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2016-04-20kbuild: delete unnecessary "@:"Masahiro Yamada
Since commit 2aedcd098a94 ('kbuild: suppress annoying "... is up to date." message'), $(call if_changed,...) is evaluated to "@:" when there is nothing to do. We no longer need to add "@:" after $(call if_changed,...) to suppress "... is up to date." message. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-04-19x86/KASLR: Rename "random" to "random_addr"Kees Cook
The variable "random" is also the name of a libc function. It's better coding style to avoid overloading such things, so rename it to the more accurate "random_addr". Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1460997735-24785-7-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-19x86/KASLR: Clarify purpose of kaslr.cKees Cook
The name "choose_kernel_location" isn't specific enough, and doesn't describe the primary thing it does: choosing a random location. This patch renames it to "choose_random_location", and clarifies the what routines are contained in the kaslr.c source file. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1460997735-24785-6-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-19x86/boot: Clarify purpose of functions in misc.cKees Cook
The function "decompress_kernel" now performs many more duties, so this patch renames it to "extract_kernel" and updates callers and comments. Additionally the file header comment for misc.c is improved to actually describe what is contained. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1460997735-24785-5-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-19x86/boot: Rename "real_mode" to "boot_params"Kees Cook
The non-compressed boot code uses the (much more obvious) name "boot_params" for the global pointer to the x86 boot parameters. The compressed kernel loader code, though, was using the legacy name "real_mode". There is no need to have a different name, and changing it improves readability. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1460997735-24785-4-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-19x86/KASLR: Remove unneeded boot_params argumentYinghai Lu
Since the boot_params can be found using the real_mode global variable, there is no need to pass around a pointer to it. This slightly simplifies the choose_kernel_location function and its callers. [kees: rewrote changelog, tracked file rename] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1460997735-24785-3-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-19x86/KASLR: Rename aslr.c to kaslr.cKees Cook
In order to avoid confusion over what this file provides, rename it to kaslr.c since it is used exclusively for the kernel ASLR, not userspace ASLR. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1460997735-24785-2-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-29x86/build: Build compressed x86 kernels as PIEH.J. Lu
The 32-bit x86 assembler in binutils 2.26 will generate R_386_GOT32X relocation to get the symbol address in PIC. When the compressed x86 kernel isn't built as PIC, the linker optimizes R_386_GOT32X relocations to their fixed symbol addresses. However, when the compressed x86 kernel is loaded at a different address, it leads to the following load failure: Failed to allocate space for phdrs during the decompression stage. If the compressed x86 kernel is relocatable at run-time, it should be compiled with -fPIE, instead of -fPIC, if possible and should be built as Position Independent Executable (PIE) so that linker won't optimize R_386_GOT32X relocation to its fixed symbol address. Older linkers generate R_386_32 relocations against locally defined symbols, _bss, _ebss, _got and _egot, in PIE. It isn't wrong, just less optimal than R_386_RELATIVE. But the x86 kernel fails to properly handle R_386_32 relocations when relocating the kernel. To generate R_386_RELATIVE relocations, we mark _bss, _ebss, _got and _egot as hidden in both 32-bit and 64-bit x86 kernels. To build a 64-bit compressed x86 kernel as PIE, we need to disable the relocation overflow check to avoid relocation overflow errors. We do this with a new linker command-line option, -z noreloc-overflow, which got added recently: commit 4c10bbaa0912742322f10d9d5bb630ba4e15dfa7 Author: H.J. Lu <hjl.tools@gmail.com> Date: Tue Mar 15 11:07:06 2016 -0700 Add -z noreloc-overflow option to x86-64 ld Add -z noreloc-overflow command-line option to the x86-64 ELF linker to disable relocation overflow check. This can be used to avoid relocation overflow check if there will be no dynamic relocation overflow at run-time. The 64-bit compressed x86 kernel is built as PIE only if the linker supports -z noreloc-overflow. So far 64-bit relocatable compressed x86 kernel boots fine even when it is built as a normal executable. Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org [ Edited the changelog and comments. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-22kernel: add kcov code coverageDmitry Vyukov
kcov provides code coverage collection for coverage-guided fuzzing (randomized testing). Coverage-guided fuzzing is a testing technique that uses coverage feedback to determine new interesting inputs to a system. A notable user-space example is AFL (http://lcamtuf.coredump.cx/afl/). However, this technique is not widely used for kernel testing due to missing compiler and kernel support. kcov does not aim to collect as much coverage as possible. It aims to collect more or less stable coverage that is function of syscall inputs. To achieve this goal it does not collect coverage in soft/hard interrupts and instrumentation of some inherently non-deterministic or non-interesting parts of kernel is disbled (e.g. scheduler, locking). Currently there is a single coverage collection mode (tracing), but the API anticipates additional collection modes. Initially I also implemented a second mode which exposes coverage in a fixed-size hash table of counters (what Quentin used in his original patch). I've dropped the second mode for simplicity. This patch adds the necessary support on kernel side. The complimentary compiler support was added in gcc revision 231296. We've used this support to build syzkaller system call fuzzer, which has found 90 kernel bugs in just 2 months: https://github.com/google/syzkaller/wiki/Found-Bugs We've also found 30+ bugs in our internal systems with syzkaller. Another (yet unexplored) direction where kcov coverage would greatly help is more traditional "blob mutation". For example, mounting a random blob as a filesystem, or receiving a random blob over wire. Why not gcov. Typical fuzzing loop looks as follows: (1) reset coverage, (2) execute a bit of code, (3) collect coverage, repeat. A typical coverage can be just a dozen of basic blocks (e.g. an invalid input). In such context gcov becomes prohibitively expensive as reset/collect coverage steps depend on total number of basic blocks/edges in program (in case of kernel it is about 2M). Cost of kcov depends only on number of executed basic blocks/edges. On top of that, kernel requires per-thread coverage because there are always background threads and unrelated processes that also produce coverage. With inlined gcov instrumentation per-thread coverage is not possible. kcov exposes kernel PCs and control flow to user-space which is insecure. But debugfs should not be mapped as user accessible. Based on a patch by Quentin Casasnovas. [akpm@linux-foundation.org: make task_struct.kcov_mode have type `enum kcov_mode'] [akpm@linux-foundation.org: unbreak allmodconfig] [akpm@linux-foundation.org: follow x86 Makefile layout standards] Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: syzkaller <syzkaller@googlegroups.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Tavis Ormandy <taviso@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Kees Cook <keescook@google.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: David Drysdale <drysdale@google.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-20Merge branch 'core-objtool-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull 'objtool' stack frame validation from Ingo Molnar: "This tree adds a new kernel build-time object file validation feature (ONFIG_STACK_VALIDATION=y): kernel stack frame correctness validation. It was written by and is maintained by Josh Poimboeuf. The motivation: there's a category of hard to find kernel bugs, most of them in assembly code (but also occasionally in C code), that degrades the quality of kernel stack dumps/backtraces. These bugs are hard to detect at the source code level. Such bugs result in incorrect/incomplete backtraces most of time - but can also in some rare cases result in crashes or other undefined behavior. The build time correctness checking is done via the new 'objtool' user-space utility that was written for this purpose and which is hosted in the kernel repository in tools/objtool/. The tool's (very simple) UI and source code design is shaped after Git and perf and shares quite a bit of infrastructure with tools/perf (which tooling infrastructure sharing effort got merged via perf and is already upstream). Objtool follows the well-known kernel coding style. Objtool does not try to check .c or .S files, it instead analyzes the resulting .o generated machine code from first principles: it decodes the instruction stream and interprets it. (Right now objtool supports the x86-64 architecture.) From tools/objtool/Documentation/stack-validation.txt: "The kernel CONFIG_STACK_VALIDATION option enables a host tool named objtool which runs at compile time. It has a "check" subcommand which analyzes every .o file and ensures the validity of its stack metadata. It enforces a set of rules on asm code and C inline assembly code so that stack traces can be reliable. Currently it only checks frame pointer usage, but there are plans to add CFI validation for C files and CFI generation for asm files. For each function, it recursively follows all possible code paths and validates the correct frame pointer state at each instruction. It also follows code paths involving special sections, like .altinstructions, __jump_table, and __ex_table, which can add alternative execution paths to a given instruction (or set of instructions). Similarly, it knows how to follow switch statements, for which gcc sometimes uses jump tables." When this new kernel option is enabled (it's disabled by default), the tool, if it finds any suspicious assembly code pattern, outputs warnings in compiler warning format: warning: objtool: rtlwifi_rate_mapping()+0x2e7: frame pointer state mismatch warning: objtool: cik_tiling_mode_table_init()+0x6ce: call without frame pointer save/setup warning: objtool:__schedule()+0x3c0: duplicate frame pointer save warning: objtool:__schedule()+0x3fd: sibling call from callable instruction with changed frame pointer ... so that scripts that pick up compiler warnings will notice them. All known warnings triggered by the tool are fixed by the tree, most of the commits in fact prepare the kernel to be warning-free. Most of them are bugfixes or cleanups that stand on their own, but there are also some annotations of 'special' stack frames for justified cases such entries to JIT-ed code (BPF) or really special boot time code. There are two other long-term motivations behind this tool as well: - To improve the quality and reliability of kernel stack frames, so that they can be used for optimized live patching. - To create independent infrastructure to check the correctness of CFI stack frames at build time. CFI debuginfo is notoriously unreliable and we cannot use it in the kernel as-is without extra checking done both on the kernel side and on the build side. The quality of kernel stack frames matters to debuggability as well, so IMO we can merge this without having to consider the live patching or CFI debuginfo angle" * 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) objtool: Only print one warning per function objtool: Add several performance improvements tools: Copy hashtable.h into tools directory objtool: Fix false positive warnings for functions with multiple switch statements objtool: Rename some variables and functions objtool: Remove superflous INIT_LIST_HEAD objtool: Add helper macros for traversing instructions objtool: Fix false positive warnings related to sibling calls objtool: Compile with debugging symbols objtool: Detect infinite recursion objtool: Prevent infinite recursion in noreturn detection objtool: Detect and warn if libelf is missing and don't break the build tools: Support relative directory path for 'O=' objtool: Support CROSS_COMPILE x86/asm/decoder: Use explicitly signed chars objtool: Enable stack metadata validation on 64-bit x86 objtool: Add CONFIG_STACK_VALIDATION option objtool: Add tool to perform compile-time stack metadata validation x86/kprobes: Mark kretprobe_trampoline() stack frame as non-standard sched: Always inline context_switch() ...
2016-03-15Merge branch 'x86-boot-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Ingo Molnar: "Early command line options parsing enhancements from Dave Hansen, plus minor cleanups and enhancements" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Remove unused 'is_big_kernel' variable x86/boot: Use proper array element type in memset() size calculation x86/boot: Pass in size to early cmdline parsing x86/boot: Simplify early command line parsing x86/boot: Fix early command-line parsing when partial word matches x86/boot: Fix early command-line parsing when matching at end x86/boot: Simplify kernel load address alignment check x86/boot: Micro-optimize reset_early_page_tables()
2016-02-29objtool: Mark non-standard object files and directoriesJosh Poimboeuf
Code which runs outside the kernel's normal mode of operation often does unusual things which can cause a static analysis tool like objtool to emit false positive warnings: - boot image - vdso image - relocation - realmode - efi - head - purgatory - modpost Set OBJECT_FILES_NON_STANDARD for their related files and directories, which will tell objtool to skip checking them. It's ok to skip them because they don't affect runtime stack traces. Also skip the following code which does the right thing with respect to frame pointers, but is too "special" to be validated by a tool: - entry - mcount Also skip the test_nx module because it modifies its exception handling table at runtime, which objtool can't understand. Fortunately it's just a test module so it doesn't matter much. Currently objtool is the only user of OBJECT_FILES_NON_STANDARD, but it might eventually be useful for other tools. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/366c080e3844e8a5b6a0327dc7e8c2b90ca3baeb.1456719558.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-16x86/boot: Remove unused 'is_big_kernel' variableNicolas Iooss
Variable is_big_kernel is defined in arch/x86/boot/tools/build.c but never used anywhere. Boris noted that its usage went away 7 years ago, as of: 5e47c478b0b6 ("x86: remove zImage support") Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1455453358-4088-1-git-send-email-nicolas.iooss_linux@m4x.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-30x86/cpufeature: Carve out X86_FEATURE_*Borislav Petkov
Move them to a separate header and have the following dependency: x86/cpufeatures.h <- x86/processor.h <- x86/cpufeature.h This makes it easier to use the header in asm code and not include the whole cpufeature.h and add guards for asm. Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1453842730-28463-5-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-20UBSAN: run-time undefined behavior sanity checkerAndrey Ryabinin
UBSAN uses compile-time instrumentation to catch undefined behavior (UB). Compiler inserts code that perform certain kinds of checks before operations that could cause UB. If check fails (i.e. UB detected) __ubsan_handle_* function called to print error message. So the most of the work is done by compiler. This patch just implements ubsan handlers printing errors. GCC has this capability since 4.9.x [1] (see -fsanitize=undefined option and its suboptions). However GCC 5.x has more checkers implemented [2]. Article [3] has a bit more details about UBSAN in the GCC. [1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html [2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html [3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/ Issues which UBSAN has found thus far are: Found bugs: * out-of-bounds access - 97840cb67ff5 ("netfilter: nfnetlink: fix insufficient validation in nfnetlink_bind") undefined shifts: * d48458d4a768 ("jbd2: use a better hash function for the revoke table") * 10632008b9e1 ("clockevents: Prevent shift out of bounds") * 'x << -1' shift in ext4 - http://lkml.kernel.org/r/<5444EF21.8020501@samsung.com> * undefined rol32(0) - http://lkml.kernel.org/r/<1449198241-20654-1-git-send-email-sasha.levin@oracle.com> * undefined dirty_ratelimit calculation - http://lkml.kernel.org/r/<566594E2.3050306@odin.com> * undefined roundown_pow_of_two(0) - http://lkml.kernel.org/r/<1449156616-11474-1-git-send-email-sasha.levin@oracle.com> * [WONTFIX] undefined shift in __bpf_prog_run - http://lkml.kernel.org/r/<CACT4Y+ZxoR3UjLgcNdUm4fECLMx2VdtfrENMtRRCdgHB2n0bJA@mail.gmail.com> WONTFIX here because it should be fixed in bpf program, not in kernel. signed overflows: * 32a8df4e0b33f ("sched: Fix odd values in effective_load() calculations") * mul overflow in ntp - http://lkml.kernel.org/r/<1449175608-1146-1-git-send-email-sasha.levin@oracle.com> * incorrect conversion into rtc_time in rtc_time64_to_tm() - http://lkml.kernel.org/r/<1449187944-11730-1-git-send-email-sasha.levin@oracle.com> * unvalidated timespec in io_getevents() - http://lkml.kernel.org/r/<CACT4Y+bBxVYLQ6LtOKrKtnLthqLHcw-BMp3aqP3mjdAvr9FULQ@mail.gmail.com> * [NOTABUG] signed overflow in ktime_add_safe() - http://lkml.kernel.org/r/<CACT4Y+aJ4muRnWxsUe1CMnA6P8nooO33kwG-c8YZg=0Xc8rJqw@mail.gmail.com> [akpm@linux-foundation.org: fix unused local warning] [akpm@linux-foundation.org: fix __int128 build woes] Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Marek <mmarek@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Yury Gribov <y.gribov@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-04x86/mm: Fix regression with huge pages on PAEKirill A. Shutemov
Recent PAT patchset has caused issue on 32-bit PAE machines: page:eea45000 count:0 mapcount:-128 mapping: (null) index:0x0 flags: 0x40000000() page dumped because: VM_BUG_ON_PAGE(page_mapcount(page) < 0) ------------[ cut here ]------------ kernel BUG at /home/build/linux-boris/mm/huge_memory.c:1485! invalid opcode: 0000 [#1] SMP [...] Call Trace: unmap_single_vma ? __wake_up unmap_vmas unmap_region do_munmap vm_munmap SyS_munmap do_fast_syscall_32 ? __do_page_fault sysenter_past_esp Code: ... EIP: [<c11bde80>] zap_huge_pmd+0x240/0x260 SS:ESP 0068:f6459d98 The problem is in pmd_pfn_mask() and pmd_flags_mask(). These helpers use PMD_PAGE_MASK to calculate resulting mask. PMD_PAGE_MASK is 'unsigned long', not 'unsigned long long' as phys_addr_t is on 32-bit PAE (ARCH_PHYS_ADDR_T_64BIT). As a result, the upper bits of resulting mask get truncated. pud_pfn_mask() and pud_flags_mask() aren't problematic since we don't have PUD page table level on 32-bit systems, but it's reasonable to keep them consistent with PMD counterpart. Introduce PHYSICAL_PMD_PAGE_MASK and PHYSICAL_PUD_PAGE_MASK in addition to existing PHYSICAL_PAGE_MASK and reworks helpers to use them. Reported-and-Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> [ Fix -Woverflow warnings from the realmode code. ] Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Toshi Kani <toshi.kani@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jürgen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: elliott@hpe.com Cc: konrad.wilk@oracle.com Cc: linux-mm <linux-mm@kvack.org> Fixes: f70abb0fc3da ("x86/asm: Fix pud/pmd interfaces to handle large PAT bit") Link: http://lkml.kernel.org/r/1448878233-11390-2-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-05kasan: move KASAN_SANITIZE in arch/x86/boot/MakefileAndrey Konovalov
Move KASAN_SANITIZE in arch/x86/boot/Makefile above the comment related to SVGA_MODE, since the comment refers to 'the next line'. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Konstantin Serebryany <kcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-14Merge tag 'efi-next' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into core/efi Pull v4.4 EFI updates from Matt Fleming: - Make the EFI System Resource Table (ESRT) driver explicitly non-modular by ripping out the module_* code since Kconfig doesn't allow it to be built as a module anyway. (Paul Gortmaker) - Make the x86 efi=debug kernel parameter, which enables EFI debug code and output, generic and usable by arm64. (Leif Lindholm) - Add support to the x86 EFI boot stub for 64-bit Graphics Output Protocol frame buffer addresses. (Matt Fleming) - Detect when the UEFI v2.5 EFI_PROPERTIES_TABLE feature is enabled in the firmware and set an efi.flags bit so the kernel knows when it can apply more strict runtime mapping attributes - Ard Biesheuvel - Auto-load the efi-pstore module on EFI systems, just like we currently do for the efivars module. (Ben Hutchings) - Add "efi_fake_mem" kernel parameter which allows the system's EFI memory map to be updated with additional attributes for specific memory ranges. This is useful for testing the kernel code that handles the EFI_MEMORY_MORE_RELIABLE memmap bit even if your firmware doesn't include support. (Taku Izumi) Note: there is a semantic conflict between the following two commits: 8a53554e12e9 ("x86/efi: Fix multiple GOP device support") ae2ee627dc87 ("efifb: Add support for 64-bit frame buffer addresses") I fixed up the interaction in the merge commit, changing the type of current_fb_base from u32 to u64. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-14Merge branch 'x86/urgent' into core/efi, to pick up a pending EFI fixIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-14x86/efi: Fix multiple GOP device supportKővágó, Zoltán
When multiple GOP devices exists, but none of them implements ConOut, the code should just choose the first GOP (according to the comments). But currently 'fb_base' will refer to the last GOP, while other parameters to the first GOP, which will likely result in a garbled display. I can reliably reproduce this bug using my ASRock Z87M Extreme4 motherboard with CSM and integrated GPU disabled, and two PCIe video cards (NVidia GT640 and GTX980), booting from efi-stub (booting from grub works fine). On the primary display the ASRock logo remains and on the secondary screen it is garbled up completely. Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Cc: <stable@vger.kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1444659236-24837-2-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-12efifb: Add support for 64-bit frame buffer addressesMatt Fleming
The EFI Graphics Output Protocol uses 64-bit frame buffer addresses but these get truncated to 32-bit by the EFI boot stub when storing the address in the 'lfb_base' field of 'struct screen_info'. Add a 'ext_lfb_base' field for the upper 32-bits of the frame buffer address and set VIDEO_TYPE_CAPABILITY_64BIT_BASE when the field is useable. It turns out that the reason no one has required this support so far is that there's actually code in tianocore to "downgrade" PCI resources that have option ROMs and 64-bit BARS from 64-bit to 32-bit to cope with legacy option ROMs that can't handle 64-bit addresses. The upshot is that basically all GOP devices in the wild use a 32-bit frame buffer address. Still, it is possible to build firmware that uses a full 64-bit GOP frame buffer address. Chad did, which led to him reporting this issue. Add support in anticipation of GOP devices using 64-bit addresses more widely, and so that efifb works out of the box when that happens. Reported-by: Chad Page <chad.page@znyx.com> Cc: Pete Hawkins <pete.hawkins@znyx.com> Acked-by: Peter Jones <pjones@redhat.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-09-10lib/decompressors: use real out buf size for gunzip with kernelYinghai Lu
