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path: root/fs/proc/task_mmu.c
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2009-01-06mm: report the MMU pagesize in /proc/pid/smapsMel Gorman
The KernelPageSize entry in /proc/pid/smaps is the pagesize used by the kernel to back a VMA. This matches the size used by the MMU in the majority of cases. However, one counter-example occurs on PPC64 kernels whereby a kernel using 64K as a base pagesize may still use 4K pages for the MMU on older processor. To distinguish, this patch reports MMUPageSize as the pagesize used by the MMU in /proc/pid/smaps. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: "KOSAKI Motohiro" <kosaki.motohiro@jp.fujitsu.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06mm: report the pagesize backing a VMA in /proc/pid/smapsMel Gorman
It is useful to verify a hugepage-aware application is using the expected pagesizes for its memory regions. This patch creates an entry called KernelPageSize in /proc/pid/smaps that is the size of page used by the kernel to back a VMA. The entry is not called PageSize as it is possible the MMU uses a different size. This extension should not break any sensible parser that skips lines containing unrecognised information. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: "KOSAKI Motohiro" <kosaki.motohiro@jp.fujitsu.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10pagemap: fix 32-bit pagemap regressionMatt Mackall
The large pages fix from bcf8039ed45 broke 32-bit pagemap by pulling the pagemap entry code out into a function with the wrong return type. Pagemap entries are 64 bits on all systems and unsigned long is only 32 bits on 32-bit systems. Signed-off-by: Matt Mackall <mpm@selenic.com> Reported-by: Doug Graham <dgraham@nortel.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: <stable@kernel.org> [2.6.26.x, 2.6.27.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-23proc: fix vma display mismatch between /proc/pid/{maps,smaps}Joe Korty
Commit 4752c369789250eafcd7813e11c8fb689235b0d2 aka "maps4: simplify interdependence of maps and smaps" broke /proc/pid/smaps, causing it to display some vmas twice and other vmas not at all. For example: grep .- /proc/1/smaps >/tmp/smaps; diff /proc/1/maps /tmp/smaps 1 25d24 2 < 7fd7e23aa000-7fd7e23ac000 rw-p 7fd7e23aa000 00:00 0 3 28a28 4 > ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] The bug has something to do with setting m->version before all the seq_printf's have been performed. show_map was doing this correctly, but show_smap was doing this in the middle of its seq_printf sequence. This patch arranges things so that the setting of m->version in show_smap is also done at the end of its seq_printf sequence. Testing: in addition to the above grep test, for each process I summed up the 'Rss' fields of /proc/pid/smaps and compared that to the 'VmRSS' field of /proc/pid/status. All matched except for Xorg (which has a /dev/mem mapping which Rss accounts for but VmRSS does not). This result gives us some confidence that neither /proc/pid/maps nor /proc/pid/smaps are any longer skipping or double-counting vmas. Signed-off-by: Joe Korty <joe.korty@ccur.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2008-10-10proc: remove kernel.maps_protectAlexey Dobriyan
After commit 831830b5a2b5d413407adf380ef62fe17d6fcbf2 aka "restrict reading from /proc/<pid>/maps to those who share ->mm or can ptrace" sysctl stopped being relevant because commit moved security checks from ->show time to ->start time (mm_for_maps()). Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Kees Cook <kees.cook@canonical.com>
2008-08-20/proc/self/maps doesn't display the real file offsetClement Calmels
This addresses http://bugzilla.kernel.org/show_bug.cgi?id=11318 In function show_map (file: fs/proc/task_mmu.c), if vma->vm_pgoff > 2^20 than (vma->vm_pgoff << PAGE_SIZE) is greater than 2^32 (with PAGE_SIZE equal to 4096 (i.e. 2^12). The next seq_printf use an unsigned long for the conversion of (vma->vm_pgoff << PAGE_SIZE), as a result the offset value displayed in /proc/self/maps is truncated if the page offset is greater than 2^20. A test that shows this issue: #define _GNU_SOURCE #include <sys/types.h> #include <sys/stat.h> #include <sys/mman.h> #include <stdlib.h> #include <stdio.h> #include <fcntl.h> #include <unistd.h> #include <string.h> #define PAGE_SIZE (getpagesize()) #if __i386__ # define U64_STR "%llx" #elif __x86_64 # define U64_STR "%lx" #else # error "Architecture Unsupported" #endif int main(int argc, char *argv[]) { int fd; char *addr; off64_t offset = 0x10000000; char *filename = "/dev/zero"; fd = open(filename, O_RDONLY); if (fd < 0) { perror("open"); return 1; } offset *= 0x10; printf("offset = " U64_STR "\n", offset); addr = (char*)mmap64(NULL, PAGE_SIZE, PROT_READ, MAP_PRIVATE, fd, offset); if ((void*)addr == MAP_FAILED) { perror("mmap64"); return 1; } { FILE *fmaps; char *line = NULL; size_t len = 0; ssize_t read; size_t filename_len = strlen(filename); fmaps = fopen("/proc/self/maps", "r"); if (!fmaps) { perror("fopen"); return 1; } while ((read = getline(&line, &len, fmaps)) != -1) { if ((read > filename_len + 1) && (strncmp(&line[read - filename_len - 1], filename, filename_len) == 0)) printf("%s", line); } if (line) free(line); fclose(fmaps); } close(fd); return 0; } [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Clement Calmels <cboulte@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-22proc: fix /proc/*/pagemap some moreAlexey Dobriyan
struct pagemap_walk was placed on stack, some hooks are initialized, the rest (->pgd_entry, ->pud_entry, ->pte_entry) are valid but junk. Reported-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Vegard Nossum" <vegard.nossum@gmail.com> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-14Security: split proc ptrace checking into read vs. attachStephen Smalley
Enable security modules to distinguish reading of process state via proc from full ptrace access by renaming ptrace_may_attach to ptrace_may_access and adding a mode argument indicating whether only read access or full attach access is requested. This allows security modules to permit access to reading process state without granting full ptrace access. The base DAC/capability checking remains unchanged. Read access to /proc/pid/mem continues to apply a full ptrace attach check since check_mem_permission() already requires the current task to already be ptracing the target. The other ptrace checks within proc for elements like environ, maps, and fds are changed to pass the read mode instead of attach. In the SELinux case, we model such reading of process state as a reading of a proc file labeled with the target process' label. This enables SELinux policy to permit such reading of process state without permitting control or manipulation of the target process, as there are a number of cases where programs probe for such information via proc but do not need to be able to control the target (e.g. procps, lsof, PolicyKit, ConsoleKit). At present we have to choose between allowing full ptrace in policy (more permissive than required/desired) or breaking functionality (or in some cases just silencing the denials via dontaudit rules but this can hide genuine attacks). This version of the patch incorporates comments from Casey Schaufler (change/replace existing ptrace_may_attach interface, pass access mode), and Chris Wright (provide greater consistency in the checking). Note that like their predecessors __ptrace_may_attach and ptrace_may_attach, the __ptrace_may_access and ptrace_may_access interfaces use different return value conventions from each other (0 or -errno vs. 1 or 0). I retained this difference to avoid any changes to the caller logic but made the difference clearer by changing the latter interface to return a bool rather than an int and by adding a comment about it to ptrace.h for any future callers. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: James Morris <jmorris@namei.org>
2008-07-05Fix pagemap_read() use of struct mm_walkAndrew Morton
Fix some issues in pagemap_read noted by Alexey: - initialize pagemap_walk.mm to "mm" , so the code starts working as advertised - initialize ->private to "&pm" so it wouldn't immediately oops in pagemap_pte_hole() - unstatic struct pagemap_walk, so two threads won't fsckup each other (including those started by root, including flipping ->mm when you don't have permissions) - pagemap_read() contains two calls to ptrace_may_attach(), second one looks unneeded. - avoid possible kmalloc(0) and integer wraparound. Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ Personally, I'd just remove the functionality entirely - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-05Fix clear_refs_write() use of struct mm_walkAndrew Morton
Don't use a static entry, so as to prevent races during concurrent use of this function. Reported-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12pagemap: fix large pages in pagemapDave Hansen
We were walking right into huge page areas in the pagemap walker, and calling the pmds pmd_bad() and clearing them. That leaked huge pages. Bad. This patch at least works around that for now. It ignores huge pages in the pagemap walker for the time being, and won't leak those pages. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12pagemap: pass mm into pagewalkersDave Hansen
We need this at least for huge page detection for now, because powerpc needs the vm_area_struct to be able to determine whether a virtual address is referring to a huge page (its pmd_huge() doesn't work). It might also come in handy for some of the other users. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06pagemap: fix bug in add_to_pagemap, require aligned-length reads of ↵Thomas Tuttle
/proc/pid/pagemap Fix a bug in add_to_pagemap. Previously, since pm->out was a char *, put_user was only copying 1 byte of every PFN, resulting in the top 7 bytes of each PFN not being copied. By requiring that reads be a multiple of 8 bytes, I can make pm->out and pm->end u64*s instead of char*s, which makes put_user work properly, and also simplifies the logic in add_to_pagemap a bit. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Thomas Tuttle <ttuttle@google.com> Cc: Matt Mackall <mpm@selenic.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-08fs/proc/task_mmu.c: remove duplicated include filesHuang Weiyi
Removed duplicated include files <linux/ptrace.h> and <linux/seq_file.h> in fs/proc/task_mmu.c. Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29procfs task exe symlinkMatt Helsley
The kernel implements readlink of /proc/pid/exe by getting the file from the first executable VMA. Then the path to the file is reconstructed and reported as the result. Because of the VMA walk the code is slightly different on nommu systems. This patch avoids separate /proc/pid/exe code on nommu systems. Instead of walking the VMAs to find the first executable file-backed VMA we store a reference to the exec'd file in the mm_struct. That reference would prevent the filesystem holding the executable file from being unmounted even after unmapping the VMAs. So we track the number of VM_EXECUTABLE VMAs and drop the new reference when the last one is unmapped. This avoids pinning the mounted filesystem. [akpm@linux-foundation.org: improve comments] [yamamoto@valinux.co.jp: fix dup_mmap] Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: David Howells <dhowells@redhat.com> Cc:"Eric W. Biederman" <ebiederm@xmission.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28smaps: account swap entriesPeter Zijlstra
Show the amount of swap for each vma. This can be used to see where all the swap goes. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Matt Mackall <mpm@selenic.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28make swap_pte_to_pagemap_entry() staticAdrian Bunk
Make the needlessly global swap_pte_to_pagemap_entry() static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-22Change pagemap output format to allow for future reporting of huge pagesHans Rosenfeld
Change pagemap output format to allow for future reporting of huge pages. (Format comment and minor cleanups: mpm@selenic.com) Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com> Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-13pagemap: proper read error handlingMarcelo Tosatti
Fix pagemap_read() error handling by releasing acquired resources and checking for get_user_pages() partial failure. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-23/proc/pid/pagemap: fix PM_SPECIAL macroHans Rosenfeld
There seems to be a bug in the PM_SPECIAL macro for /proc/pid/pagemap. I think masking out those other bits makes more sense then setting all those mask bits. Signed-off-by: Hans Rosenfeld <Hans.Rosenfeld@amd.com> Acked-by: Matt Mackall <mpm@selenic.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14d_path: Make seq_path() use a struct path argumentJan Blunck
seq_path() is always called with a dentry and a vfsmount from a struct path. Make seq_path() take it directly as an argument. Signed-off-by: Jan Blunck <jblunck@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14d_path: Make proc_get_link() use a struct path argumentJan Blunck
proc_get_link() is always called with a dentry and a vfsmount from a struct path. Make proc_get_link() take it directly as an argument. Signed-off-by: Jan Blunck <jblunck@suse.de> Acked-by: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Neil Brown <neilb@suse.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08procfs: constify function pointer tablesJan Engelhardt
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Mike Frysinger <vapier@gentoo.org> Acked-By: David Howells <dhowells@redhat.com> Acked-by: Bryan Wu <bryan.wu@analog.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08proc: seqfile convert proc_pid_status to properly handle pid namespacesEric W. Biederman
Currently we possibly lookup the pid in the wrong pid namespace. So seq_file convert proc_pid_status which ensures the proper pid namespaces is passed in. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: another build fix] [akpm@linux-foundation.org: s390 build fix] [akpm@linux-foundation.org: fix task_name() output] [akpm@linux-foundation.org: fix nommu build] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Andrew Morgan <morgan@kernel.org> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Paul Jackson <pj@sgi.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05maps4: make page monitoring /proc file optionalMatt Mackall
Make /proc/ page monitoring configurable This puts the following files under an embedded config option: /proc/pid/clear_refs /proc/pid/smaps /proc/pid/pagemap /proc/kpagecount /proc/kpageflags [akpm@linux-foundation.org: Kconfig fix] Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05maps4: add /proc/pid/pagemap interfaceMatt Mackall
This interface provides a mapping for each page in an address space to its physical page frame number, allowing precise determination of what pages are mapped and what pages are shared between processes. New in this version: - headers gone again (as recommended by Dave Hansen and Alan Cox) - 64-bit entries (as per discussion with Andi Kleen) - swap pte information exported (from Dave Hansen) - page walker callback for holes (from Dave Hansen) - direct put_user I/O (as suggested by Rusty Russell) This patch folds in cleanups and swap PTE support from Dave Hansen <haveblue@us.ibm.com>. Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05maps4: regroup task_mmu by interfaceMatt Mackall
Reorder source so that all the code and data for each interface is together. Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: David Rientjes <rientjes@google.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05maps4: move clear_refs code to task_mmu.cMatt Mackall
This puts all the clear_refs code where it belongs and probably lets things compile on MMU-less systems as well. Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: David Rientjes <rientjes@google.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05maps4: simplify interdependence of maps and smapsMatt Mackall
This pulls the shared map display code out of show_map and puts it in show_smap where it belongs. Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Acked-by: David Rientjes <rientjes@google.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05maps4: use pagewalker in clear_refs and smapsMatt Mackall
Use the generic pagewalker for smaps and clear_refs Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05maps4: add proportional set size accounting in smapsFengguang Wu
The "proportional set size" (PSS) of a process is the count of pages it has in memory, where each page is divided by the number of processes sharing it. So if a process has 1000 pages all to itself, and 1000 shared with one other process, its PSS will be 1500. - lwn.net: "ELC: How much memory are applications really using?" The PSS proposed by Matt Mackall is a very nice metic for measuring an process's memory footprint. So collect and export it via /proc/<pid>/smaps. Matt Mackall's pagemap/kpagemap and John Berthels's exmap can also do the job. They are comprehensive tools. But for PSS, let's do it in the simple way. Cc: John Berthels <jjberthels@gmail.com> Cc: Bernardo Innocenti <bernie@codewiz.org> Cc: Padraig Brady <P@draigBrady.com> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn> Cc: Hugh Dickins <hugh@veritas.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-02restrict reading from /proc/<pid>/maps to those who share ->mm or can ptrace pidAl Viro
Contents of /proc/*/maps is sensitive and may become sensitive after open() (e.g. if target originally shares our ->mm and later does exec on suid-root binary). Check at read() (actually, ->start() of iterator) time that mm_struct we'd grabbed and locked is - still the ->mm of target - equal to reader's ->mm or the target is ptracable by reader. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08proc: maps protectionKees Cook
The /proc/pid/ "maps", "smaps", and "numa_maps" files contain sensitive information about the memory location and usage of processes. Issues: - maps should not be world-readable, especially if programs expect any kind of ASLR protection from local attackers. - maps cannot just be 0400 because "-D_FORTIFY_SOURCE=2 -O2" makes glibc check the maps when %n is in a *printf call, and a setuid(getuid()) process wouldn't be able to read its own maps file. (For reference see http://lkml.org/lkml/2006/1/22/150) - a system-wide toggle is needed to allow prior behavior in the case of non-root applications that depend on access to the maps contents. This change implements a check using "ptrace_may_attach" before allowing access to read the maps contents. To control this protection, the new knob /proc/sys/kernel/maps_protect has been added, with corresponding updates to the procfs documentation. [akpm@linux-foundation.org: build fixes] [akpm@linux-foundation.org: New sysctl numbers are old hat] Signed-off-by: Kees Cook <kees@outflux.net> Cc: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07smaps: add clear_refs file to clear referenceDavid Rientjes
Adds /proc/pid/clear_refs. When any non-zero number is written to this file, pte_mkold() and ClearPageReferenced() is called for each pte and its corresponding page, respectively, in that task's VMAs. This file is only writable by the user who owns the task. It is now possible to measure _approximately_ how much memory a task is using by clearing the reference bits with echo 1 > /proc/pid/clear_refs and checking the reference count for each VMA from the /proc/pid/smaps output at a measured time interval. For example, to observe the approximate change in memory footprint for a task, write a script that clears the references (echo 1 > /proc/pid/clear_refs), sleeps, and then greps for Pgs_Referenced and extracts the size in kB. Add the sizes for each VMA together for the total referenced footprint. Moments later, repeat the process and observe the difference. For example, using an efficient Mozilla: accumulated time referenced memory ---------------- ----------------- 0 s 408 kB 1 s 408 kB 2 s 556 kB 3 s 1028 kB 4 s 872 kB 5 s 1956 kB 6 s 416 kB 7 s 1560 kB 8 s 2336 kB 9 s 1044 kB 10 s 416 kB This is a valuable tool to get an approximate measurement of the memory footprint for a task. Cc: Hugh Dickins <hugh@veritas.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: David Rientjes <rientjes@google.com> [akpm@linux-foundation.org: build fixes] [mpm@selenic.com: rename for_each_pmd] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07smaps: add pages referenced count to smapsDavid Rientjes
