kernel/linux.git/lib, branch v4.19.156

lib/crc32test: remove extra local_irq_disable/enable

2020-11-10T11:35:57+00:00

commit aa4e460f0976351fddd2f5ac6e08b74320c277a1 upstream. Commit 4d004099a668 ("lockdep: Fix lockdep recursion") uncovered the following issue in lib/crc32test reported on s390: BUG: using __this_cpu_read() in preemptible [00000000] code: swapper/0/1 caller is lockdep_hardirqs_on_prepare+0x48/0x270 CPU: 6 PID: 1 Comm: swapper/0 Not tainted 5.9.0-next-20201015-15164-g03d992bd2de6 #19 Hardware name: IBM 3906 M04 704 (LPAR) Call Trace: lockdep_hardirqs_on_prepare+0x48/0x270 trace_hardirqs_on+0x9c/0x1b8 crc32_test.isra.0+0x170/0x1c0 crc32test_init+0x1c/0x40 do_one_initcall+0x40/0x130 do_initcalls+0x126/0x150 kernel_init_freeable+0x1f6/0x230 kernel_init+0x22/0x150 ret_from_fork+0x24/0x2c no locks held by swapper/0/1. Remove extra local_irq_disable/local_irq_enable helpers calls. Fixes: 5fb7f87408f1 ("lib: add module support to crc32 tests") Signed-off-by: Vasily Gorbik Signed-off-by: Andrew Morton Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Greg Kroah-Hartman Link: https://lkml.kernel.org/r/patch.git-4369da00c06e.your-ad-here.call-01602859837-ext-1679@work.hours Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

Fonts: Replace discarded const qualifier

2020-11-10T11:35:57+00:00

commit 9522750c66c689b739e151fcdf895420dc81efc0 upstream. Commit 6735b4632def ("Fonts: Support FONT_EXTRA_WORDS macros for built-in fonts") introduced the following error when building rpc_defconfig (only this build appears to be affected): `acorndata_8x8' referenced in section `.text' of arch/arm/boot/compressed/ll_char_wr.o: defined in discarded section `.data' of arch/arm/boot/compressed/font.o `acorndata_8x8' referenced in section `.data.rel.ro' of arch/arm/boot/compressed/font.o: defined in discarded section `.data' of arch/arm/boot/compressed/font.o make[3]: *** [/scratch/linux/arch/arm/boot/compressed/Makefile:191: arch/arm/boot/compressed/vmlinux] Error 1 make[2]: *** [/scratch/linux/arch/arm/boot/Makefile:61: arch/arm/boot/compressed/vmlinux] Error 2 make[1]: *** [/scratch/linux/arch/arm/Makefile:317: zImage] Error 2 The .data section is discarded at link time. Reinstating acorndata_8x8 as const ensures it is still available after linking. Do the same for the other 12 built-in fonts as well, for consistency purposes. Cc: Cc: Russell King Reviewed-by: Greg Kroah-Hartman Fixes: 6735b4632def ("Fonts: Support FONT_EXTRA_WORDS macros for built-in fonts") Signed-off-by: Lee Jones Co-developed-by: Peilin Ye Signed-off-by: Peilin Ye Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20201102183242.2031659-1-yepeilin.cs@gmail.com Signed-off-by: Greg Kroah-Hartman

sgl_alloc_order: fix memory leak

2020-11-05T10:08:45+00:00

[ Upstream commit b2a182a40278bc5849730e66bca01a762188ed86 ] sgl_alloc_order() can fail when 'length' is large on a memory constrained system. When order > 0 it will potentially be making several multi-page allocations with the later ones more likely to fail than the earlier one. So it is important that sgl_alloc_order() frees up any pages it has obtained before returning NULL. In the case when order > 0 it calls the wrong free page function and leaks. In testing the leak was sufficient to bring down my 8 GiB laptop with OOM. Reviewed-by: Bart Van Assche Signed-off-by: Douglas Gilbert Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

