linux/fs/proc, branch v2.6.34

revert "procfs: provide stack information for threads" and its fixup commits

2010-05-12T00:33:41Z

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//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 Cc: Stefani Seibold Cc: KOSAKI Motohiro Cc: Michal Simek Cc: Ingo Molnar Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

procfs: fix tid fdinfo

2010-04-27T23:26:03Z

Correct the file_operations struct in fdinfo entry of tid_base_stuff[]. Presently /proc/*/task/*/fdinfo contains symlinks to opened files like /proc/*/fd/. Signed-off-by: Jerome Marchand Cc: Alexander Viro Cc: Miklos Szeredi Cc: Alexey Dobriyan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pagemap: fix pfn calculation for hugepage

2010-04-07T15:38:04Z

When we look into pagemap using page-types with option -p, the value of pfn for hugepages looks wrong (see below.) This is because pte was evaluated only once for one vma although it should be updated for each hugepage. This patch fixes it. $ page-types -p 3277 -Nl -b huge voffset offset len flags 7f21e8a00 11e400 1 ___U___________H_G________________ 7f21e8a01 11e401 1ff ________________TG________________ ^^^ 7f21e8c00 11e400 1 ___U___________H_G________________ 7f21e8c01 11e401 1ff ________________TG________________ ^^^ One hugepage contains 1 head page and 511 tail pages in x86_64 and each two lines represent each hugepage. Voffset and offset mean virtual address and physical address in the page unit, respectively. The different hugepages should not have the same offset value. With this patch applied: $ page-types -p 3386 -Nl -b huge voffset offset len flags 7fec7a600 112c00 1 ___UD__________H_G________________ 7fec7a601 112c01 1ff ________________TG________________ ^^^ 7fec7a800 113200 1 ___UD__________H_G________________ 7fec7a801 113201 1ff ________________TG________________ ^^^ OK More info: - This patch modifies walk_page_range()'s hugepage walker. But the change only affects pagemap_read(), which is the only caller of hugepage callback. - Without this patch, hugetlb_entry() callback is called per vma, that doesn't match the natural expectation from its name. - With this patch, hugetlb_entry() is called per hugepte entry and the callback can become much simpler. Signed-off-by: Naoya Horiguchi Signed-off-by: KAMEZAWA Hiroyuki Acked-by: Matt Mackall Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

proc: copy_to_user() returns unsigned

2010-04-06T15:23:47Z

copy_to_user() returns the number of bytes left to be copied. This was a typo from: d82ef020cf31 "proc: pagemap: Hold mmap_sem during page walk". Signed-off-by: Dan Carpenter Acked-by: Matt Mackall Signed-off-by: Linus Torvalds

Merge branch 'master' into export-slabh

2010-04-05T02:37:28Z

proc: pagemap: Hold mmap_sem during page walk

2010-04-04T19:06:02Z

In initial design, walk_page_range() was designed just for walking page table and it didn't require mmap_sem. Now, find_vma() etc.. are used in walk_page_range() and we need mmap_sem around it. This patch adds mmap_sem around walk_page_range(). Because /proc//pagemap's callback routine use put_user(), we have to get rid of it to do sane fix. Changelog: 2010/Apr/2 - fixed start_vaddr and end overflow Changelog: 2010/Apr/1 - fixed start_vaddr calculation - removed unnecessary cast. - removed unnecessary change in smaps. - use GFP_TEMPORARY instead of GFP_KERNEL Signed-off-by: KAMEZAWA Hiroyuki Cc: Matt Mackall Cc: KOSAKI Motohiro Cc: San Mehat Cc: Brian Swetland Cc: Dave Hansen Cc: Andrew Morton [ Fixed kmalloc failure return code as per Matt ] Signed-off-by: Linus Torvalds

oom: fix the unsafe usage of badness() in proc_oom_score()

2010-04-01T15:50:21Z

proc_oom_score(task) has a reference to task_struct, but that is all. If this task was already released before we take tasklist_lock - we can't use task->group_leader, it points to nowhere - it is not safe to call badness() even if this task is ->group_leader, has_intersects_mems_allowed() assumes it is safe to iterate over ->thread_group list. - even worse, badness() can hit ->signal == NULL Add the pid_alive() check to ensure __unhash_process() was not called. Also, use "task" instead of task->group_leader. badness() should return the same result for any sub-thread. Currently this is not true, but this should be changed anyway. Signed-off-by: Oleg Nesterov Cc: stable@kernel.org Signed-off-by: Linus Torvalds

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32Z

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 Guess-its-ok-by: Christoph Lameter Cc: Ingo Molnar Cc: Lee Schermerhorn

kcore: fix test for end of list

2010-03-24T23:31:22Z

"m" is never NULL here. We need a different test for the end of list condition. Signed-off-by: Dan Carpenter Acked-by: KAMEZAWA Hiroyuki Acked-by: WANG Cong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

proc: warn on non-existing proc entries

2010-03-06T19:26:45Z

* warn if creation goes on to non-existent directory * warn if removal goes on from non-existing directory * warn if non-existing proc entry is removed Signed-off-by: Alexey Dobriyan Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds