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -181,22 +181,24 @@ asmlinkage long compat_sys_newstat(char __user * filename, struct compat_stat __user *statbuf) { struct kstat stat; - int error = vfs_stat_fd(AT_FDCWD, filename, &stat); + int error; - if (!error) - error = cp_compat_stat(&stat, statbuf); - return error; + error = vfs_stat(filename, &stat); + if (error) + return error; + return cp_compat_stat(&stat, statbuf); } asmlinkage long compat_sys_newlstat(char __user * filename, struct compat_stat __user *statbuf) { struct kstat stat; - int error = vfs_lstat_fd(AT_FDCWD, filename, &stat); + int error; - if (!error) - error = cp_compat_stat(&stat, statbuf); - return error; + error = vfs_lstat(filename, &stat); + if (error) + return error; + return cp_compat_stat(&stat, statbuf); } #ifndef __ARCH_WANT_STAT64 diff --git a/fs/stat.c b/fs/stat.c index 54711662b85..075694e31d8 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -55,46 +55,6 @@ int vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) EXPORT_SYMBOL(vfs_getattr); -int vfs_stat_fd(int dfd, char __user *name, struct kstat *stat) -{ - struct path path; - int error; - - error = user_path_at(dfd, name, LOOKUP_FOLLOW, &path); - if (!error) { - error = vfs_getattr(path.mnt, path.dentry, stat); - path_put(&path); - } - return error; -} - -int vfs_stat(char __user *name, struct kstat *stat) -{ - return vfs_stat_fd(AT_FDCWD, name, stat); -} - -EXPORT_SYMBOL(vfs_stat); - -int vfs_lstat_fd(int dfd, char __user *name, struct kstat *stat) -{ - struct path path; - int error; - - error = user_path_at(dfd, name, 0, &path); - if (!error) { - error = vfs_getattr(path.mnt, path.dentry, stat); - path_put(&path); - } - return error; -} - -int vfs_lstat(char __user *name, struct kstat *stat) -{ - return vfs_lstat_fd(AT_FDCWD, name, stat); -} - -EXPORT_SYMBOL(vfs_lstat); - int vfs_fstat(unsigned int fd, struct kstat *stat) { struct file *f = fget(fd); @@ -106,26 +66,43 @@ int vfs_fstat(unsigned int fd, struct kstat *stat) } return error; } - EXPORT_SYMBOL(vfs_fstat); int vfs_fstatat(int dfd, char __user *filename, struct kstat *stat, int flag) { + struct path path; int error = -EINVAL; + int lookup_flags = 0; if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) goto out; - if (flag & AT_SYMLINK_NOFOLLOW) - error = vfs_lstat_fd(dfd, filename, stat); - else - error = vfs_stat_fd(dfd, filename, stat); + if (!(flag & AT_SYMLINK_NOFOLLOW)) + lookup_flags |= LOOKUP_FOLLOW; + + error = user_path_at(dfd, filename, lookup_flags, &path); + if (error) + goto out; + + error = vfs_getattr(path.mnt, path.dentry, stat); + path_put(&path); out: return error; } - EXPORT_SYMBOL(vfs_fstatat); +int vfs_stat(char __user *name, struct kstat *stat) +{ + return vfs_fstatat(AT_FDCWD, name, stat, 0); +} +EXPORT_SYMBOL(vfs_stat); + +int vfs_lstat(char __user *name, struct kstat *stat) +{ + return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW); +} +EXPORT_SYMBOL(vfs_lstat); + #ifdef __ARCH_WANT_OLD_STAT @@ -173,23 +150,25 @@ static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * sta SYSCALL_DEFINE2(stat, char __user *, filename, struct __old_kernel_stat __user *, statbuf) { struct kstat stat; - int error = vfs_stat_fd(AT_FDCWD, filename, &stat); + int error; - if (!error) - error = cp_old_stat(&stat, statbuf); + error = vfs_stat(filename, &stat); + if (error) + return error; - return error; + return cp_old_stat(&stat, statbuf); } SYSCALL_DEFINE2(lstat, char __user *, filename, struct __old_kernel_stat __user *, statbuf) { struct kstat stat; - int error = vfs_lstat_fd(AT_FDCWD, filename, &stat); + int error; - if (!error) - error = cp_old_stat(&stat, statbuf); + error = vfs_lstat(filename, &stat); + if (error) + return error; - return error; + return cp_old_stat(&stat, statbuf); } SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf) @@ -258,23 +237,23 @@ static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) SYSCALL_DEFINE2(newstat, char __user *, filename, struct stat __user *, statbuf) { struct kstat stat; - int error = vfs_stat_fd(AT_FDCWD, filename, &stat); - - if (!error) - error = cp_new_stat(&stat, statbuf); + int error = vfs_stat(filename, &stat); - return error; + if (error) + return error; + return cp_new_stat(&stat, statbuf); } SYSCALL_DEFINE2(newlstat, char __user *, filename, struct stat __user *, statbuf) { struct kstat stat; - int error = vfs_lstat_fd(AT_FDCWD, filename, &stat); + int error; - if (!error) - error = cp_new_stat(&stat, statbuf); + error = vfs_lstat(filename, &stat); + if (error) + return error; - return error; + return cp_new_stat(&stat, statbuf); } #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT) diff --git a/include/linux/fs.h b/include/linux/fs.h index 257f4d37ad2..8f42b35a756 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2299,8 +2299,6 @@ extern int vfs_readdir(struct file *, filldir_t, void *); extern int vfs_stat(char __user *, struct kstat *); extern int vfs_lstat(char __user *, struct kstat *); -extern int vfs_stat_fd(int dfd, char __user *, struct kstat *); -extern int vfs_lstat_fd(int dfd, char __user *, struct kstat *); extern int vfs_fstat(unsigned int, struct kstat *); extern int vfs_fstatat(int , char __user *, struct kstat *, int); -- cgit v1.2.3-70-g09d2 From 8c652f96d3852b97a49c331cd0bb02d22f3cb31b Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 24 Apr 2009 01:01:56 +0200 Subject: do_execve() must not clear fs->in_exec if it was set by another thread If do_execve() fails after check_unsafe_exec(), it clears fs->in_exec unconditionally. This is wrong if we race with our sub-thread which also does do_execve: Two threads T1 and T2 and another process P, all share the same ->fs. T1 starts do_execve(BAD_FILE). It calls check_unsafe_exec(), since ->fs is shared, we set LSM_UNSAFE but not ->in_exec. P exits and decrements fs->users. T2 starts do_execve(), calls check_unsafe_exec(), now ->fs is not shared, we set fs->in_exec. T1 continues, open_exec(BAD_FILE) fails, we clear ->in_exec and return to the user-space. T1 does clone(CLONE_FS /* without CLONE_THREAD */). T2 continues without LSM_UNSAFE_SHARE while ->fs is shared with another process. Change check_unsafe_exec() to return res = 1 if we set ->in_exec, and change do_execve() to clear ->in_exec depending on res. When do_execve() suceeds, it is safe to clear ->in_exec unconditionally. It can be set only if we don't share ->fs with another process, and since we already killed all sub-threads either ->in_exec == 0 or we are the only user of this ->fs. Also, we do not need fs->lock to clear fs->in_exec. Signed-off-by: Oleg Nesterov Acked-by: Roland McGrath Acked-by: Hugh Dickins Signed-off-by: Linus Torvalds --- fs/compat.c | 11 +++++------ fs/exec.c | 19 ++++++++++--------- 2 files changed, 15 insertions(+), 15 deletions(-) (limited to 'fs/compat.c') diff --git a/fs/compat.c b/fs/compat.c index 379a399bf5c..681ed81e6be 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -1476,6 +1476,7 @@ int compat_do_execve(char * filename, struct linux_binprm *bprm; struct file *file; struct files_struct *displaced; + bool clear_in_exec; int retval; retval = unshare_files(&displaced); @@ -1498,8 +1499,9 @@ int compat_do_execve(char * filename, goto out_unlock; retval = check_unsafe_exec(bprm); - if (retval) + if (retval < 0) goto out_unlock; + clear_in_exec = retval; file = open_exec(filename); retval = PTR_ERR(file); @@ -1546,9 +1548,7 @@ int compat_do_execve(char * filename, goto out; /* execve succeeded */ - write_lock(¤t->fs->lock); current->fs->in_exec = 0; - write_unlock(¤t->fs->lock); current->in_execve = 0; mutex_unlock(¤t->cred_exec_mutex); acct_update_integrals(current); @@ -1568,9 +1568,8 @@ out_file: } out_unmark: - write_lock(¤t->fs->lock); - current->fs->in_exec = 0; - write_unlock(¤t->fs->lock); + if (clear_in_exec) + current->fs->in_exec = 0; out_unlock: current->in_execve = 0; diff --git a/fs/exec.c b/fs/exec.c index 052a961e41a..a2e6989dbc3 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1077,9 +1077,11 @@ int check_unsafe_exec(struct linux_binprm *bprm) if (p->fs->users > n_fs) { bprm->unsafe |= LSM_UNSAFE_SHARE; } else { - if (p->fs->in_exec) - res = -EAGAIN; - p->fs->in_exec = 1; + res = -EAGAIN; + if (!p->fs->in_exec) { + p->fs->in_exec = 1; + res = 1; + } } unlock_task_sighand(p, &flags); @@ -1284,6 +1286,7 @@ int do_execve(char * filename, struct linux_binprm *bprm; struct file *file; struct files_struct *displaced; + bool clear_in_exec; int retval; retval = unshare_files(&displaced); @@ -1306,8 +1309,9 @@ int do_execve(char * filename, goto out_unlock; retval = check_unsafe_exec(bprm); - if (retval) + if (retval < 0) goto out_unlock; + clear_in_exec = retval; file = open_exec(filename); retval = PTR_ERR(file); @@ -1355,9 +1359,7 @@ int do_execve(char * filename, goto out; /* execve succeeded */ - write_lock(¤t->fs->lock); current->fs->in_exec = 0; - write_unlock(¤t->fs->lock); current->in_execve = 0; mutex_unlock(¤t->cred_exec_mutex); acct_update_integrals(current); @@ -1377,9 +1379,8 @@ out_file: } out_unmark: - write_lock(¤t->fs->lock); - current->fs->in_exec = 0; - write_unlock(¤t->fs->lock); + if (clear_in_exec) + current->fs->in_exec = 0; out_unlock: current->in_execve = 0; -- cgit v1.2.3-70-g09d2