linux-dev/arch/sparc/vdso, branch master

treewide: use prandom_u32_max() when possible, part 1

2022-10-11T23:42:55Z

Rather than incurring a division or requesting too many random bytes for the given range, use the prandom_u32_max() function, which only takes the minimum required bytes from the RNG and avoids divisions. This was done mechanically with this coccinelle script: @basic@ expression E; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u64; @@ ( - ((T)get_random_u32() % (E)) + prandom_u32_max(E) | - ((T)get_random_u32() & ((E) - 1)) + prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2) | - ((u64)(E) * get_random_u32() >> 32) + prandom_u32_max(E) | - ((T)get_random_u32() & ~PAGE_MASK) + prandom_u32_max(PAGE_SIZE) ) @multi_line@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; identifier RAND; expression E; @@ - RAND = get_random_u32(); ... when != RAND - RAND %= (E); + RAND = prandom_u32_max(E); // Find a potential literal @literal_mask@ expression LITERAL; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; position p; @@ ((T)get_random_u32()@p & (LITERAL)) // Add one to the literal. @script:python add_one@ literal << literal_mask.LITERAL; RESULT; @@ value = None if literal.startswith('0x'): value = int(literal, 16) elif literal[0] in '123456789': value = int(literal, 10) if value is None: print("I don't know how to handle %s" % (literal)) cocci.include_match(False) elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1: print("Skipping 0x%x for cleanup elsewhere" % (value)) cocci.include_match(False) elif value & (value + 1) != 0: print("Skipping 0x%x because it's not a power of two minus one" % (value)) cocci.include_match(False) elif literal.startswith('0x'): coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1)) else: coccinelle.RESULT = cocci.make_expr("%d" % (value + 1)) // Replace the literal mask with the calculated result. @plus_one@ expression literal_mask.LITERAL; position literal_mask.p; expression add_one.RESULT; identifier FUNC; @@ - (FUNC()@p & (LITERAL)) + prandom_u32_max(RESULT) @collapse_ret@ type T; identifier VAR; expression E; @@ { - T VAR; - VAR = (E); - return VAR; + return E; } @drop_var@ type T; identifier VAR; @@ { - T VAR; ... when != VAR } Reviewed-by: Greg Kroah-Hartman Reviewed-by: Kees Cook Reviewed-by: Yury Norov Reviewed-by: KP Singh Reviewed-by: Jan Kara # for ext4 and sbitmap Reviewed-by: Christoph Böhmwalder # for drbd Acked-by: Jakub Kicinski Acked-by: Heiko Carstens # for s390 Acked-by: Ulf Hansson # for mmc Acked-by: Darrick J. Wong # for xfs Signed-off-by: Jason A. Donenfeld

treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_385.RULE

2022-06-10T12:51:36Z

Based on the normalized pattern: licensed under the gpl v2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference. Reviewed-by: Allison Randal Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

randstruct: Split randstruct Makefile and CFLAGS

2022-05-08T08:33:06Z

To enable the new Clang randstruct implementation[1], move randstruct into its own Makefile and split the CFLAGS from GCC_PLUGINS_CFLAGS into RANDSTRUCT_CFLAGS. [1] https://reviews.llvm.org/D121556 Cc: linux-hardening@vger.kernel.org Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220503205503.3054173-5-keescook@chromium.org

treewide: remove DISABLE_LTO

2020-10-20T15:28:53Z

This change removes all instances of DISABLE_LTO from Makefiles, as they are currently unused, and the preferred method of disabling LTO is to filter out the flags instead. Note added by Masahiro Yamada: DISABLE_LTO was added as preparation for GCC LTO, but GCC LTO was not pulled into the mainline. (https://lkml.org/lkml/2014/4/8/272) Suggested-by: Kees Cook Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Signed-off-by: Masahiro Yamada

kbuild: explicitly specify the build id style

2020-10-09T14:57:30Z

ld's --build-id defaults to "sha1" style, while lld defaults to "fast". The build IDs are very different between the two, which may confuse programs that reference them. Signed-off-by: Bill Wendling Acked-by: David S. Miller Signed-off-by: Masahiro Yamada

kbuild: remove cc-option test of -fno-stack-protector

2020-07-07T02:13:10Z

Some Makefiles already pass -fno-stack-protector unconditionally. For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile. No problem report so far about hard-coding this option. So, we can assume all supported compilers know -fno-stack-protector. GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN) Get rid of cc-option from -fno-stack-protector. Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'. Note: arch/mips/vdso/Makefile adds -fno-stack-protector twice, first unconditionally, and second conditionally. I removed the second one. Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook Acked-by: Ard Biesheuvel Reviewed-by: Nick Desaulniers

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

2020-06-09T16:39:14Z

This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse Signed-off-by: Andrew Morton Reviewed-by: Daniel Jordan Reviewed-by: Laurent Dufour Reviewed-by: Vlastimil Babka Cc: Davidlohr Bueso Cc: David Rientjes Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: John Hubbard Cc: Liam Howlett Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Ying Han Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds

sparc,x86: vdso: remove meaningless undefining CONFIG_OPTIMIZE_INLINING

2020-04-07T17:43:42Z

The code, #undef CONFIG_OPTIMIZE_INLINING, is not working as expected because is parsed before vclock_gettime.c since 28128c61e08e ("kconfig.h: Include compiler types to avoid missed struct attributes"). Since then, is included really early by using the '-include' option. So, you cannot negate the decision of in this way. You can confirm it by checking the pre-processed code, like this: $ make arch/x86/entry/vdso/vdso32/vclock_gettime.i There is no difference with/without CONFIG_CC_OPTIMIZE_FOR_SIZE. It is about two years since 28128c61e08e. Nobody has reported a problem (or, nobody has even noticed the fact that this code is not working). It is ugly and unreliable to attempt to undefine a CONFIG option from C files, and anyway the inlining heuristic is up to the compiler. Just remove the broken code. Signed-off-by: Masahiro Yamada Signed-off-by: Andrew Morton Reviewed-by: Nathan Chancellor Acked-by: Miguel Ojeda Cc: Arnd Bergmann Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Masahiro Yamada Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: David Miller Link: http://lkml.kernel.org/r/20200220110807.32534-1-masahiroy@kernel.org Signed-off-by: Linus Torvalds

.gitignore: add SPDX License Identifier

2020-03-25T10:50:48Z

Add SPDX License Identifier to all .gitignore files. Signed-off-by: Masahiro Yamada Signed-off-by: Greg Kroah-Hartman

kbuild: rename hostprogs-y/always to hostprogs/always-y

2020-02-03T16:53:07Z

In old days, the "host-progs" syntax was used for specifying host programs. It was renamed to the current "hostprogs-y" in 2004. It is typically useful in scripts/Makefile because it allows Kbuild to selectively compile host programs based on the kernel configuration. This commit renames like follows: always -> always-y hostprogs-y -> hostprogs So, scripts/Makefile will look like this: always-$(CONFIG_BUILD_BIN2C) += ... always-$(CONFIG_KALLSYMS) += ... ... hostprogs := $(always-y) $(always-m) I think this makes more sense because a host program is always a host program, irrespective of the kernel configuration. We want to specify which ones to compile by CONFIG options, so always-y will be handier. The "always", "hostprogs-y", "hostprogs-m" will be kept for backward compatibility for a while. Signed-off-by: Masahiro Yamada