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* exec: unify do_execve/compat_do_execve codeOleg Nesterov2011-04-09
| | | | | | | | | | | | | | | | | | | | Add the appropriate members into struct user_arg_ptr and teach get_user_arg_ptr() to handle is_compat = T case correctly. This allows us to remove the compat_do_execve() code from fs/compat.c and reimplement compat_do_execve() as the trivial wrapper on top of do_execve_common(is_compat => true). In fact, this fixes another (minor) bug. "compat_uptr_t str" can overflow after "str += len" in compat_copy_strings() if a 64bit application execs via sys32_execve(). Unexport acct_arg_size() and get_arg_page(), fs/compat.c doesn't need them any longer. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
* select: remove unused MAX_SELECT_SECONDSNamhyung Kim2011-03-21
| | | | | | | | | Remove the leftover from the commit 8ff3e8e85fa6 ("select: switch select() and poll() over to hrtimers"). Signed-off-by: Namhyung Kim <namhyung@gmail.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* vfs: Add open by file handle supportAneesh Kumar K.V2011-03-15
| | | | | | | [AV: duplicate of open() guts removed; file_open_root() used instead] Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* clean statfs-like syscalls upAl Viro2011-03-14
| | | | | | | | | | New helpers: user_statfs() and fd_statfs(), taking userland pathname and descriptor resp. and filling struct kstatfs. Syscalls of statfs family (native, compat and foreign - osf and hpux on alpha and parisc resp.) switched to those. Removes some boilerplate code, simplifies cleanup on errors... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* compat breakage in preadv() and pwritev()Al Viro2011-03-13
| | | | | | | | | | Fix for a dumb preadv()/pwritev() compat bug - unlike the native variants, compat_... ones forget to check FMODE_P{READ,WRITE}, so e.g. on pipe the native preadv() will fail with -ESPIPE and compat one will act as readv() and succeed. Not critical, but it's a clear bug with trivial fix. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* compat: copy missing fields in compat_statfs64 to userNamhyung Kim2011-01-17
| | | | | | | | | f_flags and f_spare fields were not copied to userspace when compat_sys_[f]statfs64 called. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* compat: update comment of compat statfs syscallsNamhyung Kim2011-01-17
| | | | | | | | | | The commit 7ed1ee6118ae ("Take statfs variants to fs/statfs.c") separates out statfs syscalls from fs/open.c. Thus the comment should be changed also. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Cc: Jiri Kosina <trivial@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* compat: remove unnecessary assignment in compat_rw_copy_check_uvector()Namhyung Kim2011-01-17
| | | | | | | | | *@ret_pointer is initialized to @fast_pointer thus the assignment is redundant. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Cc: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* exec: copy-and-paste the fixes into compat_do_execve() pathsOleg Nesterov2010-11-30
| | | | | | | | | | | | | | | | | | | | | | | Note: this patch targets 2.6.37 and tries to be as simple as possible. That is why it adds more copy-and-paste horror into fs/compat.c and uglifies fs/exec.c, this will be cleanuped later. compat_copy_strings() plays with bprm->vma/mm directly and thus has two problems: it lacks the RLIMIT_STACK check and argv/envp memory is not visible to oom killer. Export acct_arg_size() and get_arg_page(), change compat_copy_strings() to use get_arg_page(), change compat_do_execve() to do acct_arg_size(0) as do_execve() does. Add the fatal_signal_pending/cond_resched checks into compat_count() and compat_copy_strings(), this matches the code in fs/exec.c and certainly makes sense. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/compat.c: fix build on MIPS/s390wu zhangjin2010-10-30
| | | | | | | | | | | | | | The definition of PAGE_CACHE_MASK in <linux/pagemap.h> is needed to use MAX_RW_COUNT, and on x86-64 that gets done indirectly through the architecture header includes. But on MIPS and s390 that doesn't happen, and we need to make sure that fs/compat.c includes pagemap.h explicitly. Introduced in commit 435f49a518c7 ("readv/writev: do the same MAX_RW_COUNT truncation that read/write does"). Reported-by: Sachin Sant <sachinp@in.ibm.com> (S390) Reported-by: wu zhangjin <wuzhangjin@gmail.com> (MIPS) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* readv/writev: do the same MAX_RW_COUNT truncation that read/write doesLinus Torvalds2010-10-29
| | | | | | | | | | We used to protect against overflow, but rather than return an error, do what read/write does, namely to limit the total size to MAX_RW_COUNT. This is not only more consistent, but it also means that any broken low-level read/write routine that still keeps counts in 'int' can't break. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge 'staging-next' to Linus's treeGreg Kroah-Hartman2010-10-28
|\ | | | | | | | | | | | | | | This merges the staging-next tree to Linus's tree and resolves some conflicts that were present due to changes in other trees that were affected by files here. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * smbfs: move to drivers/stagingArnd Bergmann2010-10-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | smbfs has been scheduled for removal in 2.6.27, so maybe we can now move it to drivers/staging on the way out. smbfs still uses the big kernel lock and nobody is going to fix that, so we should be getting rid of it soon. This removes the 32 bit compat mount and ioctl handling code, which is implemented in common fs code, and moves all smbfs related files into drivers/staging/smbfs. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | Merge branch 'for-2.6.37' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2010-10-26
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-2.6.37' of git://linux-nfs.org/~bfields/linux: (99 commits) svcrpc: svc_tcp_sendto XPT_DEAD check is redundant svcrpc: no need for XPT_DEAD check in svc_xprt_enqueue svcrpc: assume svc_delete_xprt() called only once svcrpc: never clear XPT_BUSY on dead xprt nfsd4: fix connection allocation in sequence() nfsd4: only require krb5 principal for NFSv4.0 callbacks nfsd4: move minorversion to client nfsd4: delay session removal till free_client nfsd4: separate callback change and callback probe nfsd4: callback program number is per-session nfsd4: track backchannel connections nfsd4: confirm only on succesful create_session nfsd4: make backchannel sequence number per-session nfsd4: use client pointer to backchannel session nfsd4: move callback setup into session init code nfsd4: don't cache seq_misordered replies SUNRPC: Properly initialize sock_xprt.srcaddr in all cases SUNRPC: Use conventional switch statement when reclassifying sockets sunrpc/xprtrdma: clean up workqueue usage sunrpc: Turn list_for_each-s into the ..._entry-s ... Fix up trivial conflicts (two different deprecation notices added in separate branches) in Documentation/feature-removal-schedule.txt
| * | nfsd: allow deprecated interface to be compiled out.NeilBrown2010-09-22
| |/ | | | | | | | | | | | | | | | | | | Add CONFIG_NFSD_DEPRECATED, default to y. Only include deprecated interface if this is defined. This allows distros to remove this interface before the official removal, and allows developers to test without it. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* / Prevent freeing uninitialized pointer in compat_do_readv_writevDan Rosenberg2010-09-22
|/ | | | | | | | | | | | | | | | | In 32-bit compatibility mode, the error handling for compat_do_readv_writev() may free an uninitialized pointer, potentially leading to all sorts of ugly memory corruption. This is reliably triggerable by unprivileged users by invoking the readv()/writev() syscalls with an invalid iovec pointer. The below patch fixes this to emulate the non-compat version. Introduced by commit b83733639a49 ("compat: factor out compat_rw_copy_check_uvector from compat_do_readv_writev") Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com> Cc: stable@kernel.org (2.6.35) Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Mark arguments to certain syscalls as being constDavid Howells2010-08-13
| | | | | | | | | | | | | | | | Mark arguments to certain system calls as being const where they should be but aren't. The list includes: (*) The filename arguments of various stat syscalls, execve(), various utimes syscalls and some mount syscalls. (*) The filename arguments of some syscall helpers relating to the above. (*) The buffer argument of various write syscalls. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notifyLinus Torvalds2010-08-10
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.infradead.org/users/eparis/notify: (132 commits) fanotify: use both marks when possible fsnotify: pass both the vfsmount mark and inode mark fsnotify: walk the inode and vfsmount lists simultaneously fsnotify: rework ignored mark flushing fsnotify: remove global fsnotify groups lists fsnotify: remove group->mask fsnotify: remove the global masks fsnotify: cleanup should_send_event fanotify: use the mark in handler functions audit: use the mark in handler functions dnotify: use the mark in handler functions inotify: use the mark in handler functions fsnotify: send fsnotify_mark to groups in event handling functions fsnotify: Exchange list heads instead of moving elements fsnotify: srcu to protect read side of inode and vfsmount locks fsnotify: use an explicit flag to indicate fsnotify_destroy_mark has been called fsnotify: use _rcu functions for mark list traversal fsnotify: place marks on object in order of group memory address vfs/fsnotify: fsnotify_close can delay the final work in fput fsnotify: store struct file not struct path ... Fix up trivial delete/modify conflict in fs/notify/inotify/inotify.c.
| * fsnotify: pass a file instead of an inode to open, read, and writeEric Paris2010-07-28
| | | | | | | | | | | | | | | | | | | | fanotify, the upcoming notification system actually needs a struct path so it can do opens in the context of listeners, and it needs a file so it can get f_flags from the original process. Close was the only operation that already was passing a struct file to the notification hook. This patch passes a file for access, modify, and open as well as they are easily available to these hooks. Signed-off-by: Eric Paris <eparis@redhat.com>
* | Merge branch 'for-linus' of ↵Linus Torvalds2010-08-10
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (96 commits) no need for list_for_each_entry_safe()/resetting with superblock list Fix sget() race with failing mount vfs: don't hold s_umount over close_bdev_exclusive() call sysv: do not mark superblock dirty on remount sysv: do not mark superblock dirty on mount btrfs: remove junk sb_dirt change BFS: clean up the superblock usage AFFS: wait for sb synchronization when needed AFFS: clean up dirty flag usage cifs: truncate fallout mbcache: fix shrinker function return value mbcache: Remove unused features add f_flags to struct statfs(64) pass a struct path to vfs_statfs update VFS documentation for method changes. All filesystems that need invalidate_inode_buffers() are doing that explicitly convert remaining ->clear_inode() to ->evict_inode() Make ->drop_inode() just return whether inode needs to be dropped fs/inode.c:clear_inode() is gone fs/inode.c:evict() doesn't care about delete vs. non-delete paths now ... Fix up trivial conflicts in fs/nilfs2/super.c
| * | pass a struct path to vfs_statfsChristoph Hellwig2010-08-09
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We'll need the path to implement the flags field for statvfs support. We do have it available in all callers except: - ecryptfs_statfs. This one doesn't actually need vfs_statfs but just needs to do a caller to the lower filesystem statfs method. - sys_ustat. Add a non-exported statfs_by_dentry helper for it which doesn't won't be able to fill out the flags field later on. In addition rename the helpers for statfs vs fstatfs to do_*statfs instead of the misleading vfs prefix. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | vfs: fix warning: 'dirent' is used uninitialized in this functionKevin Winchester2010-08-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using: gcc (GCC) 4.5.0 20100610 (prerelease) The following warnings appear: fs/readdir.c: In function `filldir64': fs/readdir.c:240:15: warning: `dirent' is used uninitialized in this function fs/readdir.c: In function `filldir': fs/readdir.c:155:15: warning: `dirent' is used uninitialized in this function fs/compat.c: In function `compat_filldir64': fs/compat.c:1071:11: warning: `dirent' is used uninitialized in this function fs/compat.c: In function `compat_filldir': fs/compat.c:984:15: warning: `dirent' is used uninitialized in this function The warnings are related to the use of the NAME_OFFSET() macro. Luckily, it appears as though the standard offsetof() macro is what is being implemented by NAME_OFFSET(), thus we can fix the warning and use a more standard code construct at the same time. Signed-off-by: Kevin Winchester <kjwinchester@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | update email addressPavel Machek2010-07-19
|/ | | | | | | pavel@suse.cz no longer works, replace it with working address. Signed-off-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* fs/compat_rw_copy_check_uvector: add missing compat_ptr callHeiko Carstens2010-06-04
| | | | | | | | | | | | | | | A call to access_ok is missing a compat_ptr conversion. Introduced with b83733639a494d5f42fa00a2506563fbd2d3015d "compat: factor out compat_rw_copy_check_uvector from compat_do_readv_writev" fs/compat.c: In function 'compat_rw_copy_check_uvector': fs/compat.c:629: warning: passing argument 1 of '__access_ok' makes pointer from integer without a cast Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* aio: fix the compat vectored operationsJeff Moyer2010-05-27
| | | | | | | | | | | | | | | | | | | | | | | | The aio compat code was not converting the struct iovecs from 32bit to 64bit pointers, causing either EINVAL to be returned from io_getevents, or EFAULT as the result of the I/O. This patch passes a compat flag to io_submit to signal that pointer conversion is necessary for a given iocb array. A variant of this was tested by Michael Tokarev. I have also updated the libaio test harness to exercise this code path with good success. Further, I grabbed a copy of ltp and ran the testcases/kernel/syscall/readv and writev tests there (compiled with -m32 on my 64bit system). All seems happy, but extra eyes on this would be welcome. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix CONFIG_COMPAT=n build] Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Reported-by: Michael Tokarev <mjt@tls.msk.ru> Cc: Zach Brown <zach.brown@oracle.com> Cc: <stable@kernel.org> [2.6.35.1] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* compat: factor out compat_rw_copy_check_uvector from compat_do_readv_writevJeff Moyer2010-05-27
| | | | | | | | | | | | | | | | | | | | | | | It was reported in http://lkml.org/lkml/2010/3/8/309 that 32 bit readv and writev AIO operations were not functioning properly. It turns out that the code to convert the 32bit io vectors to 64 bits was never written. The results of that can be pretty bad, but in my testing, it mostly ended up in generating EFAULT as we walked off the list of I/O vectors provided. This patch set fixes the problem in my environment. are greatly appreciated. This patch: Factor out code that will be used by both compat_do_readv_writev and the compat aio submission code paths. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Reported-by: Michael Tokarev <mjt@tls.msk.ru> Cc: Zach Brown <zach.brown@oracle.com> Cc: <stable@kernel.org> [2.6.35.1] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* revert "procfs: provide stack information for threads" and its fixup commitsRobin Holt2010-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Originally, commit d899bf7b ("procfs: provide stack information for threads") attempted to introduce a new feature for showing where the threadstack was located and how many pages are being utilized by the stack. Commit c44972f1 ("procfs: disable per-task stack usage on NOMMU") was applied to fix the NO_MMU case. Commit 89240ba0 ("x86, fs: Fix x86 procfs stack information for threads on 64-bit") was applied to fix a bug in ia32 executables being loaded. Commit 9ebd4eba7 ("procfs: fix /proc/<pid>/stat stack pointer for kernel threads") was applied to fix a bug which had kernel threads printing a userland stack address. Commit 1306d603f ('proc: partially revert "procfs: provide stack information for threads"') was then applied to revert the stack pages being used to solve a significant performance regression. This patch nearly undoes the effect of all these patches. The reason for reverting these is it provides an unusable value in field 28. For x86_64, a fork will result in the task->stack_start value being updated to the current user top of stack and not the stack start address. This unpredictability of the stack_start value makes it worthless. That includes the intended use of showing how much stack space a thread has. Other architectures will get different values. As an example, ia64 gets 0. The do_fork() and copy_process() functions appear to treat the stack_start and stack_size parameters as architecture specific. I only partially reverted c44972f1 ("procfs: disable per-task stack usage on NOMMU") . If I had completely reverted it, I would have had to change mm/Makefile only build pagewalk.o when CONFIG_PROC_PAGE_MONITOR is configured. Since I could not test the builds without significant effort, I decided to not change mm/Makefile. I only partially reverted 89240ba0 ("x86, fs: Fix x86 procfs stack information for threads on 64-bit") . I left the KSTK_ESP() change in place as that seemed worthwhile. Signed-off-by: Robin Holt <holt@sgi.com> Cc: Stefani Seibold <stefani@seibold.net> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* Add generic sys_old_select()Christoph Hellwig2010-03-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a generic implementation of the old select() syscall, which expects its argument in a memory block and switch all architectures over to use it. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: James Morris <jmorris@namei.org> Acked-by: Andreas Schwab <schwab@linux-m68k.org> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Greg Ungerer <gerg@uclinux.org> Acked-by: David Howells <dhowells@redhat.com> Cc: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* compat.c: Remove dependence on nfsd private headersBoaz Harrosh2009-12-14
| | | | | | | | | | | | | Two nfsd related headers where included but never actually used. The linux/nfsd/nfsd.h file will eventually be moved to fs/nfsd directory as it is only needed by nfsd itself. There are 3 more compat.c files in the Kernel at other ARCHs that wrongly #include nfsd headers. Once these are fixed the headers can be moved. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* x86, fs: Fix x86 procfs stack information for threads on 64-bitStefani Seibold2009-11-04
| | | | | | | | | | | | | | | | | | | | | | This patch fixes two issues in the procfs stack information on x86-64 linux. The 32 bit loader compat_do_execve did not store stack start. (this was figured out by Alexey Dobriyan). The stack information on a x64_64 kernel always shows 0 kbyte stack usage, because of a missing implementation of the KSTK_ESP macro which always returned -1. The new implementation now returns the right value. Signed-off-by: Stefani Seibold <stefani@seibold.net> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1257240160.4889.24.camel@wall-e> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* fs: fix overflow in sys_mount() for in-kernel callsVegard Nossum2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | sys_mount() reads/copies a whole page for its "type" parameter. When do_mount_root() passes a kernel address that points to an object which is smaller than a whole page, copy_mount_options() will happily go past this memory object, possibly dereferencing "wild" pointers that could be in any state (hence the kmemcheck warning, which shows that parts of the next page are not even allocated). (The likelihood of something going wrong here is pretty low -- first of all this only applies to kernel calls to sys_mount(), which are mostly found in the boot code. Secondly, I guess if the page was not mapped, exact_copy_from_user() _would_ in fact handle it correctly because of its access_ok(), etc. checks.) But it is much nicer to avoid the dubious reads altogether, by stopping as soon as we find a NUL byte. Is there a good reason why we can't do something like this, using the already existing strndup_from_user()? [akpm@linux-foundation.org: make copy_mount_string() static] [AV: fix compat mount breakage, which involves undoing akpm's change above] Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: al <al@dizzy.pdmi.ras.ru>
