kernel/linux.git/lib, branch v4.19.135

lib/zlib: remove outdated and incorrect pre-increment optimization

2020-06-25T13:33:02+00:00

[ Upstream commit acaab7335bd6f0c0b54ce3a00bd7f18222ce0f5f ] The zlib inflate code has an old micro-optimization based on the assumption that for pre-increment memory accesses, the compiler will generate code that fits better into the processor's pipeline than what would be generated for post-increment memory accesses. This optimization was already removed in upstream zlib in 2016: https://github.com/madler/zlib/commit/9aaec95e8211 This optimization causes UB according to C99, which says in section 6.5.6 "Additive operators": "If both the pointer operand and the result point to elements of the same array object, or one past the last element of the array object, the evaluation shall not produce an overflow; otherwise, the behavior is undefined". This UB is not only a theoretical concern, but can also cause trouble for future work on compiler-based sanitizers. According to the zlib commit, this optimization also is not optimal anymore with modern compilers. Replace uses of OFF, PUP and UP_UNALIGNED with their definitions in the POSTINC case, and remove the macro definitions, just like in the upstream patch. Signed-off-by: Jann Horn Signed-off-by: Andrew Morton Cc: Mikhail Zaslonko Link: http://lkml.kernel.org/r/20200507123112.252723-1-jannh@google.com Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

lib/mpi: Fix 64-bit MIPS build with Clang

2020-06-22T07:05:14+00:00

[ Upstream commit 18f1ca46858eac22437819937ae44aa9a8f9f2fa ] When building 64r6_defconfig with CONFIG_MIPS32_O32 disabled and CONFIG_CRYPTO_RSA enabled: lib/mpi/generic_mpih-mul1.c:37:24: error: invalid use of a cast in a inline asm context requiring an l-value: remove the cast or build with -fheinous-gnu-extensions umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb); ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/mpi/longlong.h:664:22: note: expanded from macro 'umul_ppmm' : "=d" ((UDItype)(w0)) ~~~~~~~~~~^~~ lib/mpi/generic_mpih-mul1.c:37:13: error: invalid use of a cast in a inline asm context requiring an l-value: remove the cast or build with -fheinous-gnu-extensions umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb); ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/mpi/longlong.h:668:22: note: expanded from macro 'umul_ppmm' : "=d" ((UDItype)(w1)) ~~~~~~~~~~^~~ 2 errors generated. This special case for umul_ppmm for MIPS64r6 was added in commit bbc25bee37d2b ("lib/mpi: Fix umul_ppmm() for MIPS64r6"), due to GCC being inefficient and emitting a __multi3 intrinsic. There is no such issue with clang; with this patch applied, I can build this configuration without any problems and there are no link errors like mentioned in the commit above (which I can still reproduce with GCC 9.3.0 when that commit is reverted). Only use this definition when GCC is being used. This really should have been caught by commit b0c091ae04f67 ("lib/mpi: Eliminate unused umul_ppmm definitions for MIPS") when I was messing around in this area but I was not testing 64-bit MIPS at the time. Link: https://github.com/ClangBuiltLinux/linux/issues/885 Reported-by: Dmitry Golovin Signed-off-by: Nathan Chancellor Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

lib: Reduce user_access_begin() boundaries in strncpy_from_user() and strnlen_user()

2020-06-22T07:04:59+00:00

commit ab10ae1c3bef56c29bac61e1201c752221b87b41 upstream. The range passed to user_access_begin() by strncpy_from_user() and strnlen_user() starts at 'src' and goes up to the limit of userspace although reads will be limited by the 'count' param. On 32 bits powerpc (book3s/32) access has to be granted for each 256Mbytes segment and the cost increases with the number of segments to unlock. Limit the range with 'count' param. Fixes: 594cc251fdd0 ("make 'user_access_begin()' do 'access_ok()'") Signed-off-by: Christophe Leroy Signed-off-by: Linus Torvalds Signed-off-by: Miles Chen Signed-off-by: Greg Kroah-Hartman

make 'user_access_begin()' do 'access_ok()'

2020-06-22T07:04:58+00:00

commit 594cc251fdd0d231d342d88b2fdff4bc42fb0690 upstream. 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: Linus Torvalds Signed-off-by: Miles Chen Signed-off-by: Greg Kroah-Hartman

