- 24 May, 2016 40 commits
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Minfei Huang authored
For some arch, kexec shall map the reserved pages, then use them, when we try to start the kdump service. kexec may return directly, without unmaping the reserved pages, if it fails during starting service. To fix it, we make a pair of map/unmap reserved pages both in generic path and error path. This patch only affects s390. Other architecturess don't implement the interface of crash_unmap_reserved_pages and crash_map_reserved_pages. It isn't a urgent patch. Kernel can work well without any risk, although the reserved pages are not unmapped before returning in error path. Signed-off-by:
Minfei Huang <mnfhuang@gmail.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Xunlei Pang <xlpang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Xunlei Pang authored
Implement the protection method for the crash kernel memory reservation for the 64-bit x86 kdump. Signed-off-by:
Xunlei Pang <xlpang@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Dave Young <dyoung@redhat.com> Cc: Minfei Huang <mhuang@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by:
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Xunlei Pang authored
For the cases that some kernel (module) path stamps the crash reserved memory(already mapped by the kernel) where has been loaded the second kernel data, the kdump kernel will probably fail to boot when panic happens (or even not happens) leaving the culprit at large, this is unacceptable. The patch introduces a mechanism for detecting such cases: 1) After each crash kexec loading, it simply marks the reserved memory regions readonly since we no longer access it after that. When someone stamps the region, the first kernel will panic and trigger the kdump. The weak arch_kexec_protect_crashkres() is introduced to do the actual protection. 2) To allow multiple loading, once 1) was done we also need to remark the reserved memory to readwrite each time a system call related to kdump is made. The weak arch_kexec_unprotect_crashkres() is introduced to do the actual protection. The architecture can make its specific implementation by overriding arch_kexec_protect_crashkres() and arch_kexec_unprotect_crashkres(). Signed-off-by:
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Oleg Nesterov authored
remove_arg_zero() does free_arg_page() for no reason. This was needed before and only if CONFIG_MMU=y: see commit 4fc75ff4 ("exec: fix remove_arg_zero"), install_arg_page() was called for every page != NULL in bprm->page[] array. Today install_arg_page() has already gone and free_arg_page() is nop after another commit b6a2fea3 ("mm: variable length argument support"). CONFIG_MMU=n does free_arg_pages() in free_bprm() and thus it doesn't need remove_arg_zero()->free_arg_page() too; apart from get_arg_page() it never checks if the page in bprm->page[] was allocated or not, so the "extra" non-freed page is fine. OTOH, this free_arg_page() can add the minor pessimization, the caller is going to do copy_strings_kernel() right after remove_arg_zero() which will likely need to re-allocate the same page again. And as Hujunjie pointed out, the "offset == PAGE_SIZE" check is wrong because we are going to increment bprm->p once again before return, so CONFIG_MMU=n "leaks" the page anyway if '0' is the final byte in this page. NOTE: remove_arg_zero() assumes that argv[0] is null-terminated but this is not necessarily true. copy_strings() does "len = strnlen_user(...)", then copy_from_user(len) but another thread or debuger can overwrite the trailing '0' in between. Afaics nothing really bad can happen because we must always have the null-terminated bprm->filename copied by the 1st copy_strings_kernel(), but perhaps we should change this code to check "bprm->p < bprm->exec" anyway, and/or change copy_strings() to ensure that the last byte in string is always zero. Link: http://lkml.kernel.org/r/20160517155335.GA31435@redhat.comSigned-off-by:
Oleg Nesterov <oleg@redhat.com> Reported by: hujunjie <jj.net@163.com> Signed-off-by:
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Andi Kleen authored
Linux preallocates the task structs of the idle tasks for all possible CPUs. This currently means they all end up on node 0. This also implies that the cache line of MWAIT, which is around the flags field in the task struct, are all located in node 0. We see a noticeable performance improvement on Knights Landing CPUs when the cache lines used for MWAIT are located in the local nodes of the CPUs using them. I would expect this to give a (likely slight) improvement on other systems too. The patch implements placing the idle task in the node of its CPUs, by passing the right target node to copy_process() [akpm@linux-foundation.org: use NUMA_NO_NODE, not a bare -1] Link: http://lkml.kernel.org/r/1463492694-15833-1-git-send-email-andi@firstfloor.orgSigned-off-by:
Andi Kleen <ak@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Oleg Nesterov authored
All the users of siginmask() must ensure that sig < SIGRTMIN. sig_fatal() doesn't and this is wrong: UBSAN: Undefined behaviour in kernel/signal.c:911:6 shift exponent 32 is too large for 32-bit type 'long unsigned int' the patch doesn't add the neccesary check to sig_fatal(), it moves the check into siginmask() and updates other callers. Link: http://lkml.kernel.org/r/20160517195052.GA15187@redhat.comReported-by:
Meelis Roos <mroos@linux.ee> Signed-off-by:
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Wang Xiaoqiang authored
Use pr_<level> instead of printk(KERN_<LEVEL> ). Signed-off-by:
Wang Xiaoqiang <wangxq10@lzu.edu.cn> Signed-off-by:
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Tetsuo Handa authored
Currently the size of "struct signal_struct"->oom_flags member is sizeof(unsigned) bytes, but only one flag OOM_FLAG_ORIGIN which is updated by current thread is defined. We can convert OOM_FLAG_ORIGIN into a bool, and reuse the saved bytes for updating from the OOM killer and/or the OOM reaper thread. By the way, do we care about a race window between run_store() and swapoff() because it would be theoretically possible that two threads sharing the "struct signal_struct" concurrently call respective functions? If we care, we can make oom_flags an atomic_t. Signed-off-by:
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Hugh Dickins <hughd@google.com> Signed-off-by:
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Oleg Nesterov authored
I see no reason why waitid() can't support other linux-specific flags allowed in sys_wait4(). In particular this change can help if we reconsider the previous change ("wait/ptrace: assume __WALL if the child is traced") which adds the "automagical" __WALL for debugger. Signed-off-by: -
Oleg Nesterov authored
The following program (simplified version of generated by syzkaller) #include <pthread.h> #include <unistd.h> #include <sys/ptrace.h> #include <stdio.h> #include <signal.h> void *thread_func(void *arg) { ptrace(PTRACE_TRACEME, 0,0,0); return 0; } int main(void) { pthread_t thread; if (fork()) return 0; while (getppid() != 1) ; pthread_create(&thread, NULL, thread_func, NULL); pthread_join(thread, NULL); return 0; } creates an unreapable zombie if /sbin/init doesn't use __WALL. This is not a kernel bug, at least in a sense that everything works as expected: debugger should reap a traced sub-thread before it can reap the leader, but without __WALL/__WCLONE do_wait() ignores sub-threads. Unfortunately, it seems that /sbin/init in most (all?) distributions doesn't use it and we have to change the kernel to avoid the problem. Note also that most init's use sys_waitid() which doesn't allow __WALL, so the necessary user-space fix is not that trivial. This patch just adds the "ptrace" check into eligible_child(). To some degree this matches the "tsk->ptrace" in exit_notify(), ->exit_signal is mostly ignored when the tracee reports to debugger. Or WSTOPPED, the tracer doesn't need to set this flag to wait for the stopped tracee. This obviously means the user-visible change: __WCLONE and __WALL no longer have any meaning for debugger. And I can only hope that this won't break something, but at least strace/gdb won't suffer. We could make a more conservative change. Say, we can take __WCLONE into account, or !thread_group_leader(). But it would be nice to not complicate these historical/confusing checks. Signed-off-by:Dmitry Vyukov <dvyukov@google.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: <syzkaller@googlegroups.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Ryusuke Konishi authored
This fixes block comments with proper formatting to eliminate the following checkpatch.pl warnings: "WARNING: Block comments use * on subsequent lines" "WARNING: Block comments use a trailing */ on a separate line" Link: http://lkml.kernel.org/r/1462886671-3521-8-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by:
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Ryusuke Konishi authored
This fixes checkpatch.pl warning "WARNING: Single statement macros should not use a do {} while (0) loop". Link: http://lkml.kernel.org/r/1462886671-3521-7-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: -
Ryusuke Konishi authored
This fixes the checkpatch.pl warning that suggests else is not generally useful after a break or return. Link: http://lkml.kernel.org/r/1462886671-3521-6-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
This fixes checkpatch.pl warning "WARNING: Prefer 'unsigned int' to bare use of 'unsigned'". Link: http://lkml.kernel.org/r/1462886671-3521-5-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
This fixes checkpatch.pl warning "WARNING: suspect code indent for conditional statements". Link: http://lkml.kernel.org/r/1462886671-3521-4-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
This fixes the checkpatch.pl warning "WARNING: space prohibited before semicolon" at nilfs_store_magic_and_option(). Link: http://lkml.kernel.org/r/1462886671-3521-3-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
This updates call sites of nilfs_warning() and nilfs_error() so that they don't add a duplicate newline. These output functions are already designed to add a trailing newline to the message. Link: http://lkml.kernel.org/r/1462886671-3521-2-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
Remove trailing semicolons from macros, as suggested by checkpatch.pl. Link: http://lkml.kernel.org/r/1461935747-10380-12-git-send-email-konishi.ryusuke@lab.ntt.co.jp [konishi.ryusuke@lab.ntt.co.jp: fix style issues] Link: http://lkml.kernel.org/r/20160509.231703.1481729973362188932.konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
Clean up checkpatch.pl warnings "WARNING: Missing a blank line after declarations" from nilfs2. Link: http://lkml.kernel.org/r/1461935747-10380-11-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
This fixes the following checkpatch.pl warning: WARNING: __packed is preferred over __attribute__((packed)) #23: FILE: export.h:23: +} __attribute__ ((packed)); Link: http://lkml.kernel.org/r/1461935747-10380-10-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
Refactor nilfs_clear_inode() and nilfs_i_callback() so that cleanup code or resource deallocation related to metadata file will be moved out to mdt.c. Link: http://lkml.kernel.org/r/1461935747-10380-9-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
nilfs_mdt_mark_block_dirty() can be replaced with primary functions like nilfs_mdt_get_block() and mark_buffer_dirty(), and it's used only by nilfs_ioctl_mark_blocks_dirty(). This gets rid of the function to simplify the interface of metadata file. Link: http://lkml.kernel.org/r/1461935747-10380-8-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
To respond to a certain developer's request, this explicitly state that developers can reimplement the nilfs2 design for other operating systems to share data stored in that format. Link: http://lkml.kernel.org/r/1461935747-10380-7-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
Add nilfs.osdn.jp as the second web site of nilfs project. Link: http://lkml.kernel.org/r/1461935747-10380-6-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
E-mail addresses of osrg.net domain are no longer available. This removes them from authorship notices and prevents reporters from being confused. Link: http://lkml.kernel.org/r/1461935747-10380-5-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
This removes the extra paragraph which mentions FSF address in GPL notices from source code of nilfs2 and avoids the checkpatch.pl error related to it. Link: http://lkml.kernel.org/r/1461935747-10380-4-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
Fix checkpatch.pl error "ERROR: space prohibited before that ',' (ctx:WxW)" at nilfs_sufile_set_suinfo(). This also fixes checkpatch.pl warning "WARNING: Prefer 'unsigned int' to bare use of 'unsigned'" at nilfs_sufile_set_suinfo() and nilfs_sufile_get_suinfo(). Link: http://lkml.kernel.org/r/1461935747-10380-3-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
Fix the following checkpatch.pl error and warnings: ERROR: code indent should use tabs where possible #1317: FILE: super.c:1317: + ^I^Is_new = true;$ WARNING: please, no space before tabs #1317: FILE: super.c:1317: + ^I^Is_new = true;$ WARNING: please, no spaces at the start of a line #1317: FILE: super.c:1317: + ^I^Is_new = true;$ Link: http://lkml.kernel.org/r/1461935747-10380-2-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Julia Lawall authored
The nilfs_sc_operations structures are never modified, so declare them as const. Done with the help of Coccinelle. Signed-off-by:
Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by:
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Salah Triki authored
bh is reinitialized by sb_bread() so no need to init it with NULL in the beginning of befs_bread() Link: http://lkml.kernel.org/r/88481760b43226fac16adb1f1e68897e47d8235c.1462841692.git.salah.triki@acm.orgSigned-off-by:
Salah Triki <salah.triki@acm.org> Signed-off-by:
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Salah Triki authored
bh is reinitialized by sb_bread() so no need to init it with NULL in the beginning of befs_bread_iaddr() Link: http://lkml.kernel.org/r/586d2639d729345b9c07aac10ba713d8ceb8745a.1462841692.git.salah.triki@acm.orgSigned-off-by:
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Salah Triki authored
befs_ino is reinitialized by BEFS_I() so no need to init it with NULL in the beginning of befs_iget() Link: http://lkml.kernel.org/r/a5c02445e436629c4d4ba1b65d91501878942f58.1462842887.git.salah.triki@acm.orgSigned-off-by:
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Salah Triki authored
raw_inode is reinitialized to bh->b_data so no need to init it with NULL in the beginning of befs_iget() Link: http://lkml.kernel.org/r/0a66baaaacb6b7e5fcea5b31b57b649261152281.1462842887.git.salah.triki@acm.orgSigned-off-by:
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Salah Triki authored
bh is reinitialized by befs_bread() so no need to init it with NULL in the beginning of befs_iget() Link: http://lkml.kernel.org/r/38d62b1469bc3b316ba6b81fd8e26fc66fdd713b.1462842886.git.salah.triki@acm.orgSigned-off-by:
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Salah Triki authored
inode is reinitialized by befs_iget() so no need to init it with NULL in the beginning of befs_lookup() Link: http://lkml.kernel.org/r/03d7e46890aef94078130bed97c4f8f8ae9ea2b2.1462842886.git.salah.triki@acm.orgSigned-off-by:
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Salah Triki authored
iaddr_array is unconditionally initialized to NULL in befs_find_brun_dblindirect(). Link: http://lkml.kernel.org/r/940def273e30ef37957fba9da6981a10fb3c9741.1462649034.git.salah.triki@acm.orgSigned-off-by:
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Salah Triki authored
bh is reinitialized by befs_read_datastream() so no need to init it with NULL in the beginning of befs_read_lsymlink(). Link: http://lkml.kernel.org/r/e22f279bceb8d026af048952e02ba98925b21c92.1462649034.git.salah.triki@acm.orgSigned-off-by:
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Salah Triki authored
bh is reinitialized by befs_bread_iaddr() so no need to init it with NULL in the beginning of befs_read_datastream(). Link: http://lkml.kernel.org/r/81e1f70187db34d195c8e42b1ff78be6a71c0060.1462649034.git.salah.triki@acm.orgSigned-off-by:
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Vladimir Davydov authored
mem_cgroup_oom may be invoked multiple times while a process is handling a page fault, in which case current->memcg_in_oom will be overwritten leaking the previously taken css reference. Link: http://lkml.kernel.org/r/1464019330-7579-1-git-send-email-vdavydov@virtuozzo.comSigned-off-by:
Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
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Ralf Baechle authored
CONFIG_MIPS32_N32=y but CONFIG_BINFMT_ELF disabled results in the following linker errors: arch/mips/built-in.o: In function `elf_core_dump': binfmt_elfn32.c:(.text+0x23dbc): undefined reference to `elf_core_extra_phdrs' binfmt_elfn32.c:(.text+0x246e4): undefined reference to `elf_core_extra_data_size' binfmt_elfn32.c:(.text+0x248d0): undefined reference to `elf_core_write_extra_phdrs' binfmt_elfn32.c:(.text+0x24ac4): undefined reference to `elf_core_write_extra_data' CONFIG_MIPS32_O32=y but CONFIG_BINFMT_ELF disabled results in the following linker errors: arch/mips/built-in.o: In function `elf_core_dump': binfmt_elfo32.c:(.text+0x28a04): undefined reference to `elf_core_extra_phdrs' binfmt_elfo32.c:(.text+0x29330): undefined reference to `elf_core_extra_data_size' binfmt_elfo32.c:(.text+0x2951c): undefined reference to `elf_core_write_extra_phdrs' binfmt_elfo32.c:(.text+0x29710): undefined reference to `elf_core_write_extra_data' This is because binfmt_elfn32 and binfmt_elfo32 are using symbols from elfcore but for these configurations elfcore will not be built. Fixed by making elfcore selectable by a separate config symbol which unlike the current mechanism can also be used from other directories than kernel/, then having each flavor of ELF that relies on elfcore.o, select it in Kconfig, including CONFIG_MIPS32_N32 and CONFIG_MIPS32_O32 which fixes this issue. Link: http://lkml.kernel.org/r/20160520141705.GA1913@linux-mips.orgSigned-off-by:
Ralf Baechle <ralf@linux-mips.org> Reviewed-by:
James Hogan <james.hogan@imgtec.com> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Signed-off-by:
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