* fix compat_sys_utimensat()Suzuki Poulose2009-09-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Compat utimensat() returns EINVAL when the tv_nsec is one of UTIME_OMIT or UTIME_NOW and the tv_sec is set to non-zero. As per man pages, the tv_sec field should be ignored. sys_utimensat() works fine in this case. Test case: #define _GNU_SOURCE #define _ATFILE_SOURCE #include <stdio.h> #include <fcntl.h> #include <unistd.h> #include <sys/stat.h> #include <stdlib.h> main(int argc, char *argv[]) { struct timespec ts[2]; struct timespec *tsp; if (argc < 2) { fprintf(stderr, "Usage : %s filename\n", argv[0]); exit (-1); } ts[0].tv_nsec = ts[1].tv_nsec = UTIME_NOW; ts[0].tv_sec = ts[1].tv_sec = 1; tsp = ts; if (utimensat(AT_FDCWD, argv[1],tsp,0) == -1) perror("utimensat"); else fprintf(stdout, "utimensat success\n"); return 0; } mjs22lp5:~ # cc -m64 utimensat-test.c -o utimensat_test64 mjs22lp5:~ # cc -m32 utimensat-test.c -o utimensat_test32 mjs22lp5:~ # ./utimensat_test32 /tmp/utimensat_test utimensat: Invalid argument mjs22lp5:~ # ./utimensat_test64 /tmp/utimensat_test utimensat success mjs22lp5:~ # uname -r 2.6.31-rc8 With the patch : mjs22lp5:~ # ./utimensat_test64 /tmp/utimensat_test utimensat success mjs22lp5:~ # ./utimensat_test32 /tmp/utimensat_test utimensat success mjs22lp5:~ # uname -r 2.6.31-rc8utimensat Signed-off-by: Suzuki K P <suzuki@in.ibm.com> Cc: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exec: do not sleep in TASK_TRACED under ->cred_guard_mutexOleg Nesterov2009-09-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tom Horsley reports that his debugger hangs when it tries to read /proc/pid_of_tracee/maps, this happens since "mm_for_maps: take ->cred_guard_mutex to fix the race with exec" 04b836cbf19e885f8366bccb2e4b0474346c02d commit in 2.6.31. But the root of the problem lies in the fact that do_execve() path calls tracehook_report_exec() which can stop if the tracer sets PT_TRACE_EXEC. The tracee must not sleep in TASK_TRACED holding this mutex. Even if we remove ->cred_guard_mutex from mm_for_maps() and proc_pid_attr_write(), another task doing PTRACE_ATTACH should not hang until it is killed or the tracee resumes. With this patch do_execve() does not use ->cred_guard_mutex directly and we do not hold it throughout, instead: - introduce prepare_bprm_creds() helper, it locks the mutex and calls prepare_exec_creds() to initialize bprm->cred. - install_exec_creds() drops the mutex after commit_creds(), and thus before tracehook_report_exec()->ptrace_stop(). or, if exec fails, free_bprm() drops this mutex when bprm->cred != NULL which indicates install_exec_creds() was not called. Reported-by: Tom Horsley <tom.horsley@att.net> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* headers: smp_lock.h reduxAlexey Dobriyan2009-07-12
| | | | | | | | | | | | | * Remove smp_lock.h from files which don't need it (including some headers!) * Add smp_lock.h to files which do need it * Make smp_lock.h include conditional in hardirq.h It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT This will make hardirq.h inclusion cheaper for every PREEMPT=n config (which includes allmodconfig/allyesconfig, BTW) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cred_guard_mutex: do not return -EINTR to user-spaceOleg Nesterov2009-07-06
| | | | | | | | | | | | | | | | do_execve() and ptrace_attach() return -EINTR if mutex_lock_interruptible(->cred_guard_mutex) fails. This is not right, change the code to return ERESTARTNOINTR. Perhaps we should also change proc_pid_attr_write(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: David Howells <dhowells@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* trivial: fix comment typo in fs/compat.cNikanth Karthikesan2009-06-12
| | | | | | | Fix a typo in fs/compat.c Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* Push BKL into do_mount()Al Viro2009-06-11
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* CRED: Rename cred_exec_mutex to reflect that it's a guard against ptraceDavid Howells2009-05-10
| | | | | | | | | | Rename cred_exec_mutex to reflect that it's a guard against foreign intervention on a process's credential state, such as is made by ptrace(). The attachment of a debugger to a process affects execve()'s calculation of the new credential state - _and_ also setprocattr()'s calculation of that state. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* do_execve() must not clear fs->in_exec if it was set by another threadOleg Nesterov2009-04-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kill vfs_stat_fd / vfs_lstat_fdChristoph Hellwig2009-04-20