ubsan: build ubsan.c more conservatively

2020-05-27T15:37:27+00:00

commit af700eaed0564d5d3963a7a51cb0843629d7fe3d upstream. objtool points out several conditions that it does not like, depending on the combination with other configuration options and compiler variants: stack protector: lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch()+0xbf: call to __stack_chk_fail() with UACCESS enabled lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch_v1()+0xbe: call to __stack_chk_fail() with UACCESS enabled stackleak plugin: lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch()+0x4a: call to stackleak_track_stack() with UACCESS enabled lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch_v1()+0x4a: call to stackleak_track_stack() with UACCESS enabled kasan: lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch()+0x25: call to memcpy() with UACCESS enabled lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch_v1()+0x25: call to memcpy() with UACCESS enabled The stackleak and kasan options just need to be disabled for this file as we do for other files already. For the stack protector, we already attempt to disable it, but this fails on clang because the check is mixed with the gcc specific -fno-conserve-stack option. According to Andrey Ryabinin, that option is not even needed, dropping it here fixes the stackprotector issue. Link: http://lkml.kernel.org/r/20190722125139.1335385-1-arnd@arndb.de Link: https://lore.kernel.org/lkml/20190617123109.667090-1-arnd@arndb.de/t/ Link: https://lore.kernel.org/lkml/20190722091050.2188664-1-arnd@arndb.de/t/ Fixes: d08965a27e84 ("x86/uaccess, ubsan: Fix UBSAN vs. SMAP") Signed-off-by: Arnd Bergmann Reviewed-by: Andrey Ryabinin Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Dmitry Vyukov Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Kees Cook Cc: Matthew Wilcox Cc: Ard Biesheuvel Cc: Andy Shevchenko Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

x86/uaccess, ubsan: Fix UBSAN vs. SMAP

2020-05-27T15:37:27+00:00

commit d08965a27e84ca090b504844d50c24fc98587b11 upstream. UBSAN can insert extra code in random locations; including AC=1 sections. Typically this code is not safe and needs wrapping. So far, only __ubsan_handle_type_mismatch* have been observed in AC=1 sections and therefore only those are annotated. Signed-off-by: Peter Zijlstra (Intel) Cc: Borislav Petkov Cc: Dmitry Vyukov Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar [stable backport: only take the lib/Makefile change to resolve gcc-10 build issues] Signed-off-by: Greg Kroah-Hartman

lib: devres: add a helper function for ioremap_uc

2020-05-10T08:30:11+00:00

[ Upstream commit e537654b7039aacfe8ae629d49655c0e5692ad44 ] Implement a resource managed strongly uncachable ioremap function. Cc: # v4.19+ Tested-by: AceLan Kao Signed-off-by: Tuowen Zhao Acked-by: Mika Westerberg Acked-by: Andy Shevchenko Acked-by: Luis Chamberlain Signed-off-by: Lee Jones Signed-off-by: Sasha Levin

lib/mpi: Fix building for powerpc with clang

2020-05-10T08:30:10+00:00

[ Upstream commit 5990cdee689c6885b27c6d969a3d58b09002b0bc ] 0day reports over and over on an powerpc randconfig with clang: lib/mpi/generic_mpih-mul1.c:37:13: error: invalid use of a cast in a inline asm context requiring an l-value: remove the cast or build with -fheinous-gnu-extensions Remove the superfluous casts, which have been done previously for x86 and arm32 in commit dea632cadd12 ("lib/mpi: fix build with clang") and commit 7b7c1df2883d ("lib/mpi/longlong.h: fix building with 32-bit x86"). Reported-by: kbuild test robot Signed-off-by: Nathan Chancellor Acked-by: Herbert Xu Signed-off-by: Michael Ellerman Link: https://github.com/ClangBuiltLinux/linux/issues/991 Link: https://lore.kernel.org/r/20200413195041.24064-1-natechancellor@gmail.com Signed-off-by: Sasha Levin

lib/raid6: use vdupq_n_u8 to avoid endianness warnings

2020-04-23T08:30:15+00:00

commit 1ad3935b39da78a403e7df7a3813f866c731bc64 upstream. Clang warns: vector initializers are not compatible with NEON intrinsics in big endian mode [-Wnonportable-vector-initialization] While this is usually the case, it's not an issue for this case since we're initializing the uint8x16_t (16x uint8_t's) with the same value. Instead, use vdupq_n_u8 which both compilers lower into a single movi instruction: https://godbolt.org/z/vBrgzt This avoids the static storage for a constant value. Link: https://github.com/ClangBuiltLinux/linux/issues/214 Suggested-by: Nathan Chancellor Reviewed-by: Ard Biesheuvel Signed-off-by: Nick Desaulniers Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

uapi: rename ext2_swab() to swab() and share globally in swab.h

2020-04-17T08:48:43+00:00

[ Upstream commit d5767057c9a76a29f073dad66b7fa12a90e8c748 ] ext2_swab() is defined locally in lib/find_bit.c However it is not specific to ext2, neither to bitmaps. There are many potential users of it, so rename it to just swab() and move to include/uapi/linux/swab.h ABI guarantees that size of unsigned long corresponds to BITS_PER_LONG, therefore drop unneeded cast. Link: http://lkml.kernel.org/r/20200103202846.21616-1-yury.norov@gmail.com Signed-off-by: Yury Norov Cc: Allison Randal Cc: Joe Perches Cc: Thomas Gleixner Cc: William Breathitt Gray Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin