- 21 Jan, 2016 40 commits
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Kees Cook authored
SYSCTL_WRITES_WARN was added in commit f4aacea2 ("sysctl: allow for strict write position handling"), and released in v3.16 in August of 2014. Since then I can find only 1 instance of non-zero offset writing[1], and it was fixed immediately in CRIU[2]. As such, it appears safe to flip this to the strict state now. [1] https://www.google.com/search?q="when%20file%20position%20was%20not%200" [2] http://lists.openvz.org/pipermail/criu/2015-April/019819.htmlSigned-off-by:
Kees Cook <keescook@chromium.org> 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>
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Davidlohr Bueso authored
With commit d72da4a4 ("rbtree: Make lockless searches non-fatal") our rbtrees provide weak guarantees that allows us to do lockless (and very speculative) reads of the tree. Such readers cannot see partial stores on nodes, ie left/right as well as root. As such, similar to the WRITE_ONCE semantics when doing rotations, use READ_ONCE when checking the root node in RB_EMPTY_ROOT. Signed-off-by:
Davidlohr Bueso <dbueso@suse.de> Acked-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Michel Lespinasse <walken@google.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by:
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Geliang Tang authored
Use kobj_to_dev() instead of open-coding it. Signed-off-by:
Geliang Tang <geliangtang@163.com> Acked-by:
"Bounine, Alexandre" <Alexandre.Bounine@idt.com> Signed-off-by:
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Xunlei Pang authored
Move the stuff currently only used by the kexec file code within CONFIG_KEXEC_FILE (and CONFIG_KEXEC_VERIFY_SIG). Also move internal "struct kexec_sha_region" and "struct kexec_buf" into "kexec_internal.h". Signed-off-by:
Xunlei Pang <xlpang@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dave Young <dyoung@redhat.com> Signed-off-by:
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Geliang Tang authored
Use list_for_each_entry_safe() instead of list_for_each_safe() to simplify the code. Signed-off-by:
Baoquan He <bhe@redhat.com> Signed-off-by:
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Xunlei Pang authored
sanity_check_segment_list() checks KEXEC_TYPE_CRASH flag to ensure all the segments of the loaded crash kernel are within the kernel crash resource limits, so set the flag beforehand. Signed-off-by:
Dave Young <dyoung@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Acked-by:
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Rasmus Villemoes authored
Almost all callers of the set_cpu_* functions pass an explicit true or false. Making them static inline thus replaces the function calls with a simple set_bit/clear_bit, saving some .text. Signed-off-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by:
Rusty Russell <rusty@rustcorp.com.au> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
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Rasmus Villemoes authored
Replace the variables cpu_possible_mask, cpu_online_mask, cpu_present_mask and cpu_active_mask with macros expanding to expressions of the same type and value, eliminating some indirection. Signed-off-by:
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Rasmus Villemoes authored
The only user of the lvalue-ness of the cpu_*_mask variables is in drivers/base/cpu.c, and that is mostly a work-around for the fact that not even const variables can be used in static initialization. Now that the underlying struct cpumasks are exposed we can take their address. Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
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Rasmus Villemoes authored
Exporting the cpumasks __cpu_possible_mask and friends will allow us to remove the extra indirection through the cpu_*_mask variables. It will also allow the set_cpu_* functions to become static inlines, which will give a .text reduction. Signed-off-by:
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Rasmus Villemoes authored
Change cpu_possible_bits and friends (online, present, active) from being bitmaps that happen to have the right size to actually being struct cpumasks. Also rename them to __cpu_xyz_mask. This is mostly a small cleanup in preparation for exporting them and, eventually, eliminating the extra indirection through the cpu_xyz_mask variables. Signed-off-by:
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Rasmus Villemoes authored
The four cpumasks cpu_{possible,online,present,active}_bits are exposed readonly via the corresponding const variables cpu_xyz_mask. But they are also accessible for arbitrary writing via the exposed functions set_cpu_xyz. There's quite a bit of code throughout the kernel which iterates over or otherwise accesses these bitmaps, and having the access go via the cpu_xyz_mask variables is nowadays [1] simply a useless indirection. It may be that any problem in CS can be solved by an extra level of indirection, but that doesn't mean every extra indirection solves a problem. In this case, it even necessitates some minor ugliness (see 4/6). Patch 1/6 is new in v2, and fixes a build failure on ppc by renaming a struct member, to avoid problems when the identifier cpu_online_mask becomes a macro later in the series. The next four patches eliminate the cpu_xyz_mask variables by simply exposing the actual bitmaps, after renaming them to discourage direct access - that still happens through cpu_xyz_mask, which are now simply macros with the same type and value as they used to have. After that, there's no longer any reason to have the setter functions be out-of-line: The boolean parameter is almost always a literal true or false, so by making them static inlines they will usually compile to one or two instructions. For a defconfig build on x86_64, bloat-o-meter says we save ~3000 bytes. We also save a little stack (stackdelta says 127 functions have a 16 byte smaller stack frame, while two grow by that amount). Mostly because, when iterating over the mask, gcc typically loads the value of cpu_xyz_mask into a callee-saved register and from there into %rdi before each find_next_bit call - now it can just load the appropriate immediate address into %rdi before each call. [1] See Rusty's kind explanation http://thread.gmane.org/gmane.linux.kernel/2047078/focus=2047722 for some historic context. This patch (of 6): As preparation for eliminating the indirect access to the various global cpu_*_bits bitmaps via the pointer variables cpu_*_mask, rename the cpu_online_mask member of struct fadump_crash_info_header to simply online_mask, thus allowing cpu_online_mask to become a macro. Signed-off-by:Michael Ellerman <mpe@ellerman.id.au> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by:
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Dmitry Safonov authored
Signed-off-by:
Dmitry Safonov <0x7f454c46@gmail.com> Signed-off-by:
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Jann Horn authored
Let %h and %e print empty values as "!", "." as "!" and ".." as "!.". This prevents hostnames and comm values that are empty or consist of one or two dots from changing the directory level at which the corefile will be stored. Consider the case where someone decides to sort coredumps by hostname with a core pattern like "/cores/%h/core.%e.%p.%t" or so. In this case, hostnames "" and "." would cause the coredump to land directly in /cores, which is not what the intent behind the core pattern is, and ".." would cause the coredump to land in /. Yeah, there probably aren't many people who do that, but I still don't want this edgecase to be kind of broken. It seems very unlikely that this caused security issues anywhere, so I'm not requesting a stable backport. [akpm@linux-foundation.org: tweak code comment] Signed-off-by:
Jann Horn <jann@thejh.net> Acked-by:
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Jann Horn authored
By checking the effective credentials instead of the real UID / permitted capabilities, ensure that the calling process actually intended to use its credentials. To ensure that all ptrace checks use the correct caller credentials (e.g. in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS flag), use two new flags and require one of them to be set. The problem was that when a privileged task had temporarily dropped its privileges, e.g. by calling setreuid(0, user_uid), with the intent to perform following syscalls with the credentials of a user, it still passed ptrace access checks that the user would not be able to pass. While an attacker should not be able to convince the privileged task to perform a ptrace() syscall, this is a problem because the ptrace access check is reused for things in procfs. In particular, the following somewhat interesting procfs entries only rely on ptrace access checks: /proc/$pid/stat - uses the check for determining whether pointers should be visible, useful for bypassing ASLR /proc/$pid/maps - also useful for bypassing ASLR /proc/$pid/cwd - useful for gaining access to restricted directories that contain files with lax permissions, e.g. in this scenario: lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar drwx------ root root /root drwxr-xr-x root root /root/foobar -rw-r--r-- root root /root/foobar/secret Therefore, on a system where a root-owned mode 6755 binary changes its effective credentials as described and then dumps a user-specified file, this could be used by an attacker to reveal the memory layout of root's processes or reveal the contents of files he is not allowed to access (through /proc/$pid/cwd). [akpm@linux-foundation.org: fix warning] Signed-off-by: -
Jann Horn authored
It looks like smack and yama weren't aware that the ptrace mode can have flags ORed into it - PTRACE_MODE_NOAUDIT until now, but only for /proc/$pid/stat, and with the PTRACE_MODE_*CREDS patch, all modes have flags ORed into them. Signed-off-by:
Casey Schaufler <casey@schaufler-ca.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by:
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Oleg Nesterov authored
task_stopped_code()->task_is_stopped_or_traced() doesn't look right, the traced task must never be TASK_STOPPED. We can not add WARN_ON(task_is_stopped(p)), but this is only because do_wait() can race with PTRACE_ATTACH from another thread. [akpm@linux-foundation.org: teeny cleanup] Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Roland McGrath <roland@hack.frob.com> Acked-by:
Tejun Heo <tj@kernel.org> Cc: Pedro Alves <palves@redhat.com> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Signed-off-by:
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Oleg Nesterov authored
ptrace_attach() can hang waiting for STOPPED -> TRACED transition if the tracee gets frozen in between, change wait_on_bit() to use TASK_KILLABLE. This doesn't really solve the problem(s) and we probably need to fix the freezer. In particular, note that this means that pm freezer will fail if it races attach-to-stopped-task. And otoh perhaps we can just remove JOBCTL_TRAPPING_BIT altogether, it is not clear if we really need to hide this transition from debugger, WNOHANG after PTRACE_ATTACH can fail anyway if it races with SIGCONT. Signed-off-by:
Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Roland McGrath <roland@hack.frob.com> Acked-by:
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Julia Lawall authored
The fatent_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> Acked-by:
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by:
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Namjae Jeon authored
Update the limitation for fat fallocate. Signed-off-by:
Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by:
Amit Sahrawat <a.sahrawat@samsung.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by:
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Namjae Jeon authored
Make the fibmap call return the proper physical block number for any offset request in the fallocated range. Signed-off-by:
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Namjae Jeon authored
Skip new cluster allocation after checking i_blocks limit in _fat_get_block, because the blocks are already allocated in fallocated region. Signed-off-by:
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Namjae Jeon authored
Implement preallocation via the fallocate syscall on VFAT partitions. This patch is based on an earlier patch of the same name which had some issues detailed below and did not get accepted. Refer https://lkml.org/lkml/2007/12/22/130. a) The preallocated space was not persistent when the FALLOC_FL_KEEP_SIZE flag was set. It will deallocate cluster at evict time. b) There was no need to zero out the clusters when the flag was set Instead of doing an expanding truncate, just allocate clusters and add them to the fat chain. This reduces preallocation time. Compatibility with windows: There are no issues when FALLOC_FL_KEEP_SIZE is not set because it just does an expanding truncate. Thus reading from the preallocated area on windows returns null until data is written to it. When a file with preallocated area using the FALLOC_FL_KEEP_SIZE was written to on windows, the windows driver freed-up the preallocated clusters and allocated new clusters for the new data. The freed up clusters gets reflected in the free space available for the partition which can be seen from the Volume properties. The windows chkdsk tool also does not report any errors on a disk containing files with preallocated space. And there is also no issue using linux fat fsck. because discard preallocated clusters at repair time. Signed-off-by:
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OGAWA Hirofumi authored
This detects simple corruption cases of directory, and tries to avoid further damage to user data. And performance impact of this validation should be very low, or not measurable. Signed-off-by:
Vegard Nossum <vegard.nossum@oracle.com> Tested-by:
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Jan Kara authored
Currently we limit values of time_offset mount option to be between -12 and 12 hours. However e.g. zone GMT+12 can have a DST correction on top which makes the total time difference 13 hours. Update the checks in mount option parsing to allow offset of upto 24 hours to allow for unusual cases. Signed-off-by:
Jan Kara <jack@suse.cz> Reported-by:
Volker Kuhlmann <list0570@paradise.net.nz> Acked-by:
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Geliang Tang authored
Use list_for_each_entry() instead of list_for_each() to simplify the code. Signed-off-by:
Vyacheslav Dubeyko <slava@dubeyko.com> Signed-off-by:
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Yaowei Bai authored
Make initrd_load() return bool due to this particular function only using either one or zero as its return value. No functional change. Signed-off-by:
Yaowei Bai <baiyaowei@cmss.chinamobile.com> Signed-off-by:
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Yaowei Bai authored
Make obsolete_checksetup() return bool due to this particular function only using either one or zero as its return value. No functional change. Signed-off-by:
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Jason Baron authored
Currently, epoll file descriptors or epfds (the fd returned from epoll_create[1]()) that are added to a shared wakeup source are always added in a non-exclusive manner. This means that when we have multiple epfds attached to a shared fd source they are all woken up. This creates thundering herd type behavior. Introduce a new 'EPOLLEXCLUSIVE' flag that can be passed as part of the 'event' argument during an epoll_ctl() EPOLL_CTL_ADD operation. This new flag allows for exclusive wakeups when there are multiple epfds attached to a shared fd event source. The implementation walks the list of exclusive waiters, and queues an event to each epfd, until it finds the first waiter that has threads blocked on it via epoll_wait(). The idea is to search for threads which are idle and ready to process the wakeup events. Thus, we queue an event to at least 1 epfd, but may still potentially queue an event to all epfds that are attached to the shared fd source. Performance testing was done by Madars Vitolins using a modified version of Enduro/X. The use of the 'EPOLLEXCLUSIVE' flag reduce the length of this particular workload from 860s down to 24s. Sample epoll_clt text: EPOLLEXCLUSIVE Sets an exclusive wakeup mode for the epfd file descriptor that is being attached to the target file descriptor, fd. Thus, when an event occurs and multiple epfd file descriptors are attached to the same target file using EPOLLEXCLUSIVE, one or more epfds will receive an event with epoll_wait(2). The default in this scenario (when EPOLLEXCLUSIVE is not set) is for all epfds to receive an event. EPOLLEXCLUSIVE may only be specified with the op EPOLL_CTL_ADD. Signed-off-by:
Jason Baron <jbaron@akamai.com> Tested-by:
Madars Vitolins <m@silodev.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Eric Wong <normalperson@yhbt.net> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by:
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Vladimir Zapolskiy authored
A simple search over the kernel souce displays a number of correctly defined multiline macro, which generally are used as an array element initializer: % find ../linux -type f | xargs grep -B1 -H '^[:space]*\[.*\\$' However checkpatch.pl unexpectedly complains about all these macro definitions: % ./scripts/checkpatch.pl --types COMPLEX_MACRO -f include/linux/perf/arm_pmu.h ERROR: Macros with complex values should be enclosed in parentheses +#define PERF_MAP_ALL_UNSUPPORTED \ + [0 ... PERF_COUNT_HW_MAX - 1] = HW_OP_UNSUPPORTED The change intends to fix this type of false positives by flattening only array members and skipping array element designators. Signed-off-by:
Vladimir Zapolskiy <vz@mleia.com> Acked-by:
Joe Perches <joe@perches.com> Cc: Andy Whitcroft <apw@canonical.com> Signed-off-by:
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Joe Perches authored
The current test excludes any macro with ## concatenation from being reported with hidden flow control. Some macros are used with return or goto statements along with ##args or ##__VA_ARGS__. A somewhat common case is a logging macro like pr_info(fmt, ...) then a return or goto statement. Check the concatenated variable for args or __VA_ARGS__ and allow those macros to also be reported when they contain a return or goto. Signed-off-by:
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Joe Perches authored
Linus Torvalds wrote: > I can't but help to react that this: > #define IOMMU_ERROR_CODE (~(unsigned long) 0) > Not that this *matters*, but it's a bit odd to have to cast constants > to perfectly regular C types. So add a test that looks for constants that are cast to standard C90 int or longer types and suggest using C90 "6.4.4.1 Integer constants" integer-suffixes instead. Miscellanea: o Add a --fix option too Signed-off-by:
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Chris Metcalf authored
The clz table (__clz_tab) in lib/clz_tab.c is also provided as part of libgcc.a, and many architectures link against libgcc. To allow the linker to avoid a multiple-definition link failure, clz_tab.o has to be in lib/lib.a rather than lib/builtin.o. The specific issue is that libgcc.a comes before lib/builtin.o on vmlinux.o's link command line, so its _clz.o is pulled to satisfy __clz_tab, and then when the remainder of lib/builtin.o is pulled in to satisfy all the other dependencies, the __clz_tab symbols conflict. By putting clz_tab.o in lib.a, the linker can simply avoid pulling it into vmlinux.o when this situation arises. The definitions of __clz_tab are the same in libgcc.a and in the kernel; arguably we could also simply rename the kernel version, but it's unlikely the libgcc version will ever change to become incompatible, so just using it seems reasonably safe. Signed-off-by:
Chris Metcalf <cmetcalf@ezchip.com> Acked-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
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Adam Barth authored
This text refers to the "first 7 functions", which was correct when written but became incorrect when Johannes Weiner added another function to the list in 139e5616 ("lib: radix_tree: tree node interface"). Change the text to correctly refer to the first 8 functions. Signed-off-by:
Adam Barth <aurorean@gmail.com> Signed-off-by:
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Andy Shevchenko authored
Like others test are doing print the gathered statistics after test module is finished. Return from the module based on the result. Signed-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by:
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Andy Shevchenko authored
Currently the only one combination is tested for overflow, i.e. rowsize = 16, groupsize = 1, len = 1. Do various test to go through all possible branches. Signed-off-by:
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Andy Shevchenko authored
After processing by hex_dump_to_buffer() check all the parts to be expected. Part 1. The actual expected hex dump with or without ASCII part. Part 2. Check if the buffer is dirty beyond needed. Part 3. Return code should be as expected. This is done by using comparison of the return code and memcmp() against the test buffer. We fill the buffer by FILL_CHAR ('#') characters, so, we expect to have a tail of the buffer will be left untouched. The terminating NUL is also checked by memcmp(). Signed-off-by: -
Andy Shevchenko authored
Better to use memcmp() against entire buffer to check that nothing is happened to the data in the tail. Signed-off-by:
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Andy Shevchenko authored
The magic numbers of the length are converted to their actual meaning, such as end of the buffer with and without ASCII part. We don't touch the rest of the magic constants that will be removed in the following commits. Signed-off-by:
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Andy Shevchenko authored
When test for overflow do iterate the buffer length in a range 0 .. BUF_SIZE. Signed-off-by:
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