When loading x86 64bit kernel above 4GiB with patched grub2, got kernel gunzip error. | early console in decompress_kernel | decompress_kernel: | input: [0x807f2143b4-0x807ff61aee] | output: [0x807cc00000-0x807f3ea29b] 0x027ea29c: output_len | boot via startup_64 | KASLR using RDTSC... | new output: [0x46fe000000-0x470138cfff] 0x0338d000: output_run_size | decompress: [0x46fe000000-0x47007ea29b] <=== [0x807f2143b4-0x807ff61aee] | | Decompressing Linux... gz... | | uncompression error | | -- System halted the new buffer is at 0x46fe000000ULL, decompressor_gzip is using 0xffffffb901ffffff as out_len. gunzip in lib/zlib_inflate/inflate.c cap that len to 0x01ffffff and decompress fails later. We could hit this problem with crashkernel booting that uses kexec loading kernel above 4GiB. We have decompress_* support: 1. inbuf[]/outbuf[] for kernel preboot. 2. inbuf[]/flush() for initramfs 3. fill()/flush() for initrd. This bug only affect kernel preboot path that use outbuf[]. Add __decompress and take real out_buf_len for gunzip instead of guessing wrong buf size. Fixes: 1431574a1c4 (lib/decompressors: fix "no limit" output buffer length) Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Alexandre Courbot <acourbot@nvidia.com> Cc: Jon Medhurst <tixy@linaro.org> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10kexec: split kexec_load syscall from kexec core codeDave Young
There are two kexec load syscalls, kexec_load another and kexec_file_load. kexec_file_load has been splited as kernel/kexec_file.c. In this patch I split kexec_load syscall code to kernel/kexec.c. And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and use kexec_file_load only, or vice verse. The original requirement is from Ted Ts'o, he want kexec kernel signature being checked with CONFIG_KEXEC_VERIFY_SIG enabled. But kexec-tools use kexec_load syscall can bypass the checking. Vivek Goyal proposed to create a common kconfig option so user can compile in only one syscall for loading kexec kernel. KEXEC/KEXEC_FILE selects KEXEC_CORE so that old config files still work. Because there's general code need CONFIG_KEXEC_CORE, so I updated all the architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects KEXEC_CORE in arch Kconfig. Also updated general kernel code with to kexec_load syscall. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Dave Young <dyoung@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Petr Tesarik <ptesarik@suse.cz> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Josh Boyer <jwboyer@fedoraproject.org> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-01Merge branch 'x86-boot-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Ingo Molnar: "The main x86 bootup related changes in this cycle were: - more boot time optimizations. (Len Brown) - implement hex output to allow the debugging of early bootup parameters. (Kees Cook) - remove obsolete MCA leftovers. (Paolo Pisati)" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/smpboot: Remove APIC.wait_for_init_deassert and atomic init_deasserted x86/smpboot: Remove SIPI delays from cpu_up() x86/smpboot: Remove udelay(100) when polling cpu_callin_map x86/smpboot: Remove udelay(100) when polling cpu_initialized_map x86/boot: Obsolete the MCA sys_desc_table x86/boot: Add hex output for debugging
2015-08-17Merge tag 'v4.2-rc7' into x86/boot, to refresh the branch before merging new ↵Ingo Molnar
changes Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-08Revert "x86/efi: Request desired alignment via the PE/COFF headers"Matt Fleming
This reverts commit: aeffc4928ea2 ("x86/efi: Request desired alignment via the PE/COFF headers") Linn reports that Signtool complains that kernels built with CONFIG_EFI_STUB=y are violating the PE/COFF specification because the 'SizeOfImage' field is not a multiple of 'SectionAlignment'. This violation was introduced as an optimisation to skip having the kernel relocate itself during boot and instead have the firmware place it at a correctly aligned address. No one else has complained and I'm not aware of any firmware implementations that refuse to boot with commit aeffc4928ea2, but it's a real bug, so revert the offending commit. Reported-by: Linn Crosetto <linn@hp.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Brown <mbrown@fensystems.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1438936621-5215-3-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-31Merge branch 'x86/urgent' into x86/asm, before applying dependent patchesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-30x86/efi: Use all 64 bit of efi_memmap in setup_e820()Dmitry Skorodumov
The efi_info structure stores low 32 bits of memory map in efi_memmap and high 32 bits in efi_memmap_hi. While constructing pointer in the setup_e820(), need to take into account all 64 bit of the pointer. It is because on 64bit machine the function efi_get_memory_map() may return full 64bit pointer and before the patch that pointer was truncated. The issue is triggered on Parallles virtual machine and fixed with this patch. Signed-off-by: Dmitry Skorodumov <sdmitry@parallels.com> Cc: Denis V. Lunev <den@openvz.org> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-07-21x86/boot: Obsolete the MCA sys_desc_tablePaolo Pisati
The kernel does not support the MCA bus anymroe, so mark sys_desc_table as obsolete: remove any reference from the code together with the remaining of MCA logic. bloat-o-meter output: add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-55 (-55) function old new delta i386_start_kernel 128 119 -9 setup_arch 1421 1375 -46 Signed-off-by: Paolo Pisati <p.pisati@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1437409430-8491-1-git-send-email-p.pisati@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-07x86/boot: Add hex output for debuggingKees Cook
This is useful for reporting various addresses or other values while debugging early boot, for example, the recent kernel image size vs kernel run size. For example, when CONFIG_X86_VERBOSE_BOOTUP is set, this is now visible at boot time: early console in setup code early console in decompress_kernel input_data: 0x0000000001e1526e input_len: 0x0000000000732236 output: 0x0000000001000000 output_len: 0x0000000001535640 run_size: 0x00000000021fb000 KASLR using RDTSC... Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@suse.de> Cc: Jan Beulich <JBeulich@suse.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Joe Perches <joe@perches.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Junjie Mao <eternal.n08@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20150706230620.GA17501@www.outflux.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06x86/asm/tsc: Rename native_read_tsc() to rdtsc()Andy Lutomirski
Now that there is no paravirt TSC, the "native" is inappropriate. The function does RDTSC, so give it the obvious name: rdtsc(). Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/fd43e16281991f096c1e4d21574d9e1402c62d39.1434501121.git.luto@kernel.org [ Ported it to v4.2-rc1. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06x86/asm/tsc: Replace rdtscll() with native_read_tsc()Andy Lutomirski
Now that the ->read_tsc() paravirt hook is gone, rdtscll() is just a wrapper around native_read_tsc(). Unwrap it. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/d2449ae62c1b1fb90195bcfb19ef4a35883a04dc.1434501121.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-29Merge tag 'libnvdimm-for-4.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm Pull libnvdimm subsystem from Dan Williams: "The libnvdimm sub-system introduces, in addition to the libnvdimm-core, 4 drivers / enabling modules: NFIT: Instantiates an "nvdimm bus" with the core and registers memory devices (NVDIMMs) enumerated by the ACPI 6.0 NFIT (NVDIMM Firmware Interface table). After registering NVDIMMs the NFIT driver then registers "region" devices. A libnvdimm-region defines an access mode and the boundaries of persistent memory media. A region may span multiple NVDIMMs that are interleaved by the hardware memory controller. In turn, a libnvdimm-region can be carved into a "namespace" device and bound to the PMEM or BLK driver which will attach a Linux block device (disk) interface to the memory. PMEM: Initially merged in v4.1 this driver for contiguous spans of persistent memory address ranges is re-worked to drive PMEM-namespaces emitted by the libnvdimm-core. In this update the PMEM driver, on x86, gains the ability to assert that writes to persistent memory have been flushed all the way through the caches and buffers in the platform to persistent media. See memcpy_to_pmem() and wmb_pmem(). BLK: This new driver enables access to persistent memory media through "Block Data Windows" as defined by the NFIT. The primary difference of this driver to PMEM is that only a small window of persistent memory is mapped into system address space at any given point in time. Per-NVDIMM windows are reprogrammed at run time, per-I/O, to access different portions of the media. BLK-mode, by definition, does not support DAX. BTT: This is a library, optionally consumed by either PMEM or BLK, that converts a byte-accessible namespace into a disk with atomic sector update semantics (prevents sector tearing on crash or power loss). The sinister aspect of sector tearing is that most applications do not know they have a atomic sector dependency. At least today's disk's rarely ever tear sectors and if they do one almost certainly gets a CRC error on access. NVDIMMs will always tear and always silently. Until an application is audited to be robust in the presence of sector-tearing the usage of BTT is recommended. Thanks to: Ross Zwisler, Jeff Moyer, Vishal Verma, Christoph Hellwig, Ingo Molnar, Neil Brown, Boaz Harrosh, Robert Elliott, Matthew Wilcox, Andy Rudoff, Linda Knippers, Toshi Kani, Nicholas Moulin, Rafael Wysocki, and Bob Moore" * tag 'libnvdimm-for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm: (33 commits) arch, x86: pmem api for ensuring durability of persistent memory updates libnvdimm: Add sysfs numa_node to NVDIMM devices libnvdimm: Set numa_node to NVDIMM devices acpi: Add acpi_map_pxm_to_online_node() libnvdimm, nfit: handle unarmed dimms, mark namespaces read-only pmem: flag pmem block devices as non-rotational libnvdimm: enable iostat pmem: make_request cleanups libnvdimm, pmem: fix up max_hw_sectors libnvdimm, blk: add support for blk integrity libnvdimm, btt: add support for blk integrity fs/block_dev.c: skip rw_page if bdev has integrity libnvdimm: Non-Volatile Devices tools/testing/nvdimm: libnvdimm unit test infrastructure libnvdimm, nfit, nd_blk: driver for BLK-mode access persistent memory nd_btt: atomic sector updates libnvdimm: infrastructure for btt devices libnvdimm: write blk label set libnvdimm: write pmem label set libnvdimm: blk labels and namespace instantiation ...
2015-05-29x86/boot: Add CONFIG_PARAVIRT_SPINLOCKS quirk to arch/x86/boot/compressed/misc.hIngo Molnar
Linus reported the following new warning on x86 allmodconfig with GCC 5.1: > ./arch/x86/include/asm/spinlock.h: In function ‘arch_spin_lock’: > ./arch/x86/include/asm/spinlock.h:119:3: warning: implicit declaration > of function ‘__ticket_lock_spinning’ [-Wimplicit-function-declaration] > __ticket_lock_spinning(lock, inc.tail); > ^ This warning triggers because of these hacks in misc.h: /* * we have to be careful, because no indirections are allowed here, and * paravirt_ops is a kind of one. As it will only run in baremetal anyway, * we just keep it from happening */ #undef CONFIG_PARAVIRT #undef CONFIG_KASAN But these hacks were not updated when CONFIG_PARAVIRT_SPINLOCKS was added, and eventually (with the introduction of queued paravirt spinlocks in recent kernels) this created an invalid Kconfig combination and broke the build. So add a CONFIG_PARAVIRT_SPINLOCKS #undef line as well. Also remove the _ASM_X86_DESC_H quirk: that undocumented quirk was originally added ages ago, in: 099e1377269a ("x86: use ELF format in compressed images.") and I went back to that kernel (and fixed up the main Makefile which didn't build anymore) and checked what failure it avoided: it avoided an include file dependencies related build failure related to our old x86-platforms code. That old code is long gone, the header dependencies got cleaned up, and the build does not fail anymore with the totality of asm/desc.h included - so remove the quirk. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27e820, efi: add ACPI 6.0 persistent memory typesDan Williams
ACPI 6.0 formalizes e820-type-7 and efi-type-14 as persistent memory. Mark it "reserved" and allow it to be claimed by a persistent memory device driver. This definition is in addition to the Linux kernel's existing type-12 definition that was recently added in support of shipping platforms with NVDIMM support that predate ACPI 6.0 (which now classifies type-12 as OEM reserved). Note, /proc/iomem can be consulted for differentiating legacy "Persistent Memory (legacy)" E820_PRAM vs standard "Persistent Memory" E820_PMEM. Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jens Axboe <axboe@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: Christoph Hellwig <hch@lst.de> Tested-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-05-06Merge tag 'efi-urgent' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgent Pull EFI fixes from Matt Fleming: * Avoid garbage names in efivarfs due to buggy firmware by zeroing EFI variable name. (Ross Lagerwall) * Stop erroneously dropping upper 32 bits of boot command line pointer in EFI boot stub and stash them in ext_cmd_line_ptr. (Roy Franz) * Fix double-free bug in error handling code path of EFI runtime map code. (Dan Carpenter) Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-17x86/efi: Store upper bits of command line buffer address in ext_cmd_line_ptrRoy Franz
Until now, the EFI stub was only setting the 32 bit cmd_line_ptr in the setup_header structure, so on 64 bit platforms this could be truncated. This patch adds setting the upper bits of the buffer address in ext_cmd_line_ptr. This case was likely never hit, as the allocation for this buffer is done at the lowest available address. Only x86_64 kernels have this problem, as the 1-1 mapping mandated by EFI ensures that all memory is 32 bit addressable on 32 bit platforms. The EFI stub does not support mixed mode, so the 32 bit kernel on 64 bit firmware case does not need to be handled. Signed-off-by: Roy Franz <roy.franz@linaro.org> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-04-13Merge branch 'x86-boot-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot changes from Ingo Molnar: "A number of cleanups" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Standardize strcmp() x86/boot/64: Remove pointless early_printk() message x86/boot/video: Move the 'video_segment' variable to video.c
2015-04-03x86/mm/KASLR: Propagate KASLR status to kernel properBorislav Petkov
Commit: e2b32e678513 ("x86, kaslr: randomize module base load address") made module base address randomization unconditional and didn't regard disabled KKASLR due to CONFIG_HIBERNATION and command line option "nokaslr". For more info see (now reverted) commit: f47233c2d34f ("x86/mm/ASLR: Propagate base load address calculation") In order to propagate KASLR status to kernel proper, we need a single bit in boot_params.hdr.loadflags and we've chosen bit 1 thus leaving the top-down allocated bits for bits supposed to be used by the bootloader. Originally-From: Jiri Kosina <jkosina@suse.cz> Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-02x86/asm/boot/64: Use __BOOT_TSS instead of literal $0x20Denys Vlasenko
__BOOT_TSS = (GDT_ENTRY_BOOT_TSS * 8) GDT_ENTRY_BOOT_TSS = (GDT_ENTRY_BOOT_CS + 2) GDT_ENTRY_BOOT_CS = 2 (2 + 2) * 8 = 4 * 8 = 32 = 0x20 No code changes. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Borislav Petkov <bp@suse.de> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1427899858-7165-2-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23Merge tag 'v4.0-rc5' into x86/asm, to resolve conflictsIngo Molnar
Conflicts: arch/x86/kernel/entry_64.S Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23x86/boot: Standardize strcmp()Arjun Sreedharan
