user/sven/linux.git/scripts/Makefile.lib, branch v4.4.194

kbuild: fix asm-offset generation to work with clang

2018-11-27T15:07:57Z

commit cf0c3e68aa81f992b0301f62e341b710d385bf68 upstream. KBuild abuses the asm statement to write to a file and clang chokes about these invalid asm statements. Hack it even more by fooling this is actual valid asm code. [masahiro: Import Jeroen's work for U-Boot: http://patchwork.ozlabs.org/patch/375026/ Tweak sed script a little to avoid garbage '#' for GCC case, like #define NR_PAGEFLAGS 23 /* __NR_PAGEFLAGS # */ ] Signed-off-by: Jeroen Hofstee Signed-off-by: Masahiro Yamada Reviewed-by: Matthias Kaehlcke Tested-by: Matthias Kaehlcke Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

kbuild: consolidate redundant sed script ASM offset generation

2018-11-27T15:07:57Z

commit 7dd47b95b0f54f2057d40af6e66d477e3fe95d13 upstream. This part ended up in redundant code after touched by multiple people. [1] Commit 3234282f33b2 ("x86, asm: Fix CFI macro invocations to deal with shortcomings in gas") added parentheses for defined expressions to support old gas for x86. [2] Commit a22dcdb0032c ("x86, asm: Fix ancient-GAS workaround") split the pattern into two to avoid parentheses for non-numeric expressions. [3] Commit 95a2f6f72d37 ("Partially revert patch that encloses asm-offset.h numbers in brackets") removed parentheses from numeric expressions as well because parentheses in MN10300 assembly have a special meaning (pointer access). Apparently, there is a conflict between [1] and [3]. After all, [3] took precedence, and a long time has passed since then. Now, merge the two patterns again because the first one is covered by the other. Signed-off-by: Masahiro Yamada Reviewed-by: Matthias Kaehlcke Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

kbuild: Consolidate header generation from ASM offset information

2018-11-27T15:07:57Z

commit ebf003f0cfb3705e60d40dedc3ec949176c741af upstream. Largely redundant code is used in different places to generate C headers from offset information extracted from assembly language output. Consolidate the code in Makefile.lib and use this instead. Signed-off-by: Matthias Kaehlcke Signed-off-by: Masahiro Yamada Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

kasan: don't emit builtin calls when sanitization is off

2018-08-17T18:56:44Z

commit 0e410e158e5baa1300bdf678cea4f4e0cf9d8b94 upstream. With KASAN enabled the kernel has two different memset() functions, one with KASAN checks (memset) and one without (__memset). KASAN uses some macro tricks to use the proper version where required. For example memset() calls in mm/slub.c are without KASAN checks, since they operate on poisoned slab object metadata. The issue is that clang emits memset() calls even when there is no memset() in the source code. They get linked with improper memset() implementation and the kernel fails to boot due to a huge amount of KASAN reports during early boot stages. The solution is to add -fno-builtin flag for files with KASAN_SANITIZE := n marker. Link: http://lkml.kernel.org/r/8ffecfffe04088c52c42b92739c2bd8a0bcb3f5e.1516384594.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Acked-by: Nick Desaulniers Cc: Masahiro Yamada Cc: Michal Marek Cc: Andrey Ryabinin Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [ Nick : Backported to 4.4 avoiding KUBSAN ] Signed-off-by: Nick Desaulniers Signed-off-by: Greg Kroah-Hartman

kbuild: Handle builtin dtb file names containing hyphens

2018-03-18T10:17:49Z

commit 55fe6da9efba102866e2fb5b40b04b6a4b26c19e upstream. cmd_dt_S_dtb constructs the assembly source to incorporate a devicetree FDT (that is, the .dtb file) as binary data in the kernel image. This assembly source contains labels before and after the binary data. The label names incorporate the file name of the corresponding .dtb file. Hyphens are not legal characters in labels, so .dtb files built into the kernel with hyphens in the file name result in errors like the following: bcm3368-netgear-cvg834g.dtb.S: Assembler messages: bcm3368-netgear-cvg834g.dtb.S:5: Error: : no such section bcm3368-netgear-cvg834g.dtb.S:5: Error: junk at end of line, first unrecognized character is `-' bcm3368-netgear-cvg834g.dtb.S:6: Error: unrecognized opcode `__dtb_bcm3368-netgear-cvg834g_begin:' bcm3368-netgear-cvg834g.dtb.S:8: Error: unrecognized opcode `__dtb_bcm3368-netgear-cvg834g_end:' bcm3368-netgear-cvg834g.dtb.S:9: Error: : no such section bcm3368-netgear-cvg834g.dtb.S:9: Error: junk at end of line, first unrecognized character is `-' Fix this by updating cmd_dt_S_dtb to transform all hyphens from the file name to underscores when constructing the labels. As of v4.16-rc2, 1139 .dts files across ARM64, ARM, MIPS and PowerPC contain hyphens in their names, but the issue only currently manifests on Broadcom MIPS platforms, as that is the only place where such files are built into the kernel. For example when CONFIG_DT_NETGEAR_CVG834G=y, or on BMIPS kernels when the dtbs target is used (in the latter case it admittedly shouldn't really build all the dtb.o files, but thats a separate issue). Fixes: 695835511f96 ("MIPS: BMIPS: rename bcm96358nb4ser to bcm6358-neufbox4-sercom") Signed-off-by: James Hogan Reviewed-by: Frank Rowand Cc: Rob Herring Cc: Michal Marek Cc: Ralf Baechle Cc: Florian Fainelli Cc: Kevin Cernekee Cc: # 4.9+ Signed-off-by: Masahiro Yamada Signed-off-by: Greg Kroah-Hartman

kbuild: Create directory for target DTB

2015-04-03T20:52:28Z

When building specific DTBs out of the kernel tree the vendor subdirs (boot/dts/) are not created, ensure that they are before building the DTB. Signed-off-by: Nathan Rossi Signed-off-by: Michal Simek Acked-by: Will Deacon Signed-off-by: Olof Johansson

kasan: add kernel address sanitizer infrastructure

2015-02-14T05:21:40Z

Kernel Address sanitizer (KASan) is a dynamic memory error detector. It provides fast and comprehensive solution for finding use-after-free and out-of-bounds bugs. KASAN uses compile-time instrumentation for checking every memory access, therefore GCC > v4.9.2 required. v4.9.2 almost works, but has issues with putting symbol aliases into the wrong section, which breaks kasan instrumentation of globals. This patch only adds infrastructure for kernel address sanitizer. It's not available for use yet. The idea and some code was borrowed from [1]. Basic idea: The main idea of KASAN is to use shadow memory to record whether each byte of memory is safe to access or not, and use compiler's instrumentation to check the shadow memory on each memory access. Address sanitizer uses 1/8 of the memory addressable in kernel for shadow memory and uses direct mapping with a scale and offset to translate a memory address to its corresponding shadow address. Here is function to translate address to corresponding shadow address: unsigned long kasan_mem_to_shadow(unsigned long addr) { return (addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET; } where KASAN_SHADOW_SCALE_SHIFT = 3. So for every 8 bytes there is one corresponding byte of shadow memory. The following encoding used for each shadow byte: 0 means that all 8 bytes of the corresponding memory region are valid for access; k (1 <= k <= 7) means that the first k bytes are valid for access, and other (8 - k) bytes are not; Any negative value indicates that the entire 8-bytes are inaccessible. Different negative values used to distinguish between different kinds of inaccessible memory (redzones, freed memory) (see mm/kasan/kasan.h). To be able to detect accesses to bad memory we need a special compiler. Such compiler inserts a specific function calls (__asan_load*(addr), __asan_store*(addr)) before each memory access of size 1, 2, 4, 8 or 16. These functions check whether memory region is valid to access or not by checking corresponding shadow memory. If access is not valid an error printed. Historical background of the address sanitizer from Dmitry Vyukov: "We've developed the set of tools, AddressSanitizer (Asan), ThreadSanitizer and MemorySanitizer, for user space. We actively use them for testing inside of Google (continuous testing, fuzzing, running prod services). To date the tools have found more than 10'000 scary bugs in Chromium, Google internal codebase and various open-source projects (Firefox, OpenSSL, gcc, clang, ffmpeg, MySQL and lots of others): [2] [3] [4]. The tools are part of both gcc and clang compilers. We have not yet done massive testing under the Kernel AddressSanitizer (it's kind of chicken and egg problem, you need it to be upstream to start applying it extensively). To date it has found about 50 bugs. Bugs that we've found in upstream kernel are listed in [5]. We've also found ~20 bugs in out internal version of the kernel. Also people from Samsung and Oracle have found some. [...] As others noted, the main feature of AddressSanitizer is its performance due to inline compiler instrumentation and simple linear shadow memory. User-space Asan has ~2x slowdown on computational programs and ~2x memory consumption increase. Taking into account that kernel usually consumes only small fraction of CPU and memory when running real user-space programs, I would expect that kernel Asan will have ~10-30% slowdown and similar memory consumption increase (when we finish all tuning). I agree that Asan can well replace kmemcheck. We have plans to start working on Kernel MemorySanitizer that finds uses of unitialized memory. Asan+Msan will provide feature-parity with kmemcheck. As others noted, Asan will unlikely replace debug slab and pagealloc that can be enabled at runtime. Asan uses compiler instrumentation, so even if it is disabled, it still incurs visible overheads. Asan technology is easily portable to other architectures. Compiler instrumentation is fully portable. Runtime has some arch-dependent parts like shadow mapping and atomic operation interception. They are relatively easy to port." Comparison with other debugging features: ======================================== KMEMCHECK: - KASan can do almost everything that kmemcheck can. KASan uses compile-time instrumentation, which makes it significantly faster than kmemcheck. The only advantage of kmemcheck over KASan is detection of uninitialized memory reads. Some brief performance testing showed that kasan could be x500-x600 times faster than kmemcheck: $ netperf -l 30 MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to localhost (127.0.0.1) port 0 AF_INET Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec no debug: 87380 16384 16384 30.00 41624.72 kasan inline: 87380 16384 16384 30.00 12870.54 kasan outline: 87380 16384 16384 30.00 10586.39 kmemcheck: 87380 16384 16384 30.03 20.23 - Also kmemcheck couldn't work on several CPUs. It always sets number of CPUs to 1. KASan doesn't have such limitation. DEBUG_PAGEALLOC: - KASan is slower than DEBUG_PAGEALLOC, but KASan works on sub-page granularity level, so it able to find more bugs. SLUB_DEBUG (poisoning, redzones): - SLUB_DEBUG has lower overhead than KASan. - SLUB_DEBUG in most cases are not able to detect bad reads, KASan able to detect both reads and writes. - In some cases (e.g. redzone overwritten) SLUB_DEBUG detect bugs only on allocation/freeing of object. KASan catch bugs right before it will happen, so we always know exact place of first bad read/write. [1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel [2] https://code.google.com/p/address-sanitizer/wiki/FoundBugs [3] https://code.google.com/p/thread-sanitizer/wiki/FoundBugs [4] https://code.google.com/p/memory-sanitizer/wiki/FoundBugs [5] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel#Trophies Based on work by Andrey Konovalov. Signed-off-by: Andrey Ryabinin Acked-by: Michal Marek Signed-off-by: Andrey Konovalov Cc: Dmitry Vyukov Cc: Konstantin Serebryany Cc: Dmitry Chernenkov Cc: Yuri Gribov Cc: Konstantin Khlebnikov Cc: Sasha Levin Cc: Christoph Lameter Cc: Joonsoo Kim Cc: Dave Hansen Cc: Andi Kleen Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

dts, kbuild: Factor out dtbs install rules to Makefile.dtbinst

2014-10-21T16:06:58Z

Move dtbs install rules to Makefile.dtbinst. This change is needed to implement support for dts vendor subdirs. The change makes Makefiles easier and smaller as no longer the dtbs_install rule needs to be defined. Another advantage is that install goals are not encoded in targets anymore (%.dtb_dtbinst_). Signed-off-by: Robert Richter

kbuild: handle multi-objs dependency appropriately

2014-08-19T08:26:19Z

The comment in scripts/Makefile.build says as follows: We would rather have a list of rules like foo.o: $(foo-objs) but that's not so easy, so we rather make all composite objects depend on the set of all their parts This commit makes it possible! For example, assume a Makefile like this obj-m = foo.o bar.o foo-objs := foo1.o foo2.o bar-objs := bar1.o bar2.o Without this patch, foo.o depends on all of foo1.o foo2.o bar1.o bar2.o. It looks funny that foo.o is regenerated when bar1.c is updated. Now we can handle the dependency of foo.o and bar.o separately. Signed-off-by: Masahiro Yamada Signed-off-by: Michal Marek

kbuild: trivial - remove trailing spaces

2014-04-30T15:34:32Z

Signed-off-by: Masahiro Yamada Signed-off-by: Michal Marek