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* Merge branch 'for-linus' of ↵Linus Torvalds2013-08-251-2/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs fixes from Al Viro: "Assorted fixes from the last week or so" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: VFS: collect_mounts() should return an ERR_PTR bfs: iget_locked() doesn't return an ERR_PTR efs: iget_locked() doesn't return an ERR_PTR() proc: kill the extra proc_readfd_common()->dir_emit_dots() cope with potentially long ->d_dname() output for shmem/hugetlb
| * proc: kill the extra proc_readfd_common()->dir_emit_dots()Oleg Nesterov2013-08-241-2/+0
| | | | | | | | | | | | | | | | proc_readfd_common() does dir_emit_dots() twice in a row, we need to do this only once. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | proc: more readdir conversion bug-fixesLinus Torvalds2013-08-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the previous commit, Richard Genoud fixed proc_root_readdir(), which had lost the check for whether all of the non-process /proc entries had been returned or not. But that in turn exposed _another_ bug, namely that the original readdir conversion patch had yet another problem: it had lost the return value of proc_readdir_de(), so now checking whether it had completed successfully or not didn't actually work right anyway. This reinstates the non-zero return for the "end of base entries" that had also gotten lost in commit f0c3b5093add ("[readdir] convert procfs"). So now you get all the base entries *and* you get all the process entries, regardless of getdents buffer size. (Side note: the Linux "getdents" manual page actually has a nice example application for testing getdents, which can be easily modified to use different buffers. Who knew? Man-pages can be useful) Reported-by: Emmanuel Benisty <benisty.e@gmail.com> Reported-by: Marc Dionne <marc.c.dionne@gmail.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc: return on proc_readdir errorRichard Genoud2013-08-191-1/+3
|/ | | | | | | | | | | | | | | | | | | | | | Commit f0c3b5093add ("[readdir] convert procfs") introduced a bug on the listing of the proc file-system. The return value of proc_readdir() isn't tested anymore in the proc_root_readdir function. This lead to an "interesting" behaviour when we are using the getdents() system call with a buffer too small: instead of failing, it returns the first entries of /proc (enough to fill the given buffer), plus the PID directories. This is not triggered on glibc (as getdents is called with a 32KB buffer), but on uclibc, the buffer size is only 1KB, thus some proc entries are missing. See https://lkml.org/lkml/2013/8/12/288 for more background. Signed-off-by: Richard Genoud <richard.genoud@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/proc/task_mmu.c: fix buffer overflow in add_page_map()yonghua zheng2013-08-131-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | Recently we met quite a lot of random kernel panic issues after enabling CONFIG_PROC_PAGE_MONITOR. After debuggind we found this has something to do with following bug in pagemap: In struct pagemapread: struct pagemapread { int pos, len; pagemap_entry_t *buffer; bool v2; }; pos is number of PM_ENTRY_BYTES in buffer, but len is the size of buffer, it is a mistake to compare pos and len in add_page_map() for checking buffer is full or not, and this can lead to buffer overflow and random kernel panic issue. Correct len to be total number of PM_ENTRY_BYTES in buffer. [akpm@linux-foundation.org: document pagemapread.pos and .len units, fix PM_ENTRY_BYTES definition] Signed-off-by: Yonghua Zheng <younghua.zheng@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: save soft-dirty bits on file pagesCyrill Gorcunov2013-08-131-0/+2
| | | | | | | | | | | | | | | | | | | | | | Andy reported that if file page get reclaimed we lose the soft-dirty bit if it was there, so save _PAGE_BIT_SOFT_DIRTY bit when page address get encoded into pte entry. Thus when #pf happens on such non-present pte we can restore it back. Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: save soft-dirty bits on swapped pagesCyrill Gorcunov2013-08-131-6/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andy Lutomirski reported that if a page with _PAGE_SOFT_DIRTY bit set get swapped out, the bit is getting lost and no longer available when pte read back. To resolve this we introduce _PTE_SWP_SOFT_DIRTY bit which is saved in pte entry for the page being swapped out. When such page is to be read back from a swap cache we check for bit presence and if it's there we clear it and restore the former _PAGE_SOFT_DIRTY bit back. One of the problem was to find a place in pte entry where we can save the _PTE_SWP_SOFT_DIRTY bit while page is in swap. The _PAGE_PSE was chosen for that, it doesn't intersect with swap entry format stored in pte. Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390/kdump: Disable mmap for s390Michael Holzheu2013-07-181-1/+1
| | | | | | | | | | | | | The kdump mmap patch series (git commit 83086978c63afd7c73e1c) directly map the PT_LOADs to memory. On s390 this does not work because the copy_from_oldmem() function swaps [0,crashkernel size] with [crashkernel base, crashkernel base+crashkernel size]. The swap int copy_from_oldmem() was done in order correctly implement /dev/oldmem. See: http://marc.info/?l=kexec&m=136940802511603&w=2 Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* fs/proc/kcore.c: using strlcpy() instead of strncpy()Zhao Hongjiang2013-07-031-1/+1
| | | | | | | | For NUL terminated string, set '\0' at the end. Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/proc/uptime.c:uptime_proc_show(): use get_monotonic_boottime()Oleg Nesterov2013-07-031-2/+1
| | | | | | | | | | | | | Change uptime_proc_show() to use get_monotonic_boottime() instead of do_posix_clock_monotonic_gettime() + monotonic_to_bootbased(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: John Stultz <johnstul@us.ibm.com> Cc: Tomas Janousek <tjanouse@redhat.com> Cc: Tomas Smetana <tsmetana@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmcore: support mmap() on /proc/vmcoreHATAYAMA Daisuke2013-07-031-20/+116
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces mmap_vmcore(). Don't permit writable nor executable mapping even with mprotect() because this mmap() is aimed at reading crash dump memory. Non-writable mapping is also requirement of remap_pfn_range() when mapping linear pages on non-consecutive physical pages; see is_cow_mapping(). Set VM_MIXEDMAP flag to remap memory by remap_pfn_range and by remap_vmalloc_range_pertial at the same time for a single vma. do_munmap() can correctly clean partially remapped vma with two functions in abnormal case. See zap_pte_range(), vm_normal_page() and their comments for details. On x86-32 PAE kernels, mmap() supports at most 16TB memory only. This limitation comes from the fact that the third argument of remap_pfn_range(), pfn, is of 32-bit length on x86-32: unsigned long. [akpm@linux-foundation.org: use min(), switch to conventional error-unwinding approach] Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp> Cc: Lisa Mitchell <lisa.mitchell@hp.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Tested-by: Maxim Uvarov <muvarov@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmcore: calculate vmcore file size from buffer size and total size of vmcore ↵HATAYAMA Daisuke2013-07-031-33/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | objects The previous patches newly added holes before each chunk of memory and the holes need to be count in vmcore file size. There are two ways to count file size in such a way: 1) suppose m is a poitner to the last vmcore object in vmcore_list. Then file size is (m->offset + m->size), or 2) calculate sum of size of buffers for ELF header, program headers, ELF note segments and objects in vmcore_list. Although 1) is more direct and simpler than 2), 2) seems better in that it reflects internal object structure of /proc/vmcore. Thus, this patch changes get_vmcore_size_elf{64, 32} so that it calculates size in the way of 2). As a result, both get_vmcore_size_elf{64, 32} have the same definition. Merge them as get_vmcore_size. Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp> Cc: Lisa Mitchell <lisa.mitchell@hp.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmcore: allow user process to remap ELF note segment bufferHATAYAMA Daisuke2013-07-031-0/+18
| | | | | | | | | | | | | | | | | Now ELF note segment has been copied in the buffer on vmalloc memory. To allow user process to remap the ELF note segment buffer with remap_vmalloc_page, the corresponding VM area object has to have VM_USERMAP flag set. [akpm@linux-foundation.org: use the conventional comment layout] Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp> Cc: Lisa Mitchell <lisa.mitchell@hp.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmcore: allocate ELF note segment in the 2nd kernel vmalloc memoryHATAYAMA Daisuke2013-07-031-73/+286
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The reasons why we don't allocate ELF note segment in the 1st kernel (old memory) on page boundary is to keep backward compatibility for old kernels, and that if doing so, we waste not a little memory due to round-up operation to fit the memory to page boundary since most of the buffers are in per-cpu area. ELF notes are per-cpu, so total size of ELF note segments depends on number of CPUs. The current maximum number of CPUs on x86_64 is 5192, and there's already system with 4192 CPUs in SGI, where total size amounts to 1MB. This can be larger in the near future or possibly even now on another architecture that has larger size of note per a single cpu. Thus, to avoid the case where memory allocation for large block fails, we allocate vmcore objects on vmalloc memory. This patch adds elfnotes_buf and elfnotes_sz variables to keep pointer to the ELF note segment buffer and its size. There's no longer the vmcore object that corresponds to the ELF note segment in vmcore_list. Accordingly, read_vmcore() has new case for ELF note segment and set_vmcore_list_offsets_elf{64,32}() and other helper functions starts calculating offset from sum of size of ELF headers and size of ELF note segment. [akpm@linux-foundation.org: use min(), fix error-path vzalloc() leaks] Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp> Cc: Lisa Mitchell <lisa.mitchell@hp.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmcore: treat memory chunks referenced by PT_LOAD program header entries in ↵HATAYAMA Daisuke2013-07-031-8/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | page-size boundary in vmcore_list Treat memory chunks referenced by PT_LOAD program header entries in page-size boundary in vmcore_list. Formally, for each range [start, end], we set up the corresponding vmcore object in vmcore_list to [rounddown(start, PAGE_SIZE), roundup(end, PAGE_SIZE)]. This change affects layout of /proc/vmcore. The gaps generated by the rearrangement are newly made visible to applications as holes. Concretely, they are two ranges [rounddown(start, PAGE_SIZE), start] and [end, roundup(end, PAGE_SIZE)]. Suppose variable m points at a vmcore object in vmcore_list, and variable phdr points at the program header of PT_LOAD type the variable m corresponds to. Then, pictorially: m->offset +---------------+ | hole | phdr->p_offset = +---------------+ m->offset + (paddr - start) | |\ | kernel memory | phdr->p_memsz | |/ +---------------+ | hole | m->offset + m->size +---------------+ where m->offset and m->offset + m->size are always page-size aligned. Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp> Cc: Lisa Mitchell <lisa.mitchell@hp.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmcore: allocate buffer for ELF headers on page-size alignmentHATAYAMA Daisuke2013-07-031-68/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allocate ELF headers on page-size boundary using __get_free_pages() instead of kmalloc(). Later patch will merge PT_NOTE entries into a single unique one and decrease the buffer size actually used. Keep original buffer size in variable elfcorebuf_sz_orig to kfree the buffer later and actually used buffer size with rounded up to page-size boundary in variable elfcorebuf_sz separately. The size of part of the ELF buffer exported from /proc/vmcore is elfcorebuf_sz. The merged, removed PT_NOTE entries, i.e. the range [elfcorebuf_sz, elfcorebuf_sz_orig], is filled with 0. Use size of the ELF headers as an initial offset value in set_vmcore_list_offsets_elf{64,32} and process_ptload_program_headers_elf{64,32} in order to indicate that the offset includes the holes towards the page boundary. As a result, both set_vmcore_list_offsets_elf{64,32} have the same definition. Merge them as set_vmcore_list_offsets. [akpm@linux-foundation.org: add free_elfcorebuf(), cleanups] Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp> Cc: Lisa Mitchell <lisa.mitchell@hp.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmcore: clean up read_vmcore()HATAYAMA Daisuke2013-07-031-48/+20
| | | | | | | | | | | | | | | Rewrite part of read_vmcore() that reads objects in vmcore_list in the same way as part reading ELF headers, by which some duplicated and redundant codes are removed. Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp> Cc: Lisa Mitchell <lisa.mitchell@hp.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pagemap: prepare to reuse constant bits with page-shiftPavel Emelyanov2013-07-031-1/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | In order to reuse bits from pagemap entries gracefully, we leave the entries as is but on pagemap open emit a warning in dmesg, that bits 55-60 are about to change in a couple of releases. Next, if a user issues soft-dirty clear command via the clear_refs file (it was disabled before v3.9) we assume that he's aware of the new pagemap format, note that fact and report the bits in pagemap in the new manner. The "migration strategy" looks like this then: 1. existing users are not affected -- they don't touch soft-dirty feature, thus see old bits in pagemap, but are warned and have time to fix themselves 2. those who use soft-dirty know about new pagemap format 3. some time soon we get rid of any signs of page-shift in pagemap as well as this trick with clear-soft-dirty affecting pagemap format. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: soft-dirty bits for user memory changes trackingPavel Emelyanov2013-07-031-5/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The soft-dirty is a bit on a PTE which helps to track which pages a task writes to. In order to do this tracking one should 1. Clear soft-dirty bits from PTEs ("echo 4 > /proc/PID/clear_refs) 2. Wait some time. 3. Read soft-dirty bits (55'th in /proc/PID/pagemap2 entries) To do this tracking, the writable bit is cleared from PTEs when the soft-dirty bit is. Thus, after this, when the task tries to modify a page at some virtual address the #PF occurs and the kernel sets the soft-dirty bit on the respective PTE. Note, that although all the task's address space is marked as r/o after the soft-dirty bits clear, the #PF-s that occur after that are processed fast. This is so, since the pages are still mapped to physical memory, and thus all the kernel does is finds this fact out and puts back writable, dirty and soft-dirty bits on the PTE. Another thing to note, is that when mremap moves PTEs they are marked with soft-dirty as well, since from the user perspective mremap modifies the virtual memory at mremap's new address. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pagemap: introduce pagemap_entry_t without pmshift bitsPavel Emelyanov2013-07-031-18/+22
| | | | | | | | | | | | | | | | | These bits are always constant (== PAGE_SHIFT) and just occupy space in the entry. Moreover, in next patch we will need to report one more bit in the pagemap, but all bits are already busy on it. That said, describe the pagemap entry that has 6 more free zero bits. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* clear_refs: introduce private struct for mm_walkPavel Emelyanov2013-07-031-2/+10
| | | | | | | | | | | | | | | In the next patch the clear-refs-type will be required in clear_refs_pte_range funciton, so prepare the walk->private to carry this info. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* clear_refs: sanitize accepted commands declarationPavel Emelyanov2013-07-031-7/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the implementation of the soft-dirty bit concept that should help keep track of changes in user memory, which in turn is very-very required by the checkpoint-restore project (http://criu.org). To create a dump of an application(s) we save all the information about it to files, and the biggest part of such dump is the contents of tasks' memory. However, there are usage scenarios where it's not required to get _all_ the task memory while creating a dump. For example, when doing periodical dumps, it's only required to take full memory dump only at the first step and then take incremental changes of memory. Another example is live migration. We copy all the memory to the destination node without stopping all tasks, then stop them, check for what pages has changed, dump it and the rest of the state, then copy it to the destination node. This decreases freeze time significantly. That said, some help from kernel to watch how processes modify the contents of their memory is required. The proposal is to track changes with the help of new soft-dirty bit this way: 1. First do "echo 4 > /proc/$pid/clear_refs". At that point kernel clears the soft dirty _and_ the writable bits from all ptes of process $pid. From now on every write to any page will result in #pf and the subsequent call to pte_mkdirty/pmd_mkdirty, which in turn will set the soft dirty flag. 2. Then read the /proc/$pid/pagemap2 and check the soft-dirty bit reported there (the 55'th one). If set, the respective pte was written to since last call to clear refs. The soft-dirty bit is the _PAGE_BIT_HIDDEN one. Although it's used by kmemcheck, the latter one marks kernel pages with it, while the former bit is put on user pages so they do not conflict to each other. This patch: A new clear-refs type will be added in the next patch, so prepare code for that. [akpm@linux-foundation.org: don't assume that sizeof(enum clear_refs_types) == sizeof(int)] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Don't pass inode to ->d_hash() and ->d_compare()Linus Torvalds2013-06-291-3/+4
| | | | | | | | | | | | Instances either don't look at it at all (the majority of cases) or only want it to find the superblock (which can be had as dentry->d_sb). A few cases that want more are actually safe with dentry->d_inode - the only precaution needed is the check that it hadn't been replaced with NULL by rmdir() or by overwriting rename(), which case should be simply treated as cache miss. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* proc_fill_cache(): clean up, get rid of pointless find_inode_number() useAl Viro2013-06-291-23/+13
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* proc_fill_cache(): just make instantiate_t return intAl Viro2013-06-294-49/+43
| | | | | | all instances always return ERR_PTR(-E...) or NULL, anyway Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* proc_pid_readdir(): stop wanking with proc_fill_cache() for /proc/selfAl Viro2013-06-291-3/+3
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* proc_fill_cache(): kill pointless checkAl Viro2013-06-291-4/+2
| | | | | | we'd just checked that child->d_inode is non-NULL, for fuck sake! Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [readdir] convert procfsAl Viro2013-06-298-470/+270
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* kmsg: honor dmesg_restrict sysctl on /dev/kmsgKees Cook2013-06-121-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The dmesg_restrict sysctl currently covers the syslog method for access dmesg, however /dev/kmsg isn't covered by the same protections. Most people haven't noticed because util-linux dmesg(1) defaults to using the syslog method for access in older versions. With util-linux dmesg(1) defaults to reading directly from /dev/kmsg. To fix /dev/kmsg, let's compare the existing interfaces and what they allow: - /proc/kmsg allows: - open (SYSLOG_ACTION_OPEN) if CAP_SYSLOG since it uses a destructive single-reader interface (SYSLOG_ACTION_READ). - everything, after an open. - syslog syscall allows: - anything, if CAP_SYSLOG. - SYSLOG_ACTION_READ_ALL and SYSLOG_ACTION_SIZE_BUFFER, if dmesg_restrict==0. - nothing else (EPERM). The use-cases were: - dmesg(1) needs to do non-destructive SYSLOG_ACTION_READ_ALLs. - sysklog(1) needs to open /proc/kmsg, drop privs, and still issue the destructive SYSLOG_ACTION_READs. AIUI, dmesg(1) is moving to /dev/kmsg, and systemd-journald doesn't clear the ring buffer. Based on the comments in devkmsg_llseek, it sounds like actions besides reading aren't going to be supported by /dev/kmsg (i.e. SYSLOG_ACTION_CLEAR), so we have a strict subset of the non-destructive syslog syscall actions. To this end, move the check as Josh had done, but also rename the constants to reflect their new uses (SYSLOG_FROM_CALL becomes SYSLOG_FROM_READER, and SYSLOG_FROM_FILE becomes SYSLOG_FROM_PROC). SYSLOG_FROM_READER allows non-destructive actions, and SYSLOG_FROM_PROC allows destructive actions after a capabilities-constrained SYSLOG_ACTION_OPEN check. - /dev/kmsg allows: - open if CAP_SYSLOG or dmesg_restrict==0 - reading/polling, after open Addresses https://bugzilla.redhat.com/show_bug.cgi?id=903192 [akpm@linux-foundation.org: use pr_warn_once()] Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Christian Kujau <lists@nerdbynature.de> Tested-by: Josh Boyer <jwboyer@redhat.com> Cc: Kay Sievers <kay@vrfy.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* posix-timers: Show clock ID in proc filePavel Tikhomirov2013-05-281-0/+1
| | | | | | | | | | | | | Expand information about posix-timers in /proc/<pid>/timers by adding info about clock, with which the timer was created. I.e. in the forth line of timer info after "notify:" line go "ClockID: <clock_id>". Signed-off-by: Pavel Tikhomirov <snorcht@gmail.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Matthew Helsley <matt.helsley@gmail.com> Cc: Pavel Emelyanov <xemul@parallels.com> Link: http://lkml.kernel.org/r/1368742323-46949-2-git-send-email-snorcht@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'slab/for-linus' of ↵Linus Torvalds2013-05-071-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux Pull slab changes from Pekka Enberg: "The bulk of the changes are more slab unification from Christoph. There's also few fixes from Aaron, Glauber, and Joonsoo thrown into the mix." * 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux: (24 commits) mm, slab_common: Fix bootstrap creation of kmalloc caches slab: Return NULL for oversized allocations mm: slab: Verify the nodeid passed to ____cache_alloc_node slub: tid must be retrieved from the percpu area of the current processor slub: Do not dereference NULL pointer in node_match slub: add 'likely' macro to inc_slabs_node() slub: correct to calculate num of acquired objects in get_partial_node() slub: correctly bootstrap boot caches mm/sl[au]b: correct allocation type check in kmalloc_slab() slab: Fixup CONFIG_PAGE_ALLOC/DEBUG_SLAB_LEAK sections slab: Handle ARCH_DMA_MINALIGN correctly slab: Common definition for kmem_cache_node slab: Rename list3/l3 to node slab: Common Kmalloc cache determination stat: Use size_t for sizes instead of unsigned slab: Common function to create the kmalloc array slab: Common definition for the array of kmalloc caches slab: Common constants for kmalloc boundaries slab: Rename nodelists to node slab: Common name for the per node structures ...
| * Merge branch 'slab/next' into slab/for-linusPekka Enberg2013-05-071-1/+1
| |\
| | * stat: Use size_t for sizes instead of unsignedChristoph Lameter2013-02-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | On some platforms (such as IA64) the large page size may results in slab allocations to be allowed of numbers that do not fit in 32 bit. Acked-by: Glauber Costa <glommer@parallels.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
* | | proc_devtree: Replace include linux/module.h with linux/export.hSyam Sidhardhan2013-05-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Since it uses only THIS_MODULE macro, include <linux/export.h> is the right to go here. Signed-off-by: Syam Sidhardhan <s.syam@samsung.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | Merge branch 'for-linus' of ↵Linus Torvalds2013-05-0112-612/+501
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull VFS updates from Al Viro, Misc cleanups all over the place, mainly wrt /proc interfaces (switch create_proc_entry to proc_create(), get rid of the deprecated create_proc_read_entry() in favor of using proc_create_data() and seq_file etc). 7kloc removed. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits) don't bother with deferred freeing of fdtables proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h proc: Make the PROC_I() and PDE() macros internal to procfs proc: Supply a function to remove a proc entry by PDE take cgroup_open() and cpuset_open() to fs/proc/base.c ppc: Clean up scanlog ppc: Clean up rtas_flash driver somewhat hostap: proc: Use remove_proc_subtree() drm: proc: Use remove_proc_subtree() drm: proc: Use minor->index to label things, not PDE->name drm: Constify drm_proc_list[] zoran: Don't print proc_dir_entry data in debug reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show() proc: Supply an accessor for getting the data from a PDE's parent airo: Use remove_proc_subtree() rtl8192u: Don't need to save device proc dir PDE rtl8187se: Use a dir under /proc/net/r8180/ proc: Add proc_mkdir_data() proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h} proc: Move PDE_NET() to fs/proc/proc_net.c ...
| * | | proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.hDavid Howells2013-05-012-111/+197
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move non-public declarations and definitions from linux/proc_fs.h to fs/proc/internal.h. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | proc: Make the PROC_I() and PDE() macros internal to procfsDavid Howells2013-05-013-2/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the PROC_I() and PDE() macros internal to procfs. This means making PDE_DATA() out of line. This could be made more optimal by storing PDE()->data into inode->i_private. Also provide a __PDE_DATA() that is inline and internal to procfs. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | proc: Supply a function to remove a proc entry by PDEDavid Howells2013-05-012-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Supply a function (proc_remove()) to remove a proc entry (and any subtree rooted there) by proc_dir_entry pointer rather than by name and (optionally) root dir entry pointer. This allows us to eliminate all remaining pde->name accesses outside of procfs. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Grant Likely <grant.likely@linaro.or> cc: linux-acpi@vger.kernel.org cc: openipmi-developer@lists.sourceforge.net cc: devicetree-discuss@lists.ozlabs.org cc: linux-pci@vger.kernel.org cc: netdev@vger.kernel.org cc: netfilter-devel@vger.kernel.org cc: alsa-devel@alsa-project.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | take cgroup_open() and cpuset_open() to fs/proc/base.cAl Viro2013-05-011-0/+31
| | | | | | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | proc: Supply an accessor for getting the data from a PDE's parentDavid Howells2013-05-011-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Supply an accessor function for getting the private data from the parent proc_dir_entry struct of the proc_dir_entry struct associated with an inode. ReiserFS, for instance, stores the super_block pointer in the proc directory it makes for that super_block, and a pointer to the respective seq_file show function in each of the proc files in that directory. This allows a reduction in the number of file_operations structs, open functions and seq_operations structs required. The problem otherwise is that each show function requires two pieces of data but only has storage for one per PDE (and this has no release function). Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Jerry Chuang <jerry-chuang@realtek.com> cc: Maxim Mikityanskiy <maxtram95@gmail.com> cc: YAMANE Toshiaki <yamanetoshi@gmail.com> cc: linux-wireless@vger.kernel.org cc: linux-scsi@vger.kernel.org cc: devel@driverdev.osuosl.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | proc: Add proc_mkdir_data()David Howells2013-05-011-18/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add proc_mkdir_data() to allow procfs directories to be created that are annotated at the time of creation with private data rather than doing this post-creation. This means no access is then required to the proc_dir_entry struct to set this. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Neela Syam Kolli <megaraidlinux@lsi.com> cc: Jerry Chuang <jerry-chuang@realtek.com> cc: linux-scsi@vger.kernel.org cc: devel@driverdev.osuosl.org cc: linux-wireless@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}David Howells2013-05-011-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move some bits from linux/proc_fs.h to linux/of.h, signal.h and tty.h. Also move proc_tty_init() and proc_device_tree_init() to fs/proc/internal.h as they're internal to procfs. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Grant Likely <grant.likely@secretlab.ca> cc: devicetree-discuss@lists.ozlabs.org cc: linux-arch@vger.kernel.org cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Jri Slaby <jslaby@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | proc: Move PDE_NET() to fs/proc/proc_net.cDavid Howells2013-05-011-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Move PDE_NET() to fs/proc/proc_net.c as that's where the only user is. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | proc: Split the namespace stuff out into linux/proc_ns.hDavid Howells2013-05-012-10/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split the proc namespace stuff out into linux/proc_ns.h. Signed-off-by: David Howells <dhowells@redhat.com> cc: netdev@vger.kernel.org cc: Serge E. Hallyn <serge.hallyn@ubuntu.com> cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | proc: Move proc_fd() to fs/proc/fd.hDavid Howells2013-05-012-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Move proc_fd() to fs/proc/fd.h. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | proc: Uninline pid_delete_dentry()David Howells2013-05-012-9/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Uninline pid_delete_dentry() as it's only used by three function pointers. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | proc: Supply PDE attribute setting accessor functionsDavid Howells2013-05-011-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Supply accessor functions to set attributes in proc_dir_entry structs. The following are supplied: proc_set_size() and proc_set_user(). Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com> cc: linuxppc-dev@lists.ozlabs.org cc: linux-media@vger.kernel.org cc: netdev@vger.kernel.org cc: linux-wireless@vger.kernel.org cc: linux-pci@vger.kernel.org cc: netfilter-devel@vger.kernel.org cc: alsa-devel@alsa-project.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | proc: Split kcore bits from linux/procfs.h into linux/kcore.hDavid Howells2013-04-292-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split kcore bits from linux/procfs.h into linux/kcore.h. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> cc: linux-mips@linux-mips.org cc: sparclinux@vger.kernel.org cc: x86@kernel.org cc: linux-mm@kvack.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | Include missing linux/magic.h inclusionsDavid Howells2013-04-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Include missing linux/magic.h inclusions where the source file is currently expecting to get magic numbers through linux/proc_fs.h. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-efi@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | Include missing linux/slab.h inclusionsDavid Howells2013-04-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Include missing linux/slab.h inclusions where the source file is currently expecting to get kmalloc() and co. through linux/proc_fs.h. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: linux-s390@vger.kernel.org cc: sparclinux@vger.kernel.org cc: linux-efi@vger.kernel.org cc: linux-mtd@lists.infradead.org cc: devel@driverdev.osuosl.org cc: x86@kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
generated by cgit v1.1 at 2024-12-24 13:53:40 +0000