Adds an additional unsigned long field to struct mem_size_stats called 'referenced'. For each pte walked in the smaps code, this field is incremented by PAGE_SIZE if it has pte-reference bits. An additional line was added to the /proc/pid/smaps output for each VMA to indicate how many pages within it are currently marked as referenced or accessed. Cc: Hugh Dickins <hugh@veritas.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07smaps: extract pmd walker from smaps codeDavid Rientjes
Extracts the pmd walker from smaps-specific code in fs/proc/task_mmu.c. The new struct pmd_walker includes the struct vm_area_struct of the memory to walk over. Iteration begins at the vma->vm_start and completes at vma->vm_end. A pointer to another data structure may be stored in the private field such as struct mem_size_stats, which acts as the smaps accumulator. For each pmd in the VMA, the action function is called with a pointer to its struct vm_area_struct, a pointer to the pmd_t, its start and end addresses, and the private field. The interface for walking pmd's in a VMA for fs/proc/task_mmu.c is now: void for_each_pmd(struct vm_area_struct *vma, void (*action)(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end, void *private), void *private); Since the pmd walker is now extracted from the smaps code, smaps_one_pmd() is invoked for each pmd in the VMA. Its behavior and efficiency is identical to the existing implementation. Cc: Hugh Dickins <hugh@veritas.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] mark struct file_operations const 6Arjan van de Ven
Many struct file_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-08[PATCH] proc: change uses of f_{dentry, vfsmnt} to use f_pathJosef "Jeff" Sipek
Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in the proc filesystem code. Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27[PATCH] NOMMU: move the fallback arch_vma_name() to a sensible placeDavid Howells
Move the fallback arch_vma_name() to a sensible place (kernel/signal.c). Currently it's in fs/proc/task_mmu.c, a file that is dependent on both CONFIG_PROC_FS and CONFIG_MMU being enabled, but it's used from kernel/signal.c from where it is called unconditionally. [akpm@osdl.org: build fix] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27[PATCH] vdso: randomize the i386 vDSO by moving it into a vmaIngo Molnar
Move the i386 VDSO down into a vma and thus randomize it. Besides the security implications, this feature also helps debuggers, which can COW a vma-backed VDSO just like a normal DSO and can thus do single-stepping and other debugging features. It's good for hypervisors (Xen, VMWare) too, which typically live in the same high-mapped address space as the VDSO, hence whenever the VDSO is used, they get lots of guest pagefaults and have to fix such guest accesses up - which slows things down instead of speeding things up (the primary purpose of the VDSO). There's a new CONFIG_COMPAT_VDSO (default=y) option, which provides support for older glibcs that still rely on a prelinked high-mapped VDSO. Newer distributions (using glibc 2.3.3 or later) can turn this option off. Turning it off is also recommended for security reasons: attackers cannot use the predictable high-mapped VDSO page as syscall trampoline anymore. There is a new vdso=[0|1] boot option as well, and a runtime /proc/sys/vm/vdso_enabled sysctl switch, that allows the VDSO to be turned on/off. (This version of the VDSO-randomization patch also has working ELF coredumping, the previous patch crashed in the coredumping code.) This code is a combined work of the exec-shield VDSO randomization code and Gerd Hoffmann's hypervisor-centric VDSO patch. Rusty Russell started this patch and i completed it. [akpm@osdl.org: cleanups] [akpm@osdl.org: compile fix] [akpm@osdl.org: compile fix 2] [akpm@osdl.org: compile fix 3] [akpm@osdl.org: revernt MAXMEM change] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@infradead.org> Cc: Gerd Hoffmann <kraxel@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Zachary Amsden <zach@vmware.com> Cc: Andi Kleen <ak@muc.de> Cc: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Use struct pid not struct task_refEric W. Biederman
Incrementally update my proc-dont-lock-task_structs-indefinitely patches so that they work with struct pid instead of struct task_ref. Mostly this is a straight 1-1 substitution. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: don't lock task_structs indefinitelyEric W. Biederman
Every inode in /proc holds a reference to a struct task_struct. If a directory or file is opened and remains open after the the task exits this pinning continues. With 8K stacks on a 32bit machine the amount pinned per file descriptor is about 10K. Normally I would figure a reasonable per user process limit is about 100 processes. With 80 processes, with a 1000 file descriptors each I can trigger the 00M killer on a 32bit kernel, because I have pinned about 800MB of useless data. This patch replaces the struct task_struct pointer with a pointer to a struct task_ref which has a struct task_struct pointer. The so the pinning of dead tasks does not happen. The code now has to contend with the fact that the task may now exit at any time. Which is a little but not muh more complicated. With this change it takes about 1000 processes each opening up 1000 file descriptors before I can trigger the OOM killer. Much better. [mlp@google.com: task_mmu small fixes] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Paul Jackson <pj@sgi.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Albert Cahalan <acahalan@gmail.com> Signed-off-by: Prasanna Meda <mlp@google.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Move proc_maps_operations into task_mmu.cEric W. Biederman
All of the functions for proc_maps_operations are already defined in task_mmu.c so move the operations structure to keep the functionality together. Since task_nommu.c implements a dummy version of /proc/<pid>/maps give it a simplified version of proc_maps_operations that it can modify to best suit its needs. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-06[PATCH] smaps: shared fixNick Piggin
The point of the smaps "shared" is to count the number of pages that are mapped by more than one process, according to Mauricio Lin. However, smaps uses page_count for this, so it will return a false positive for every page that is mapped by just that one process, which is also in pagecache or swapcache. There are false positive situations for anonymous pages not in swapcache as well: - page reclaim, migration - get_user_pages (eg. direct-io, ptrace) Use page_mapcount instead, to count the number of mappings to the page. Use vm_normal_page so that weird things like /dev/mem aren't counted either. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-06[PATCH] smaps: hugepages fixNick Piggin
smaps doesn't have a hugepage pagetable walker. Skip walking hugepage vmas. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] Fold numa_maps into mempolicies.cChristoph Lameter
First discussed at http://marc.theaimsgroup.com/?t=113149255100001&r=1&w=2 - Use the check_range() in mempolicy.c to gather statistics. - Improve the numa_maps code in general and fix some comments. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-28mm: re-architect the VM_UNPAGED logicLinus Torvalds
This replaces the (in my opinion horrible) VM_UNMAPPED logic with very explicit support for a "remapped page range" aka VM_PFNMAP. It allows a VM area to contain an arbitrary range of page table entries that the VM never touches, and never considers to be normal pages. Any user of "remap_pfn_range()" automatically gets this new functionality, and doesn't even have to mark the pages reserved or indeed mark them any other way. It just works. As a side effect, doing mmap() on /dev/mem works for arbitrary ranges. Sparc update from David in the next commit. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13[PATCH] Fix sparse warning in proc/task_mmu.cLuiz Fernando Capitulino
fs/proc/task_mmu.c:198:33: warning: Using plain integer as NULL pointer Signed-off-by: Luiz Capitulino <lcapitulino@mandriva.com.br> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] mm: follow_page with inner ptlockHugh Dickins
Final step in pushing down common core's page_table_lock. follow_page no longer wants caller to hold page_table_lock, uses pte_offset_map_lock itself; and so no page_table_lock is taken in get_user_pages itself. But get_user_pages (and get_futex_key) do then need follow_page to pin the page for them: take Daniel's suggestion of bitflags to follow_page. Need one for WRITE, another for TOUCH (it was the accessed flag before: vanished along with check_user_page_readable, but surely get_numa_maps is wrong to mark every page it finds as accessed), another for GET. And another, ANON to dispose of untouched_anonymous_page: it seems silly for that to descend a second time, let follow_page observe if there was no page table and return ZERO_PAGE if so. Fix minor bug in that: check VM_LOCKED - make_pages_present ought to make readonly anonymous present. Give get_numa_maps a cond_resched while we're there. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] mm: pte_offset_map_lock loopsHugh Dickins
Convert those common loops using page_table_lock on the outside and pte_offset_map within to use just pte_offset_map_lock within instead. These all hold mmap_sem (some exclusively, some not), so at no level can a page table be whipped away from beneath them. But whereas pte_alloc loops tested with the "atomic" pmd_present, these loops are testing with pmd_none, which on i386 PAE tests both lower and upper halves. That's now unsafe, so add a cast into pmd_none to test only the vital lower half: we lose a little sensitivity to a corrupt middle directory, but not enough to worry about. It appears that i386 and UML were the only architectures vulnerable in this way, and pgd and pud no problem. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>