| | | | | | | | | | 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 <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Separate out common fstatat code into vfs_fstatatOleg Drokin2009-04-20
| | | | | | | | | | 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 <green@linuxhacker.ru> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Make non-compat preadv/pwritev use native register sizeLinus Torvalds2009-04-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <kraxel@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: Ingo Molnar <mingo@elte.hu> Cc: Ralf Baechle <ralf@linux-mips.org>> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2009-04-03
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: Remove two unneeded exports and make two symbols static in fs/mpage.c Cleanup after commit 585d3bc06f4ca57f975a5a1f698f65a45ea66225 Trim includes of fdtable.h Don't crap into descriptor table in binfmt_som Trim includes in binfmt_elf Don't mess with descriptor table in load_elf_binary() Get rid of indirect include of fs_struct.h New helper - current_umask() check_unsafe_exec() doesn't care about signal handlers sharing New locking/refcounting for fs_struct Take fs_struct handling to new file (fs/fs_struct.c) Get rid of bumping fs_struct refcount in pivot_root(2) Kill unsharing fs_struct in __set_personality()
| * New locking/refcounting for fs_structAl Viro2009-03-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * all changes of current->fs are done under task_lock and write_lock of old fs->lock * refcount is not atomic anymore (same protection) * its decrements are done when removing reference from current; at the same time we decide whether to free it. * put_fs_struct() is gone * new field - ->in_exec. Set by check_unsafe_exec() if we are trying to do execve() and only subthreads share fs_struct. Cleared when finishing exec (success and failure alike). Makes CLONE_FS fail with -EAGAIN if set. * check_unsafe_exec() may fail with -EAGAIN if another execve() from subthread is in progress. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | preadv/pwritev: switch compat readv/preadv/writev/pwritev from fget to ↵Gerd Hoffmann2009-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | fget_light Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <linux-api@vger.kernel.org> Cc: <linux-arch@vger.kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | preadv/pwritev: Add preadv and pwritev system calls.Gerd Hoffmann2009-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds preadv and pwritev system calls. These syscalls are a pretty straightforward combination of pread and readv (same for write). They are quite useful for doing vectored I/O in threaded applications. Using lseek+readv instead opens race windows you'll have to plug with locking. Other systems have such system calls too, for example NetBSD, check here: http://www.daemon-systems.org/man/preadv.2.html The application-visible interface provided by glibc should look like this to be compatible to the existing implementations in the *BSD family: ssize_t preadv(int d, const struct iovec *iov, int iovcnt, off_t offset); ssize_t pwritev(int d, const struct iovec *iov, int iovcnt, off_t offset); This prototype has one problem though: On 32bit archs is the (64bit) offset argument unaligned, which the syscall ABI of several archs doesn't allow to do. At least s390 needs a wrapper in glibc to handle this. As we'll need a wrappers in glibc anyway I've decided to push problem to glibc entriely and use a syscall prototype which works without arch-specific wrappers inside the kernel: The offset argument is explicitly splitted into two 32bit values. The patch sports the actual system call implementation and the windup in the x86 system call tables. Other archs follow as separate patches. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <linux-api@vger.kernel.org> Cc: <linux-arch@vger.kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | preadv/pwritev: create compat_writev()Gerd Hoffmann2009-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Factor out some code from compat_sys_writev() which can be shared with the upcoming compat_sys_pwritev(). Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <linux-api@vger.kernel.org> Cc: <linux-arch@vger.kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | preadv/pwritev: create compat_readv()Gerd Hoffmann2009-04-02