strcmp() is always expected to return 0 when arguments are equal, negative when its first argument @str1 is less than its second argument @str2 and a positive value otherwise. Previously strcmp("a", "b") returned 1. Now it gives -1, as it is supposed to. Until now this bug never triggered, because all uses for strcmp() in the boot code tested for nonzero: triton:~/tip> git grep strcmp arch/x86/boot/ arch/x86/boot/boot.h:int strcmp(const char *str1, const char *str2); arch/x86/boot/edd.c: if (!strcmp(eddarg, "skipmbr") || !strcmp(eddarg, "skip")) { arch/x86/boot/edd.c: else if (!strcmp(eddarg, "off")) arch/x86/boot/edd.c: else if (!strcmp(eddarg, "on")) should in the future strcmp() be used in a comparative way in the boot code, it might have led to (not so subtle) bugs. Signed-off-by: Arjun Sreedharan <arjun024@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1426520267-1803-1-git-send-email-arjun024@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-16Revert "x86/mm/ASLR: Propagate base load address calculation"Borislav Petkov
This reverts commit: f47233c2d34f ("x86/mm/ASLR: Propagate base load address calculation") The main reason for the revert is that the new boot flag does not work at all currently, and in order to make this work, we need non-trivial changes to the x86 boot code which we didn't manage to get done in time for merging. And even if we did, they would've been too risky so instead of rushing things and break booting 4.1 on boxes left and right, we will be very strict and conservative and will take our time with this to fix and test it properly. Reported-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Baoquan He <bhe@redhat.com> Cc: H. Peter Anvin <hpa@linux.intel.com Cc: Jiri Kosina <jkosina@suse.cz> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Junjie Mao <eternal.n08@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt.fleming@intel.com> Link: http://lkml.kernel.org/r/20150316100628.GD22995@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04Merge tag 'v4.0-rc2' into x86/asm, to refresh the treeIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-21Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull misc x86 fixes from Ingo Molnar: "This contains: - EFI fixes - a boot printout fix - ASLR/kASLR fixes - intel microcode driver fixes - other misc fixes Most of the linecount comes from an EFI revert" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/ASLR: Avoid PAGE_SIZE redefinition for UML subarch x86/microcode/intel: Handle truncated microcode images more robustly x86/microcode/intel: Guard against stack overflow in the loader x86, mm/ASLR: Fix stack randomization on 64-bit systems x86/mm/init: Fix incorrect page size in init_memory_mapping() printks x86/mm/ASLR: Propagate base load address calculation Documentation/x86: Fix path in zero-page.txt x86/apic: Fix the devicetree build in certain configs Revert "efi/libstub: Call get_memory_map() to obtain map and desc sizes" x86/efi: Avoid triple faults during EFI mixed mode calls
2015-02-19Merge branch 'tip-x86-kaslr' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp into x86/urgent Pull ASLR and kASLR fixes from Borislav Petkov: - Add a global flag announcing KASLR state so that relevant code can do informed decisions based on its setting. (Jiri Kosina) - Fix a stack randomization entropy decrease bug. (Hector Marco-Gisbert) Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-19x86/mm/ASLR: Propagate base load address calculationJiri Kosina
Commit: e2b32e678513 ("x86, kaslr: randomize module base load address") makes the base address for module to be unconditionally randomized in case when CONFIG_RANDOMIZE_BASE is defined and "nokaslr" option isn't present on the commandline. This is not consistent with how choose_kernel_location() decides whether it will randomize kernel load base. Namely, CONFIG_HIBERNATION disables kASLR (unless "kaslr" option is explicitly specified on kernel commandline), which makes the state space larger than what module loader is looking at. IOW CONFIG_HIBERNATION && CONFIG_RANDOMIZE_BASE is a valid config option, kASLR wouldn't be applied by default in that case, but module loader is not aware of that. Instead of fixing the logic in module.c, this patch takes more generic aproach. It introduces a new bootparam setup data_type SETUP_KASLR and uses that to pass the information whether kaslr has been applied during kernel decompression, and sets a global 'kaslr_enabled' variable accordingly, so that any kernel code (module loading, livepatching, ...) can make decisions based on its value. x86 module loader is converted to make use of this flag. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Kees Cook <keescook@chromium.org> Cc: "H. Peter Anvin" <hpa@linux.intel.com> Link: https://lkml.kernel.org/r/alpine.LNX.2.00.1502101411280.10719@pobox.suse.cz [ Always dump correct kaslr status when panicking ] Signed-off-by: Borislav Petkov <bp@suse.de>
2015-02-19x86/asm/boot: Use already defined KEEP_SEGMENTS macro in head_{32,64}.SAlexander Kuleshov
There is already defined macro KEEP_SEGMENTS in <asm/bootparam.h>, let's use it instead of hardcoded constants. Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1424331298-7456-1-git-send-email-kuleshovmail@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-19x86/boot/video: Move the 'video_segment' variable to video.cAlexander Kuleshov
video.c is the only real user of the 'video_segment' variable, so move it to video.c and make it static. Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Martin Mares <mj@ucw.cz> Link: http://lkml.kernel.org/r/1422123092-28750-1-git-send-email-kuleshovmail@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-18Merge tag 'efi-urgent' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgent Pull EFI fixes from Matt Fleming: " - Leave a valid 64-bit IDT installed during runtime EFI mixed mode calls to avoid triple faults if an NMI/MCE is received. - Revert Ard's change to the libstub get_memory_map() that went into the v3.20 merge window because it causes boot regressions on Qemu and Xen. " Signed-off-by: Ingo Molnar <mingo@kernel.org>