- 17 Jul, 2019 40 commits
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Arnd Bergmann authored
We exchange file timestamps with user space using psdev device read/write operations with a fixed but architecture specific binary layout. On 32-bit systems, this uses a 'timespec' structure that is defined by the C library to contain two 32-bit values for seconds and nanoseconds. As we get ready for the year 2038 overflow of the 32-bit signed seconds, the kernel now uses 64-bit timestamps internally, and user space will do the same change by changing the 'timespec' definition in the future. Unfortunately, this breaks the layout of the coda_vattr structure, so we need to redefine that in terms of something that does not change. I'm introducing a new 'struct vtimespec' structure here that keeps the existing layout, and the same change has to be done in the coda user space copy of linux/coda.h before anyone can use that on a 32-bit architecture with 64-bit time_t. An open question is what should happen to actual times past y2038, as they are now truncated to the last valid date when sent to user space, and interpreted as pre-1970 times when a timestamp with the MSB set is read back into the kernel. Alternatively, we could change the new timespec64_to_coda()/coda_to_timespec64() functions to use a different interpretation and extend the available range further to the future by disallowing past timestamps. This would require more changes in the user space side though. Link: http://lkml.kernel.org/r/562b7324149461743e4fbe2fedbf7c242f7e274a.1558117389.git.jaharkes@cs.cmu.edu Link: https://patchwork.kernel.org/patch/10474735/Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
Jan Harkes <jaharkes@cs.cmu.edu> Acked-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Colin Ian King authored
Trivial fix to clean up indentation, replace spaces with tab Link: http://lkml.kernel.org/r/ffc2bfa5a37ffcdf891c51b2e2ed618103965b24.1558117389.git.jaharkes@cs.cmu.eduSigned-off-by:
Colin Ian King <colin.king@canonical.com> Signed-off-by:
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Jan Harkes authored
These constants only used internally and not exposed to userspace. Link: http://lkml.kernel.org/r/baeafc30dad70d8b422ee679420099c2d8aa7da0.1558117389.git.jaharkes@cs.cmu.eduSigned-off-by:
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Jan Harkes authored
Probably safer to just show the unexpected length and debug it from the userspace side. Link: http://lkml.kernel.org/r/582ae759a4fdfa31a64c35de489fa4efabac09d6.1558117389.git.jaharkes@cs.cmu.eduSigned-off-by:
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Sam Protsenko authored
The kernel is self-contained project and can be built with bare-metal toolchain. But bare-metal toolchain doesn't define __linux__. Because of this u_quad_t type is not defined when using bare-metal toolchain and codafs build fails. This patch fixes it by defining u_quad_t type unconditionally. Link: http://lkml.kernel.org/r/3cbb40b0a57b6f9923a9d67b53473c0b691a3eaa.1558117389.git.jaharkes@cs.cmu.eduSigned-off-by:
Sam Protsenko <semen.protsenko@linaro.org> Signed-off-by:
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Jan Harkes authored
Add checks to make sure the downcall message we got from the Coda cache manager is large enough to contain the data it is supposed to have. i.e. when we get a CODA_ZAPDIR we can access &out->coda_zapdir.CodaFid. Link: http://lkml.kernel.org/r/894fb6b250add09e4e3935f14649f21284a5cb18.1558117389.git.jaharkes@cs.cmu.eduSigned-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Colin Ian King <colin.king@canonical.com> Cc: David Howells <dhowells@redhat.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Mikko Rapeli <mikko.rapeli@iki.fi> Cc: Sam Protsenko <semen.protsenko@linaro.org> Cc: Yann Droneaud <ydroneaud@opteya.com> Cc: Zhouyang Jia <jiazhouyang09@gmail.com> Signed-off-by:
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Zhouyang Jia authored
When fget fails, the lack of error-handling code may cause unexpected results. This patch adds error-handling code after calling fget. Link: http://lkml.kernel.org/r/2514ec03df9c33b86e56748513267a80dd8004d9.1558117389.git.jaharkes@cs.cmu.eduSigned-off-by:
Zhouyang Jia <jiazhouyang09@gmail.com> Signed-off-by:
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Mikko Rapeli authored
Only users of upc_req in kernel side fs/coda/psdev.c and fs/coda/upcall.c already include linux/coda_psdev.h. Suggested by Jan Harkes <jaharkes@cs.cmu.edu> in https://lore.kernel.org/lkml/20150531111913.GA23377@cs.cmu.edu/ Fixes these include/uapi/linux/coda_psdev.h compilation errors in userspace: linux/coda_psdev.h:12:19: error: field `uc_chain' has incomplete type struct list_head uc_chain; ^ linux/coda_psdev.h:13:2: error: unknown type name `caddr_t' caddr_t uc_data; ^ linux/coda_psdev.h:14:2: error: unknown type name `u_short' u_short uc_flags; ^ linux/coda_psdev.h:15:2: error: unknown type name `u_short' u_short uc_inSize; /* Size is at most 5000 bytes */ ^ linux/coda_psdev.h:16:2: error: unknown type name `u_short' u_short uc_outSize; ^ linux/coda_psdev.h:17:2: error: unknown type name `u_short' u_short uc_opcode; /* copied from data to save lookup */ ^ linux/coda_psdev.h:19:2: error: unknown type name `wait_queue_head_t' wait_queue_head_t uc_sleep; /* process' wait queue */ ^ Link: http://lkml.kernel.org/r/9f99f5ce6a0563d5266e6cf7aa9585aac2cae971.1558117389.git.jaharkes@cs.cmu.eduSigned-off-by:
Mikko Rapeli <mikko.rapeli@iki.fi> Signed-off-by:
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Mikko Rapeli authored
Part of a patch by Mikko Rapeli, as Arnd Bergman commented on the original patch. pid_t might differ between libc and the kernel, so the kernel interface has to use types that the kernel defines. Link: http://lkml.kernel.org/r/f374a71f4d351bc8c8b3ac18ad7765c88d806d10.1558117389.git.jaharkes@cs.cmu.eduSigned-off-by:
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Jan Harkes authored
Patch series "Coda updates". The following patch series is a collection of various fixes for Coda, most of which were collected from linux-fsdevel or linux-kernel but which have as yet not found their way upstream. This patch (of 22): Various file systems expect that vma->vm_file points at their own file handle, several use file_inode(vma->vm_file) to get at their inode or use vma->vm_file->private_data. However the way Coda wrapped mmap on a host file broke this assumption, vm_file was still pointing at the Coda file and the host file systems would scribble over Coda's inode and private file data. This patch fixes the incorrect expectation and wraps vm_ops->open and vm_ops->close to allow Coda to track when the vm_area_struct is destroyed so we still release the reference on the Coda file handle at the right time. Link: http://lkml.kernel.org/r/0e850c6e59c0b147dc2dcd51a3af004c948c3697.1558117389.git.jaharkes@cs.cmu.eduSigned-off-by:
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Anshuman Khandual authored
Architectures which support kprobes have very similar boilerplate around calling kprobe_fault_handler(). Use a helper function in kprobes.h to unify them, based on the x86 code. This changes the behaviour for other architectures when preemption is enabled. Previously, they would have disabled preemption while calling the kprobe handler. However, preemption would be disabled if this fault was due to a kprobe, so we know the fault was not due to a kprobe handler and can simply return failure. This behaviour was introduced in commit a980c0ef ("x86/kprobes: Refactor kprobes_fault() like kprobe_exceptions_notify()") [anshuman.khandual@arm.com: export kprobe_fault_handler()] Link: http://lkml.kernel.org/r/1561133358-8876-1-git-send-email-anshuman.khandual@arm.com Link: http://lkml.kernel.org/r/1560420444-25737-1-git-send-email-anshuman.khandual@arm.comSigned-off-by:
Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by:
Dave Hansen <dave.hansen@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: James Hogan <jhogan@kernel.org> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by:
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Kees Cook authored
This fixes a couple typos I noticed in the slab Kconfig: sacrifies -> sacrifices accellerate -> accelerate Seeing as no other instances of these typos are found elsewhere in the kernel and that I originally added one of the two, I can only assume working on slab must have caused damage to the spelling centers of my brain. Link: http://lkml.kernel.org/r/201905292203.CD000546EB@keescookSigned-off-by:
Kees Cook <keescook@chromium.org> Signed-off-by:
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Alexey Dobriyan authored
"passed_fileno" variable was deleted 11 years ago in 2.6.25. Link: http://lkml.kernel.org/r/20190529201747.GA23248@avx2 Fixes: d20894a2 ("Remove a.out interpreter support in ELF loader") Signed-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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YueHaibing authored
Fixes gcc '-Wunused-but-set-variable' warning: fs/binfmt_flat.c: In function load_flat_file: fs/binfmt_flat.c:419:16: warning: variable inode set but not used [-Wunused-but-set-variable] It's never used and can be removed. Link: http://lkml.kernel.org/r/20190525125341.9844-1-yuehaibing@huawei.comSigned-off-by:
YueHaibing <yuehaibing@huawei.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Matteo Croce authored
Commit d91bff3011cf ("proc/sysctl: add shared variables for range check") adds some shared const variables to be used instead of a local copy in each source file. Warn when a chunk duplicates one of these values in a ctl_table struct: $ scripts/checkpatch.pl 0001-test-commit.patch WARNING: duplicated sysctl range checking value 'zero', consider using the shared one in include/linux/sysctl.h #27: FILE: arch/arm/kernel/isa.c:48: + .extra1 = &zero, WARNING: duplicated sysctl range checking value 'int_max', consider using the shared one in include/linux/sysctl.h #28: FILE: arch/arm/kernel/isa.c:49: + .extra2 = &int_max, total: 0 errors, 2 warnings, 14 lines checked Link: http://lkml.kernel.org/r/20190531131422.14970-1-mcroce@redhat.comSigned-off-by:Matteo Croce <mcroce@redhat.com> Reviewed-by:
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Michel Lespinasse authored
As was already noted in rbtree.h, the logic to cache rb_first (or rb_last) can easily be implemented externally to the core rbtree api. Change the implementation to do just that. Previously the update of rb_leftmost was wired deeper into the implmentation, but there were some disadvantages to that - mostly, lib/rbtree.c had separate instantiations for rb_insert_color() vs rb_insert_color_cached(), as well as rb_erase() vs rb_erase_cached(), which were doing exactly the same thing save for the rb_leftmost update at the start of either function. text data bss dec hex filename 5405 120 0 5525 1595 lib/rbtree.o-vanilla 3827 96 0 3923 f53 lib/rbtree.o-patch [dave@stgolabs.net: changelog addition] Link: http://lkml.kernel.org/r/20190628171416.by5gdizl3rcxk5h5@linux-r8p5 [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20190628045008.39926-1-walken@google.comSigned-off-by:
Michel Lespinasse <walken@google.com> Acked-by:
Davidlohr Bueso <dbueso@suse.de> Acked-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by:
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Alexander Potapenko authored
Fix the following issues in test_meminit.c: - |size| in fill_with_garbage_skip() should be signed so that it doesn't overflow if it's not aligned on sizeof(*p); - fill_with_garbage_skip() should actually skip |skip| bytes; - do_kmem_cache_size() should deallocate memory in the RCU case. Link: http://lkml.kernel.org/r/20190626133135.217355-1-glider@google.com Fixes: 7e659650cbda ("lib: introduce test_meminit module") Fixes: 94e8988d91c7 ("lib/test_meminit.c: fix -Wmaybe-uninitialized false positive") Signed-off-by:
Alexander Potapenko <glider@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Kees Cook <keescook@chromium.org> Signed-off-by:
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Arnd Bergmann authored
The conditional logic is too complicated for the compiler to fully comprehend: lib/test_meminit.c: In function 'test_meminit_init': lib/test_meminit.c:236:5: error: 'buf_copy' may be used uninitialized in this function [-Werror=maybe-uninitialized] kfree(buf_copy); ^~~~~~~~~~~~~~~ lib/test_meminit.c:201:14: note: 'buf_copy' was declared here Simplify it by splitting out the non-rcu section. Link: http://lkml.kernel.org/r/20190617131210.2190280-1-arnd@arndb.de Fixes: af734ee6ec85 ("lib: introduce test_meminit module") Signed-off-by: -
Jonathan Corbet authored
Due to some sad limitations in how kerneldoc comments are parsed, the documentation in lib/string_helpers.c generates these warnings: lib/string_helpers.c:236: WARNING: Unexpected indentation. lib/string_helpers.c:241: WARNING: Block quote ends without a blank line; unexpected unindent. lib/string_helpers.c:446: WARNING: Unexpected indentation. lib/string_helpers.c:451: WARNING: Block quote ends without a blank line; unexpected unindent. lib/string_helpers.c:474: WARNING: Unexpected indentation. Rework the comments to obtain something like the desired result. Link: http://lkml.kernel.org/r/20190607110952.409011ba@lwn.netSigned-off-by:
Jonathan Corbet <corbet@lwn.net> Signed-off-by:
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Anshuman Khandual authored
Finish up what commit c2febafc ("mm: convert generic code to 5-level paging") started while levelling up P4D huge mapping support at par with PUD and PMD. A new arch call back arch_ioremap_p4d_supported() is added which just maintains status quo (P4D huge map not supported) on x86, arm64 and powerpc. When HAVE_ARCH_HUGE_VMAP is enabled its just a simple check from the arch about the support, hence runtime effects are minimal. Link: http://lkml.kernel.org/r/1561699231-20991-1-git-send-email-anshuman.khandual@arm.comSigned-off-by:
Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by:
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Anshuman Khandual authored
Virtual address alignment is essential in ensuring correct clearing for all intermediate level pgtable entries and freeing associated pgtable pages. An unaligned address can end up randomly freeing pgtable page that potentially still contains valid mappings. Hence also check it's alignment along with existing phys_addr check. Signed-off-by:
Catalin Marinas <catalin.marinas@arm.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Alexander Potapenko authored
Add tests for heap and pagealloc initialization. These can be used to check init_on_alloc and init_on_free implementations as well as other approaches to initialization. Expected test output in the case the kernel provides heap initialization (e.g. when running with either init_on_alloc=1 or init_on_free=1): test_meminit: all 10 tests in test_pages passed test_meminit: all 40 tests in test_kvmalloc passed test_meminit: all 60 tests in test_kmemcache passed test_meminit: all 10 tests in test_rcu_persistent passed test_meminit: all 120 tests passed! Link: http://lkml.kernel.org/r/20190529123812.43089-4-glider@google.comSigned-off-by:
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Kees Cook authored
This adds __GFP_NOWARN to the kmalloc()-portions of the overflow test to avoid tainting the kernel. Additionally fixes up the math on wrap size to be architecture and page size agnostic. Link: http://lkml.kernel.org/r/201905282012.0A8767E24@keescook Fixes: ca90800a ("test_overflow: Add memory allocation overflow tests") Signed-off-by:
Randy Dunlap <rdunlap@infradead.org> Suggested-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Joe Perches <joe@perches.com> Signed-off-by:
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Peter Rosin authored
Make sure that the trailing NUL is considered part of the string and can be found. Link: http://lkml.kernel.org/r/20190506124634.6807-4-peda@axentia.seSigned-off-by:
Peter Rosin <peda@axentia.se> Signed-off-by:
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Peter Rosin authored
If a memsetXX implementation is completely broken and fails in the first iteration, when i, j, and k are all zero, the failure is masked as zero is returned. Failing in the first iteration is perhaps the most likely failure, so this makes the tests pretty much useless. Avoid the situation by always setting a random unused bit in the result on failure. Link: http://lkml.kernel.org/r/20190506124634.6807-3-peda@axentia.se Fixes: 03270c13 ("lib/string.c: add testcases for memset16/32/64") Signed-off-by:
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Peter Rosin authored
Patch series "lib/string: search for NUL with strchr/strnchr". I noticed an inconsistency where strchr and strnchr do not behave the same with respect to the trailing NUL. strchr is standardised and the kernel function conforms, and the kernel relies on the behavior. So, naturally strchr stays as-is and strnchr is what I change. While writing a few tests to verify that my new strnchr loop was sane, I noticed that the tests for memset16/32/64 had a problem. Since it's all about the lib/string.c file I made a short series of it all... This patch (of 3): strchr considers the terminating NUL to be part of the string, and NUL can thus be searched for with that function. For consistency, do the same with strnchr. Link: http://lkml.kernel.org/r/20190506124634.6807-2-peda@axentia.seSigned-off-by:
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Alexey Dobriyan authored
list_del() poisoning can generate 2 64-bit immediate loads but it also can generate one 64-bit immediate load and an addition: 48 b8 00 01 00 00 00 00 ad de movabs rax,0xdead000000000100 48 89 47 58 mov QWORD PTR [rdi+0x58],rax 48 05 00 01 00 00 <=====> add rax,0x100 48 89 47 60 mov QWORD PTR [rdi+0x60],rax However on x86_64 not all constants are equal: those within [-128, 127] range can be added with shorter "add r64, imm32" instruction: 48 b8 00 01 00 00 00 00 ad de movabs rax,0xdead000000000100 48 89 47 58 mov QWORD PTR [rdi+0x58],rax 48 83 c0 22 <======> add rax,0x22 48 89 47 60 mov QWORD PTR [rdi+0x60],rax Patch saves 2 bytes per some LIST_POISON2 usage. (Slightly disappointing) space savings on F29 x86_64 config: add/remove: 0/0 grow/shrink: 0/2164 up/down: 0/-5184 (-5184) Function old new delta zstd_get_workspace 548 546 -2 ... mlx4_delete_all_resources_for_slave 4826 4804 -22 Total: Before=83304131, After=83298947, chg -0.01% New constants are: 0xdead000000000100 0xdead000000000122 Note: LIST_POISON1 can't be changed to ...11 because something in page allocator requires low bit unset. Link: http://lkml.kernel.org/r/20190513191502.GA8492@avx2Signed-off-by:
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Joe Perches authored
Add a command line switch --no-moderated to skip L: mailing lists marked with 'moderated'. Some people prefer not emailing moderated mailing lists as the moderation time can be indeterminate and some emails can be intentionally dropped by a moderator. This can cause fragmentation of email threads when some are subscribed to a moderated list but others are not and emails are dropped. Link: http://lkml.kernel.org/r/6f23c2918ad9fc744269feb8f909bdfb105c5afc.camel@perches.comSigned-off-by:
Joe Perches <joe@perches.com> Tested-by:
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Qian Cai authored
Fix this compilation warning on x86 by making flush_cache_vmap() inline. lib/ioremap.c: In function 'ioremap_page_range': lib/ioremap.c:214:16: warning: variable 'start' set but not used [-Wunused-but-set-variable] unsigned long start; ^~~~~ While at it, convert all other similar functions to inline for consistency. Link: http://lkml.kernel.org/r/1562594592-15228-1-git-send-email-cai@lca.pwSigned-off-by:Qian Cai <cai@lca.pw> Reviewed-by:
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Stephen Kitt authored
isa_page_to_bus() is deprecated and is no longer used anywhere. Remove it entirely. Link: http://lkml.kernel.org/r/20190613161155.16946-1-steve@sk2.orgSigned-off-by:
Stephen Kitt <steve@sk2.org> Acked-by:
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Masahiro Yamada authored
Now that BIT() can be used from assembly code, we can safely replace _BITUL() with equivalent BIT(). UAPI headers are still required to use _BITUL(), but there is no more reason to use it in kernel headers. BIT() is shorter. Link: http://lkml.kernel.org/r/20190609153941.17249-2-yamada.masahiro@socionext.comSigned-off-by:
Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by:
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Masahiro Yamada authored
BIT(), GENMASK(), etc. are useful to define register bits of hardware. However, low-level code is often written in assembly, where they are not available due to the hard-coded 1UL, 0UL. In fact, in-kernel headers such as arch/arm64/include/asm/sysreg.h use _BITUL() instead of BIT() so that the register bit macros are available in assembly. Using macros in include/uapi/linux/const.h have two reasons: [1] For use in uapi headers We should use underscore-prefixed variants for user-space. [2] For use in assembly code Since _BITUL() uses UL(1) instead of 1UL, it can be used as an alternative of BIT(). For [2], it is pretty easy to change BIT() etc. for use in assembly. This allows to replace _BUTUL() in kernel-space headers with BIT(). Link: http://lkml.kernel.org/r/20190609153941.17249-1-yamada.masahiro@socionext.comSigned-off-by:
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Weitao Hou authored
fix lenght to length Link: http://lkml.kernel.org/r/20190521050937.4370-1-houweitaoo@gmail.comSigned-off-by:
Weitao Hou <houweitaoo@gmail.com> Acked-by:
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Radoslaw Burny authored
Normally, the inode's i_uid/i_gid are translated relative to s_user_ns, but this is not a correct behavior for proc. Since sysctl permission check in test_perm is done against GLOBAL_ROOT_[UG]ID, it makes more sense to use these values in u_[ug]id of proc inodes. In other words: although uid/gid in the inode is not read during test_perm, the inode logically belongs to the root of the namespace. I have confirmed this with Eric Biederman at LPC and in this thread: https://lore.kernel.org/lkml/87k1kzjdff.fsf@xmission.com Consequences ============ Since the i_[ug]id values of proc nodes are not used for permissions checks, this change usually makes no functional difference. However, it causes an issue in a setup where: * a namespace container is created without root user in container - hence the i_[ug]id of proc nodes are set to INVALID_[UG]ID * container creator tries to configure it by writing /proc/sys files, e.g. writing /proc/sys/kernel/shmmax to configure shared memory limit Kernel does not allow to open an inode for writing if its i_[ug]id are invalid, making it impossible to write shmmax and thus - configure the container. Using a container with no root mapping is apparently rare, but we do use this configuration at Google. Also, we use a generic tool to configure the container limits, and the inability to write any of them causes a failure. History ======= The invalid uids/gids in inodes first appeared due to 81754357 (fs: Update i_[ug]id_(read|write) to translate relative to s_user_ns). However, AFAIK, this did not immediately cause any issues. The inability to write to these "invalid" inodes was only caused by a later commit 0bd23d09 (vfs: Don't modify inodes with a uid or gid unknown to the vfs). Tested: Used a repro program that creates a user namespace without any mapping and stat'ed /proc/$PID/root/proc/sys/kernel/shmmax from outside. Before the change, it shows the overflow uid, with the change it's 0. The overflow uid indicates that the uid in the inode is not correct and thus it is not possible to open the file for writing. Link: http://lkml.kernel.org/r/20190708115130.250149-1-rburny@google.com Fixes: 0bd23d09 ("vfs: Don't modify inodes with a uid or gid unknown to the vfs") Signed-off-by:
Radoslaw Burny <rburny@google.com> Acked-by:
Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: John Sperbeck <jsperbeck@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by:
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Alexey Dobriyan authored
I thought that /proc/sysvipc has the same bug as /proc/net commit 1fde6f21 proc: fix /proc/net/* after setns(2) However, it doesn't! /proc/sysvipc files do get_ipc_ns(current->nsproxy->ipc_ns); in their open() hook and avoid the problem. Keep the test, maybe /proc/sysvipc will become broken someday :-\ Link: http://lkml.kernel.org/r/20190706180146.GA21015@avx2Signed-off-by:
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Alexey Dobriyan authored
Don't repeat function signatures twice. This is a kind-of-precursor for "struct proc_ops". Note: typeof(pde->proc_fops->...) ...; can't be used because ->proc_fops is "const struct file_operations *". "const" prevents assignment down the code and it can't be deleted in the type system. Link: http://lkml.kernel.org/r/20190529191110.GB5703@avx2Signed-off-by:
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Alexey Dobriyan authored
Add typeof_member() macro so that types can be extracted without introducing dummy variables. Link: http://lkml.kernel.org/r/20190529190720.GA5703@avx2Signed-off-by:
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Kairui Song authored
Since commit 2724273e ("vmcore: add API to collect hardware dump in second kernel"), drivers are allowed to add device related dump data to vmcore as they want by using the device dump API. This has a potential issue, the data is stored in memory, drivers may append too much data and use too much memory. The vmcore is typically used in a kdump kernel which runs in a pre-reserved small chunk of memory. So as a result it will make kdump unusable at all due to OOM issues. So introduce new 'novmcoredd' command line option. User can disable device dump to reduce memory usage. This is helpful if device dump is using too much memory, disabling device dump could make sure a regular vmcore without device dump data is still available. [akpm@linux-foundation.org: tweak documentation] [akpm@linux-foundation.org: vmcore.c needs moduleparam.h] Link: http://lkml.kernel.org/r/20190528111856.7276-1-kasong@redhat.comSigned-off-by:
Kairui Song <kasong@redhat.com> Acked-by:
Dave Young <dyoung@redhat.com> Reviewed-by:
Bhupesh Sharma <bhsharma@redhat.com> Cc: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com> Cc: "David S . Miller" <davem@davemloft.net> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by:
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Alexey Dobriyan authored
Test tries to access vsyscall page and if it doesn't exist gets SIGSEGV which can spam into dmesg. However the segfault happens by design. Handle it and carry information via exit code to parent. Link: http://lkml.kernel.org/r/20190524181256.GA2260@avx2Signed-off-by:
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Christoph Hellwig authored
The whole header file deals with swap entries and PTEs, none of which can exist for nommu builds. The current nommu ports have lots of stubs to allow the inline functions in swapops.h to compile, but as none of this functionality is actually used there is no point in even providing it. This way we don't have to provide the stubs for the upcoming RISC-V nommu port, and can eventually remove it from the existing ports. Link: http://lkml.kernel.org/r/20190703122359.18200-4-hch@lst.deSigned-off-by:
Christoph Hellwig <hch@lst.de> Cc: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by:
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