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch series: Implement the preadv() and pwritev() syscalls. *BSD has this syscall for quite some time. Test code: #if 0 set -x gcc -Wall -O2 -o preadv $0 exit 0 #endif /* * preadv demo / test * * (c) 2008 Gerd Hoffmann <kraxel@redhat.com> * * build with "sh $thisfile" */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <errno.h> #include <inttypes.h> #include <sys/uio.h> /* ----------------------------------------------------------------- */ /* syscall windup */ #include <sys/syscall.h> #if 0 /* WARNING: Be sure you know what you are doing if you enable this. * linux syscall code isn't upstream yet, syscall numbers are subject * to change */ # ifndef __NR_preadv # ifdef __i386__ # define __NR_preadv 333 # define __NR_pwritev 334 # endif # ifdef __x86_64__ # define __NR_preadv 295 # define __NR_pwritev 296 # endif # endif #endif #ifndef __NR_preadv # error preadv/pwritev syscall numbers are unknown #endif static ssize_t preadv(int fd, const struct iovec *iov, int iovcnt, off_t offset) { uint32_t pos_high = (offset >> 32) & 0xffffffff; uint32_t pos_low = offset & 0xffffffff; return syscall(__NR_preadv, fd, iov, iovcnt, pos_high, pos_low); } static ssize_t pwritev(int fd, const struct iovec *iov, int iovcnt, off_t offset) { uint32_t pos_high = (offset >> 32) & 0xffffffff; uint32_t pos_low = offset & 0xffffffff; return syscall(__NR_pwritev, fd, iov, iovcnt, pos_high, pos_low); } /* ----------------------------------------------------------------- */ /* demo/test app */ static char filename[] = "/tmp/preadv-XXXXXX"; static char outbuf[11] = "0123456789"; static char inbuf[11] = "----------"; static struct iovec ovec[2] = {{ .iov_base = outbuf + 5, .iov_len = 5, },{ .iov_base = outbuf + 0, .iov_len = 5, }}; static struct iovec ivec[3] = {{ .iov_base = inbuf + 6, .iov_len = 2, },{ .iov_base = inbuf + 4, .iov_len = 2, },{ .iov_base = inbuf + 2, .iov_len = 2, }}; void cleanup(void) { unlink(filename); } int main(int argc, char **argv) { int fd, rc; fd = mkstemp(filename); if (-1 == fd) { perror("mkstemp"); exit(1); } atexit(cleanup); /* write to file: "56789-01234" */ rc = pwritev(fd, ovec, 2, 0); if (rc < 0) { perror("pwritev"); exit(1); } /* read from file: "78-90-12" */ rc = preadv(fd, ivec, 3, 2); if (rc < 0) { perror("preadv"); exit(1); } printf("result : %s\n", inbuf); printf("expected: %s\n", "--129078--"); exit(0); } This patch: Factor out some code from compat_sys_readv() which can be shared with the upcoming compat_sys_preadv(). Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <linux-api@vger.kernel.org> Cc: <linux-arch@vger.kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fix setuid sometimes doesn'tHugh Dickins2009-03-28
| | | | | | | | | | | | | | | | | | | | | | | | | | Joe Malicki reports that setuid sometimes doesn't: very rarely, a setuid root program does not get root euid; and, by the way, they have a health check running lsof every few minutes. Right, check_unsafe_exec() notes whether the files_struct is being shared by more threads than will get killed by the exec, and if so sets LSM_UNSAFE_SHARE to make bprm_set_creds() careful about euid. But /proc/<pid>/fd and /proc/<pid>/fdinfo lookups make transient use of get_files_struct(), which also raises that sharing count. There's a rather simple fix for this: exec's check on files->count has been redundant ever since 2.6.1 made it unshare_files() (except while compat_do_execve() omitted to do so) - just remove that check. [Note to -stable: this patch will not apply before 2.6.29: earlier releases should just remove the files->count line from unsafe_exec().] Reported-by: Joe Malicki <jmalicki@metacarta.com> Narrowed-down-by: Michael Itz <mitz@metacarta.com> Tested-by: Joe Malicki <jmalicki@metacarta.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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