- 09 1月, 2019 4 次提交
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由 Kees Cook 提交于
Until now, any LSM without an enable storage variable was considered enabled. This inverts the logic and sets defaults to true only if the LSM gets added to the ordered initialization list. (And an exception continues for the major LSMs until they are integrated into the ordered initialization in a later patch.) Signed-off-by: NKees Cook <keescook@chromium.org>
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由 Kees Cook 提交于
As a prerequisite to adjusting LSM selection logic in the future, this moves the selection logic up out of the individual major LSMs, making their init functions only run when actually enabled. This considers all LSMs enabled by default unless they specified an external "enable" variable. Signed-off-by: NKees Cook <keescook@chromium.org> Reviewed-by: NCasey Schaufler <casey@schaufler-ca.com> Reviewed-by: NJohn Johansen <john.johansen@canonical.com>
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由 Kees Cook 提交于
In preparation for lifting the "is this LSM enabled?" logic out of the individual LSMs, pass in any special enabled state tracking (as needed for SELinux, AppArmor, and LoadPin). This should be an "int" to include handling any future cases where "enabled" is exposed via sysctl which has no "bool" type. Signed-off-by: NKees Cook <keescook@chromium.org> Reviewed-by: NCasey Schaufler <casey@schaufler-ca.com> Reviewed-by: NJohn Johansen <john.johansen@canonical.com>
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由 Kees Cook 提交于
This adds a flag for the current "major" LSMs to distinguish them when we have a universal method for ordering all LSMs. It's called "legacy" since the distinction of "major" will go away in the blob-sharing world. Signed-off-by: NKees Cook <keescook@chromium.org> Reviewed-by: NCasey Schaufler <casey@schaufler-ca.com> Reviewed-by: NJohn Johansen <john.johansen@canonical.com>
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- 06 1月, 2019 3 次提交
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由 Eric Biggers 提交于
Add support for the Adiantum encryption mode to fscrypt. Adiantum is a tweakable, length-preserving encryption mode with security provably reducible to that of XChaCha12 and AES-256, subject to a security bound. It's also a true wide-block mode, unlike XTS. See the paper "Adiantum: length-preserving encryption for entry-level processors" (https://eprint.iacr.org/2018/720.pdf) for more details. Also see commit 059c2a4d ("crypto: adiantum - add Adiantum support"). On sufficiently long messages, Adiantum's bottlenecks are XChaCha12 and the NH hash function. These algorithms are fast even on processors without dedicated crypto instructions. Adiantum makes it feasible to enable storage encryption on low-end mobile devices that lack AES instructions; currently such devices are unencrypted. On ARM Cortex-A7, on 4096-byte messages Adiantum encryption is about 4 times faster than AES-256-XTS encryption; decryption is about 5 times faster. In fscrypt, Adiantum is suitable for encrypting both file contents and names. With filenames, it fixes a known weakness: when two filenames in a directory share a common prefix of >= 16 bytes, with CTS-CBC their encrypted filenames share a common prefix too, leaking information. Adiantum does not have this problem. Since Adiantum also accepts long tweaks (IVs), it's also safe to use the master key directly for Adiantum encryption rather than deriving per-file keys, provided that the per-file nonce is included in the IVs and the master key isn't used for any other encryption mode. This configuration saves memory and improves performance. A new fscrypt policy flag is added to allow users to opt-in to this configuration. Signed-off-by: NEric Biggers <ebiggers@google.com> Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
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由 Masahiro Yamada 提交于
These comments are leftovers of commit fcc8487d ("uapi: export all headers under uapi directories"). Prior to that commit, exported headers must be explicitly added to header-y. Now, all headers under the uapi/ directories are exported. Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
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由 Masahiro Yamada 提交于
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: NSedat Dilek <sedat.dilek@gmail.com>
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- 05 1月, 2019 16 次提交
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由 Nikolay Borisov 提交于
Multiple filesystems open code lru_to_page(). Rectify this by moving the macro from mm_inline (which is specific to lru stuff) to the more generic mm.h header and start using the macro where appropriate. No functional changes. Link: http://lkml.kernel.org/r/20181129104810.23361-1-nborisov@suse.com Link: https://lkml.kernel.org/r/20181129075301.29087-1-nborisov@suse.comSigned-off-by: NNikolay Borisov <nborisov@suse.com> Acked-by: NMichal Hocko <mhocko@suse.com> Reviewed-by: NDavid Hildenbrand <david@redhat.com> Reviewed-by: NMike Rapoport <rppt@linux.ibm.com> Acked-by: NPankaj gupta <pagupta@redhat.com> Acked-by: "Yan, Zheng" <zyan@redhat.com> [ceph] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Joel Fernandes (Google) 提交于
Patch series "Add support for fast mremap". This series speeds up the mremap(2) syscall by copying page tables at the PMD level even for non-THP systems. There is concern that the extra 'address' argument that mremap passes to pte_alloc may do something subtle architecture related in the future that may make the scheme not work. Also we find that there is no point in passing the 'address' to pte_alloc since its unused. This patch therefore removes this argument tree-wide resulting in a nice negative diff as well. Also ensuring along the way that the enabled architectures do not do anything funky with the 'address' argument that goes unnoticed by the optimization. Build and boot tested on x86-64. Build tested on arm64. The config enablement patch for arm64 will be posted in the future after more testing. The changes were obtained by applying the following Coccinelle script. (thanks Julia for answering all Coccinelle questions!). Following fix ups were done manually: * Removal of address argument from pte_fragment_alloc * Removal of pte_alloc_one_fast definitions from m68k and microblaze. // Options: --include-headers --no-includes // Note: I split the 'identifier fn' line, so if you are manually // running it, please unsplit it so it runs for you. virtual patch @pte_alloc_func_def depends on patch exists@ identifier E2; identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; type T2; @@ fn(... - , T2 E2 ) { ... } @pte_alloc_func_proto_noarg depends on patch exists@ type T1, T2, T3, T4; identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; @@ ( - T3 fn(T1, T2); + T3 fn(T1); | - T3 fn(T1, T2, T4); + T3 fn(T1, T2); ) @pte_alloc_func_proto depends on patch exists@ identifier E1, E2, E4; type T1, T2, T3, T4; identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; @@ ( - T3 fn(T1 E1, T2 E2); + T3 fn(T1 E1); | - T3 fn(T1 E1, T2 E2, T4 E4); + T3 fn(T1 E1, T2 E2); ) @pte_alloc_func_call depends on patch exists@ expression E2; identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; @@ fn(... -, E2 ) @pte_alloc_macro depends on patch exists@ identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$"; identifier a, b, c; expression e; position p; @@ ( - #define fn(a, b, c) e + #define fn(a, b) e | - #define fn(a, b) e + #define fn(a) e ) Link: http://lkml.kernel.org/r/20181108181201.88826-2-joelaf@google.comSigned-off-by: NJoel Fernandes (Google) <joel@joelfernandes.org> Suggested-by: NKirill A. Shutemov <kirill@shutemov.name> Acked-by: NKirill A. Shutemov <kirill@shutemov.name> Cc: Michal Hocko <mhocko@kernel.org> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: William Kucharski <william.kucharski@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Feng Tang 提交于
So that we can also runtime chose to print out the needed system info for panic, other than setting the kernel cmdline. Link: http://lkml.kernel.org/r/1543398842-19295-3-git-send-email-feng.tang@intel.comSigned-off-by: NFeng Tang <feng.tang@intel.com> Suggested-by: NSteven Rostedt <rostedt@goodmis.org> Acked-by: NSteven Rostedt (VMware) <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Tigran Aivazian 提交于
Strengthen validation of BFS superblock against corruption. Make in-core inode bitmap static part of superblock info structure. Print a warning when mounting a BFS filesystem created with "-N 512" option as only 510 files can be created in the root directory. Make the kernel messages more uniform. Update the 'prefix' passed to bfs_dump_imap() to match the current naming of operations. White space and comments cleanup. Link: http://lkml.kernel.org/r/CAK+_RLkFZMduoQF36wZFd3zLi-6ZutWKsydjeHFNdtRvZZEb4w@mail.gmail.comSigned-off-by: NTigran Aivazian <aivazian.tigran@gmail.com> Reported-by: NTetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Oleg Nesterov 提交于
get_arg_page() checks bprm->rlim_stack.rlim_cur and re-calculates the "extra" size for argv/envp pointers every time, this is a bit ugly and even not strictly correct: acct_arg_size() must not account this size. Remove all the rlimit code in get_arg_page(). Instead, add bprm->argmin calculated once at the start of __do_execve_file() and change copy_strings to check bprm->p >= bprm->argmin. The patch adds the new helper, prepare_arg_pages() which initializes bprm->argc/envc and bprm->argmin. [oleg@redhat.com: fix !CONFIG_MMU version of get_arg_page()] Link: http://lkml.kernel.org/r/20181126122307.GA1660@redhat.com [akpm@linux-foundation.org: use max_t] Link: http://lkml.kernel.org/r/20181112160910.GA28440@redhat.comSigned-off-by: NOleg Nesterov <oleg@redhat.com> Acked-by: NKees Cook <keescook@chromium.org> Tested-by: NGuenter Roeck <linux@roeck-us.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Yi Wang 提交于
We get a warning when building kernel with W=1: kernel/fork.c:167:13: warning: no previous prototype for `arch_release_thread_stack' [-Wmissing-prototypes] kernel/fork.c:779:13: warning: no previous prototype for `fork_init' [-Wmissing-prototypes] Add the missing declaration in head file to fix this. Also, remove arch_release_thread_stack() completely because no arch seems to implement it since bb9d8126 (arch: remove tile port). Link: http://lkml.kernel.org/r/1542170087-23645-1-git-send-email-wang.yi59@zte.com.cnSigned-off-by: NYi Wang <wang.yi59@zte.com.cn> Acked-by: NMichal Hocko <mhocko@suse.com> Acked-by: NMike Rapoport <rppt@linux.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Carmeli Tamir 提交于
MAX_FAT is useless in msdos_fs.h, since it uses the MSDOS_SB function that is defined in fat.h. So really, this macro can be only called from code that already includes fat.h. Hence, this patch moves it to fat.h, right after MSDOS_SB is defined. I also changed it to an inline function in order to save the double call to MSDOS_SB. This was suggested by joe@perches.com in the previous version. This patch is required for the next in the series, in which the variant (whether this is FAT12, FAT16 or FAT32) checks are replaced with new macros. Link: http://lkml.kernel.org/r/1544990640-11604-3-git-send-email-carmeli.tamir@gmail.comSigned-off-by: NCarmeli Tamir <carmeli.tamir@gmail.com> Acked-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Carmeli Tamir 提交于
The comment edited in this patch was the only reference to the FAT_FIRST_ENT macro, which is not used anymore. Moreover, the commented line of code does not compile with the current code. Since the FAT_FIRST_ENT macro checks the FAT variant in a way that the patch series changes, I removed it, and instead wrote a clear explanation of what was checked. I verified that the changed comment is correct according to Microsoft FAT spec, search for "BPB_Media" in the following references: 1. Microsoft FAT specification 2005 (http://read.pudn.com/downloads77/ebook/294884/FAT32%20Spec%20%28SDA%20Contribution%29.pdf). Search for 'volume label'. 2. Microsoft Extensible Firmware Initiative, FAT32 File System Specification (https://staff.washington.edu/dittrich/misc/fatgen103.pdf). Search for 'volume label'. Link: http://lkml.kernel.org/r/1544990640-11604-2-git-send-email-carmeli.tamir@gmail.comSigned-off-by: NCarmeli Tamir <carmeli.tamir@gmail.com> Acked-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Carmeli Tamir 提交于
The FAT file system volume label file stored in the root directory should match the volume label field in the FAT boot sector. As consequence, the max length of these fields ought to be the same. This patch replaces the magic '11' usef in the struct fat_boot_sector with MSDOS_NAME, which is used in struct msdos_dir_entry. Please check the following references: 1. Microsoft FAT specification 2005 (http://read.pudn.com/downloads77/ebook/294884/FAT32%20Spec%20%28SDA%20Contribution%29.pdf). Search for 'volume label'. 2. Microsoft Extensible Firmware Initiative, FAT32 File System Specification (https://staff.washington.edu/dittrich/misc/fatgen103.pdf). Search for 'volume label'. 3. User space code that creates FAT filesystem sometimes uses MSDOS_NAME for the label, sometimes not. Search for 'if (memcmp(label, NO_NAME, MSDOS_NAME))'. I consider to make the same patch there as well. https://github.com/dosfstools/dosfstools/blob/master/src/mkfs.fat.c Link: http://lkml.kernel.org/r/1543096879-82837-1-git-send-email-carmeli.tamir@gmail.comSigned-off-by: NCarmeli Tamir <carmeli.tamir@gmail.com> Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de> Acked-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Jens Axboe <axboe@kernel.dk> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Ian Kent 提交于
Commit 092a5345 ("autofs: take more care to not update last_used on path walk") helped to (partially) resolve a problem where automounts were not expiring due to aggressive accesses from user space. This patch was later reverted because, for very large environments, it meant more mount requests from clients and when there are a lot of clients this caused a fairly significant increase in server load. But there is a need for both types of expire check, depending on use case, so add a mount option to allow for strict update of last use of autofs dentrys (which just means not updating the last use on path walk access). Link: http://lkml.kernel.org/r/154296973880.9889.14085372741514507967.stgit@pluto-themaw-netSigned-off-by: NIan Kent <raven@themaw.net> Cc: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Alexey Skidanov 提交于
gen_pool_alloc_algo() uses different allocation functions implementing different allocation algorithms. With gen_pool_first_fit_align() allocation function, the returned address should be aligned on the requested boundary. If chunk start address isn't aligned on the requested boundary, the returned address isn't aligned too. The only way to get properly aligned address is to initialize the pool with chunks aligned on the requested boundary. If want to have an ability to allocate buffers aligned on different boundaries (for example, 4K, 1MB, ...), the chunk start address should be aligned on the max possible alignment. This happens because gen_pool_first_fit_align() looks for properly aligned memory block without taking into account the chunk start address alignment. To fix this, we provide chunk start address to gen_pool_first_fit_align() and change its implementation such that it starts looking for properly aligned block with appropriate offset (exactly as is done in CMA). Link: https://lkml.kernel.org/lkml/a170cf65-6884-3592-1de9-4c235888cc8a@intel.com Link: http://lkml.kernel.org/r/1541690953-4623-1-git-send-email-alexey.skidanov@intel.comSigned-off-by: NAlexey Skidanov <alexey.skidanov@intel.com> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Daniel Mentz <danielmentz@google.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Laura Abbott <labbott@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Matthew Wilcox 提交于
When testing in userspace, UBSAN pointed out that shifting into the sign bit is undefined behaviour. It doesn't really make sense to ask for the highest set bit of a negative value, so just turn the argument type into an unsigned int. Some architectures (eg ppc) already had it declared as an unsigned int, so I don't expect too many problems. Link: http://lkml.kernel.org/r/20181105221117.31828-1-willy@infradead.orgSigned-off-by: NMatthew Wilcox <willy@infradead.org> Acked-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Alexey Dobriyan 提交于
Empty function will be inlined so asmlinkage doesn't do anything. Link: http://lkml.kernel.org/r/20181124093530.GE10969@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com> Reviewed-by: NAndrew Morton <akpm@linux-foundation.org> Acked-by: NJoey Pabalinas <joeypabalinas@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Masahiro Yamada 提交于
The introduction of these dummy BUILD_BUG_ON stubs dates back to commmit 903c0c7c ("sparse: define dummy BUILD_BUG_ON definition for sparse"). At that time, BUILD_BUG_ON() was implemented with the negative array trick *and* the link-time trick, like this: extern int __build_bug_on_failed; #define BUILD_BUG_ON(condition) \ do { \ ((void)sizeof(char[1 - 2*!!(condition)])); \ if (condition) __build_bug_on_failed = 1; \ } while(0) Sparse is more strict about the negative array trick than GCC because Sparse requires the array length to be really constant. Here is the simple test code for the macro above: static const int x = 0; BUILD_BUG_ON(x); GCC is absolutely fine with it (-Wvla was enabled only very recently), but Sparse warns like this: error: bad constant expression error: cannot size expression (If you are using a newer version of Sparse, you will see a different warning message, "warning: Variable length array is used".) Anyway, Sparse was producing many false positives, and noisier than it should be at that time. With the previous commit, the leftover negative array trick is gone. Sparse is fine with the current BUILD_BUG_ON(), which is implemented by using the 'error' attribute. I am keeping the stub for BUILD_BUG_ON_ZERO(). Otherwise, Sparse would complain about the following code, which GCC is fine with: static const int x = 0; int y = BUILD_BUG_ON_ZERO(x); Link: http://lkml.kernel.org/r/1542856462-18836-3-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com> Acked-by: NKees Cook <keescook@chromium.org> Reviewed-by: NLuc Van Oostenryck <luc.vanoostenryck@gmail.com> Reviewed-by: NNick Desaulniers <ndesaulniers@google.com> Tested-by: NNick Desaulniers <ndesaulniers@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Masahiro Yamada 提交于
The kernel can only be compiled with an optimization option (-O2, -Os, or the currently proposed -Og). Hence, __OPTIMIZE__ is always defined in the kernel source. The fallback for the -O0 case is just hypothetical and pointless. Moreover, commit 0bb95f80 ("Makefile: Globally enable VLA warning") enabled -Wvla warning. The use of variable length arrays is banned. Link: http://lkml.kernel.org/r/1542856462-18836-2-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com> Acked-by: NKees Cook <keescook@chromium.org> Reviewed-by: NNick Desaulniers <ndesaulniers@google.com> Tested-by: NNick Desaulniers <ndesaulniers@google.com> Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Linus Torvalds 提交于
Originally, the rule used to be that you'd have to do access_ok() separately, and then user_access_begin() before actually doing the direct (optimized) user access. But experience has shown that people then decide not to do access_ok() at all, and instead rely on it being implied by other operations or similar. Which makes it very hard to verify that the access has actually been range-checked. If you use the unsafe direct user accesses, hardware features (either SMAP - Supervisor Mode Access Protection - on x86, or PAN - Privileged Access Never - on ARM) do force you to use user_access_begin(). But nothing really forces the range check. By putting the range check into user_access_begin(), we actually force people to do the right thing (tm), and the range check vill be visible near the actual accesses. We have way too long a history of people trying to avoid them. Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 04 1月, 2019 5 次提交
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由 Christoph Hellwig 提交于
This avoids link failures in drivers using the DMA API, when they are compiled for user mode Linux with CONFIG_COMPILE_TEST=y. Fixes: 356da6d0 ("dma-mapping: bypass indirect calls for dma-direct") Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
These functions have never been used. Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
dmam_alloc_coherent is just the default no-flags case of dmam_alloc_attrs, so take advantage of this similar to the non-managed version. Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
And also switch the way we implement the unmap side around to stay consistent. This ensures dma-debug works again because it records which function we used for mapping to ensure it is also used for unmapping, and also reduces further code duplication. Last but not least this also officially allows calling dma_sync_single_* for mappings created using dma_map_page, which is perfectly fine given that the sync calls only take a dma_addr_t, but not a virtual address or struct page. Fixes: 7f0fee24 ("dma-mapping: merge dma_unmap_page_attrs and dma_unmap_single_attrs") Signed-off-by: NChristoph Hellwig <hch@lst.de> Tested-by: NLABBE Corentin <clabbe.montjoie@gmail.com>
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由 Linus Torvalds 提交于
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 03 1月, 2019 11 次提交
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由 Daniel Borkmann 提交于
Jann reported that the original commit back in b2157399 ("bpf: prevent out-of-bounds speculation") was not sufficient to stop CPU from speculating out of bounds memory access: While b2157399 only focussed on masking array map access for unprivileged users for tail calls and data access such that the user provided index gets sanitized from BPF program and syscall side, there is still a more generic form affected from BPF programs that applies to most maps that hold user data in relation to dynamic map access when dealing with unknown scalars or "slow" known scalars as access offset, for example: - Load a map value pointer into R6 - Load an index into R7 - Do a slow computation (e.g. with a memory dependency) that loads a limit into R8 (e.g. load the limit from a map for high latency, then mask it to make the verifier happy) - Exit if R7 >= R8 (mispredicted branch) - Load R0 = R6[R7] - Load R0 = R6[R0] For unknown scalars there are two options in the BPF verifier where we could derive knowledge from in order to guarantee safe access to the memory: i) While </>/<=/>= variants won't allow to derive any lower or upper bounds from the unknown scalar where it would be safe to add it to the map value pointer, it is possible through ==/!= test however. ii) another option is to transform the unknown scalar into a known scalar, for example, through ALU ops combination such as R &= <imm> followed by R |= <imm> or any similar combination where the original information from the unknown scalar would be destroyed entirely leaving R with a constant. The initial slow load still precedes the latter ALU ops on that register, so the CPU executes speculatively from that point. Once we have the known scalar, any compare operation would work then. A third option only involving registers with known scalars could be crafted as described in [0] where a CPU port (e.g. Slow Int unit) would be filled with many dependent computations such that the subsequent condition depending on its outcome has to wait for evaluation on its execution port and thereby executing speculatively if the speculated code can be scheduled on a different execution port, or any other form of mistraining as described in [1], for example. Given this is not limited to only unknown scalars, not only map but also stack access is affected since both is accessible for unprivileged users and could potentially be used for out of bounds access under speculation. In order to prevent any of these cases, the verifier is now sanitizing pointer arithmetic on the offset such that any out of bounds speculation would be masked in a way where the pointer arithmetic result in the destination register will stay unchanged, meaning offset masked into zero similar as in array_index_nospec() case. With regards to implementation, there are three options that were considered: i) new insn for sanitation, ii) push/pop insn and sanitation as inlined BPF, iii) reuse of ax register and sanitation as inlined BPF. Option i) has the downside that we end up using from reserved bits in the opcode space, but also that we would require each JIT to emit masking as native arch opcodes meaning mitigation would have slow adoption till everyone implements it eventually which is counter-productive. Option ii) and iii) have both in common that a temporary register is needed in order to implement the sanitation as inlined BPF since we are not allowed to modify the source register. While a push / pop insn in ii) would be useful to have in any case, it requires once again that every JIT needs to implement it first. While possible, amount of changes needed would also be unsuitable for a -stable patch. Therefore, the path which has fewer changes, less BPF instructions for the mitigation and does not require anything to be changed in the JITs is option iii) which this work is pursuing. The ax register is already mapped to a register in all JITs (modulo arm32 where it's mapped to stack as various other BPF registers there) and used in constant blinding for JITs-only so far. It can be reused for verifier rewrites under certain constraints. The interpreter's tmp "register" has therefore been remapped into extending the register set with hidden ax register and reusing that for a number of instructions that needed the prior temporary variable internally (e.g. div, mod). This allows for zero increase in stack space usage in the interpreter, and enables (restricted) generic use in rewrites otherwise as long as such a patchlet does not make use of these instructions. The sanitation mask is dynamic and relative to the offset the map value or stack pointer currently holds. There are various cases that need to be taken under consideration for the masking, e.g. such operation could look as follows: ptr += val or val += ptr or ptr -= val. Thus, the value to be sanitized could reside either in source or in destination register, and the limit is different depending on whether the ALU op is addition or subtraction and depending on the current known and bounded offset. The limit is derived as follows: limit := max_value_size - (smin_value + off). For subtraction: limit := umax_value + off. This holds because we do not allow any pointer arithmetic that would temporarily go out of bounds or would have an unknown value with mixed signed bounds where it is unclear at verification time whether the actual runtime value would be either negative or positive. For example, we have a derived map pointer value with constant offset and bounded one, so limit based on smin_value works because the verifier requires that statically analyzed arithmetic on the pointer must be in bounds, and thus it checks if resulting smin_value + off and umax_value + off is still within map value bounds at time of arithmetic in addition to time of access. Similarly, for the case of stack access we derive the limit as follows: MAX_BPF_STACK + off for subtraction and -off for the case of addition where off := ptr_reg->off + ptr_reg->var_off.value. Subtraction is a special case for the masking which can be in form of ptr += -val, ptr -= -val, or ptr -= val. In the first two cases where we know that the value is negative, we need to temporarily negate the value in order to do the sanitation on a positive value where we later swap the ALU op, and restore original source register if the value was in source. The sanitation of pointer arithmetic alone is still not fully sufficient as is, since a scenario like the following could happen ... PTR += 0x1000 (e.g. K-based imm) PTR -= BIG_NUMBER_WITH_SLOW_COMPARISON PTR += 0x1000 PTR -= BIG_NUMBER_WITH_SLOW_COMPARISON [...] ... which under speculation could end up as ... PTR += 0x1000 PTR -= 0 [ truncated by mitigation ] PTR += 0x1000 PTR -= 0 [ truncated by mitigation ] [...] ... and therefore still access out of bounds. To prevent such case, the verifier is also analyzing safety for potential out of bounds access under speculative execution. Meaning, it is also simulating pointer access under truncation. We therefore "branch off" and push the current verification state after the ALU operation with known 0 to the verification stack for later analysis. Given the current path analysis succeeded it is likely that the one under speculation can be pruned. In any case, it is also subject to existing complexity limits and therefore anything beyond this point will be rejected. In terms of pruning, it needs to be ensured that the verification state from speculative execution simulation must never prune a non-speculative execution path, therefore, we mark verifier state accordingly at the time of push_stack(). If verifier detects out of bounds access under speculative execution from one of the possible paths that includes a truncation, it will reject such program. Given we mask every reg-based pointer arithmetic for unprivileged programs, we've been looking into how it could affect real-world programs in terms of size increase. As the majority of programs are targeted for privileged-only use case, we've unconditionally enabled masking (with its alu restrictions on top of it) for privileged programs for the sake of testing in order to check i) whether they get rejected in its current form, and ii) by how much the number of instructions and size will increase. We've tested this by using Katran, Cilium and test_l4lb from the kernel selftests. For Katran we've evaluated balancer_kern.o, Cilium bpf_lxc.o and an older test object bpf_lxc_opt_-DUNKNOWN.o and l4lb we've used test_l4lb.o as well as test_l4lb_noinline.o. We found that none of the programs got rejected by the verifier with this change, and that impact is rather minimal to none. balancer_kern.o had 13,904 bytes (1,738 insns) xlated and 7,797 bytes JITed before and after the change. Most complex program in bpf_lxc.o had 30,544 bytes (3,817 insns) xlated and 18,538 bytes JITed before and after and none of the other tail call programs in bpf_lxc.o had any changes either. For the older bpf_lxc_opt_-DUNKNOWN.o object we found a small increase from 20,616 bytes (2,576 insns) and 12,536 bytes JITed before to 20,664 bytes (2,582 insns) and 12,558 bytes JITed after the change. Other programs from that object file had similar small increase. Both test_l4lb.o had no change and remained at 6,544 bytes (817 insns) xlated and 3,401 bytes JITed and for test_l4lb_noinline.o constant at 5,080 bytes (634 insns) xlated and 3,313 bytes JITed. This can be explained in that LLVM typically optimizes stack based pointer arithmetic by using K-based operations and that use of dynamic map access is not overly frequent. However, in future we may decide to optimize the algorithm further under known guarantees from branch and value speculation. Latter seems also unclear in terms of prediction heuristics that today's CPUs apply as well as whether there could be collisions in e.g. the predictor's Value History/Pattern Table for triggering out of bounds access, thus masking is performed unconditionally at this point but could be subject to relaxation later on. We were generally also brainstorming various other approaches for mitigation, but the blocker was always lack of available registers at runtime and/or overhead for runtime tracking of limits belonging to a specific pointer. Thus, we found this to be minimally intrusive under given constraints. With that in place, a simple example with sanitized access on unprivileged load at post-verification time looks as follows: # bpftool prog dump xlated id 282 [...] 28: (79) r1 = *(u64 *)(r7 +0) 29: (79) r2 = *(u64 *)(r7 +8) 30: (57) r1 &= 15 31: (79) r3 = *(u64 *)(r0 +4608) 32: (57) r3 &= 1 33: (47) r3 |= 1 34: (2d) if r2 > r3 goto pc+19 35: (b4) (u32) r11 = (u32) 20479 | 36: (1f) r11 -= r2 | Dynamic sanitation for pointer 37: (4f) r11 |= r2 | arithmetic with registers 38: (87) r11 = -r11 | containing bounded or known 39: (c7) r11 s>>= 63 | scalars in order to prevent 40: (5f) r11 &= r2 | out of bounds speculation. 41: (0f) r4 += r11 | 42: (71) r4 = *(u8 *)(r4 +0) 43: (6f) r4 <<= r1 [...] For the case where the scalar sits in the destination register as opposed to the source register, the following code is emitted for the above example: [...] 16: (b4) (u32) r11 = (u32) 20479 17: (1f) r11 -= r2 18: (4f) r11 |= r2 19: (87) r11 = -r11 20: (c7) r11 s>>= 63 21: (5f) r2 &= r11 22: (0f) r2 += r0 23: (61) r0 = *(u32 *)(r2 +0) [...] JIT blinding example with non-conflicting use of r10: [...] d5: je 0x0000000000000106 _ d7: mov 0x0(%rax),%edi | da: mov $0xf153246,%r10d | Index load from map value and e0: xor $0xf153259,%r10 | (const blinded) mask with 0x1f. e7: and %r10,%rdi |_ ea: mov $0x2f,%r10d | f0: sub %rdi,%r10 | Sanitized addition. Both use r10 f3: or %rdi,%r10 | but do not interfere with each f6: neg %r10 | other. (Neither do these instructions f9: sar $0x3f,%r10 | interfere with the use of ax as temp fd: and %r10,%rdi | in interpreter.) 100: add %rax,%rdi |_ 103: mov 0x0(%rdi),%eax [...] Tested that it fixes Jann's reproducer, and also checked that test_verifier and test_progs suite with interpreter, JIT and JIT with hardening enabled on x86-64 and arm64 runs successfully. [0] Speculose: Analyzing the Security Implications of Speculative Execution in CPUs, Giorgi Maisuradze and Christian Rossow, https://arxiv.org/pdf/1801.04084.pdf [1] A Systematic Evaluation of Transient Execution Attacks and Defenses, Claudio Canella, Jo Van Bulck, Michael Schwarz, Moritz Lipp, Benjamin von Berg, Philipp Ortner, Frank Piessens, Dmitry Evtyushkin, Daniel Gruss, https://arxiv.org/pdf/1811.05441.pdf Fixes: b2157399 ("bpf: prevent out-of-bounds speculation") Reported-by: NJann Horn <jannh@google.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Daniel Borkmann 提交于
Right now we are using BPF ax register in JIT for constant blinding as well as in interpreter as temporary variable. Verifier will not be able to use it simply because its use will get overridden from the former in bpf_jit_blind_insn(). However, it can be made to work in that blinding will be skipped if there is prior use in either source or destination register on the instruction. Taking constraints of ax into account, the verifier is then open to use it in rewrites under some constraints. Note, ax register already has mappings in every eBPF JIT. Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Daniel Borkmann 提交于
This change moves the on-stack 64 bit tmp variable in ___bpf_prog_run() into the hidden ax register. The latter is currently only used in JITs for constant blinding as a temporary scratch register, meaning the BPF interpreter will never see the use of ax. Therefore it is safe to use it for the cases where tmp has been used earlier. This is needed to later on allow restricted hidden use of ax in both interpreter and JITs. Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Daniel Borkmann 提交于
Move prev_insn_idx and insn_idx from the do_check() function into the verifier environment, so they can be read inside the various helper functions for handling the instructions. It's easier to put this into the environment rather than changing all call-sites only to pass it along. insn_idx is useful in particular since this later on allows to hold state in env->insn_aux_data[env->insn_idx]. Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Santosh kumar pradhan 提交于
Multipathing: In case of NFSv3, rpc_clnt_test_and_add_xprt() adds the xprt to xprt switch (i.e. xps) if rpc_call_null_helper() returns success. But in case of NFSv4.1, it needs to do EXCHANGEID to verify the path along with check for session trunking. Add the xprt in nfs4_test_session_trunk() only when nfs4_detect_session_trunking() returns success. Also release refcount hold by rpc_clnt_setup_test_and_add_xprt(). Signed-off-by: NSantosh kumar pradhan <santoshkumar.pradhan@wdc.com> Tested-by: NSuresh Jayaraman <suresh.jayaraman@wdc.com> Reported-by: NAditya Agnihotri <aditya.agnihotri@wdc.com> Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
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由 Chuck Lever 提交于
If a reply has been processed but the RPC is later retransmitted anyway, the req->rl_reply field still contains the only pointer to the old rpcrdma rep. When the next reply comes in, the reply handler will stomp on the rl_reply field, leaking the old rep. A trace event is added to capture such leaks. This problem seems to be worsened by the restructuring of the RPC Call path in v4.20. Fully addressing this issue will require at least a re-architecture of the disconnect logic, which is not appropriate during -rc. Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
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由 Chuck Lever 提交于
Clean up, no functional change is expected. Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
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由 Chuck Lever 提交于
These are rare, but can be helpful at tracking down DMAR and other problems. Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
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由 Chuck Lever 提交于
Name them "trace_xprtrdma_op_*" so they can be easily enabled as a group. No trace point is added where the generic layer already has observability. Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
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由 Chuck Lever 提交于
The chunk-related trace points capture nearly the same information as the MR-related trace points. Also, rename them so globbing can be used to enable or disable these trace points more easily. Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
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由 Chuck Lever 提交于
Clean up: Divide the work cleanly: - rpcrdma_wc_receive is responsible only for RDMA Receives - rpcrdma_reply_handler is responsible only for RPC Replies - the posted send and receive counts both belong in rpcrdma_ep Signed-off-by: NChuck Lever <chuck.lever@oracle.com> Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
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- 02 1月, 2019 1 次提交
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由 Thierry Reding 提交于
The thermal controller implementation on Tegra194 is very similar to the implementation on Tegra186. Add a compatible string for the new generation. Signed-off-by: NThierry Reding <treding@nvidia.com> Signed-off-by: NEduardo Valentin <edubezval@gmail.com>
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