lib/crc32.c: fix trivial typo in preprocessor condition

2020-10-30T09:38:21+00:00

[ Upstream commit 904542dc56524f921a6bab0639ff6249c01e775f ] Whether crc32_be needs a lookup table is chosen based on CRC_LE_BITS. Obviously, the _be function should be governed by the _BE_ define. This probably never pops up as it's hard to come up with a configuration where CRC_BE_BITS isn't the same as CRC_LE_BITS and as nobody is using bitwise CRC anyway. Fixes: 46c5801eaf86 ("crc32: bolt on crc32c") Signed-off-by: Tobias Jordan Signed-off-by: Andrew Morton Cc: Krzysztof Kozlowski Cc: Jonathan Corbet Cc: Mauro Carvalho Chehab Link: https://lkml.kernel.org/r/20200923182122.GA3338@agrajag.zerfleddert.de Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

Fonts: Support FONT_EXTRA_WORDS macros for built-in fonts

2020-10-14T08:31:21+00:00

commit 6735b4632def0640dbdf4eb9f99816aca18c4f16 upstream. syzbot has reported an issue in the framebuffer layer, where a malicious user may overflow our built-in font data buffers. In order to perform a reliable range check, subsystems need to know `FONTDATAMAX` for each built-in font. Unfortunately, our font descriptor, `struct console_font` does not contain `FONTDATAMAX`, and is part of the UAPI, making it infeasible to modify it. For user-provided fonts, the framebuffer layer resolves this issue by reserving four extra words at the beginning of data buffers. Later, whenever a function needs to access them, it simply uses the following macros: Recently we have gathered all the above macros to . Let us do the same thing for built-in fonts, prepend four extra words (including `FONTDATAMAX`) to their data buffers, so that subsystems can use these macros for all fonts, no matter built-in or user-provided. This patch depends on patch "fbdev, newport_con: Move FONT_EXTRA_WORDS macros into linux/font.h". Cc: stable@vger.kernel.org Link: https://syzkaller.appspot.com/bug?id=08b8be45afea11888776f897895aef9ad1c3ecfd Signed-off-by: Peilin Ye Reviewed-by: Greg Kroah-Hartman Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/ef18af00c35fb3cc826048a5f70924ed6ddce95b.1600953813.git.yepeilin.cs@gmail.com Signed-off-by: Greg Kroah-Hartman

random32: Restore __latent_entropy attribute on net_rand_state

2020-10-07T06:00:08+00:00

[ Upstream commit 09a6b0bc3be793ca8cba580b7992d73e9f68f15d ] Commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity") broke compilation and was temporarily fixed by Linus in 83bdc7275e62 ("random32: remove net_rand_state from the latent entropy gcc plugin") by entirely moving net_rand_state out of the things handled by the latent_entropy GCC plugin. From what I understand when reading the plugin code, using the __latent_entropy attribute on a declaration was the wrong part and simply keeping the __latent_entropy attribute on the variable definition was the correct fix. Fixes: 83bdc7275e62 ("random32: remove net_rand_state from the latent entropy gcc plugin") Acked-by: Willy Tarreau Cc: Emese Revfy Signed-off-by: Thibaut Sautereau Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

lib/string.c: implement stpcpy

2020-10-01T11:14:25+00:00

commit 1e1b6d63d6340764e00356873e5794225a2a03ea upstream. LLVM implemented a recent "libcall optimization" that lowers calls to `sprintf(dest, "%s", str)` where the return value is used to `stpcpy(dest, str) - dest`. This generally avoids the machinery involved in parsing format strings. `stpcpy` is just like `strcpy` except it returns the pointer to the new tail of `dest`. This optimization was introduced into clang-12. Implement this so that we don't observe linkage failures due to missing symbol definitions for `stpcpy`. Similar to last year's fire drill with: commit 5f074f3e192f ("lib/string.c: implement a basic bcmp") The kernel is somewhere between a "freestanding" environment (no full libc) and "hosted" environment (many symbols from libc exist with the same type, function signature, and semantics). As Peter Anvin notes, there's not really a great way to inform the compiler that you're targeting a freestanding environment but would like to opt-in to some libcall optimizations (see pr/47280 below), rather than opt-out. Arvind notes, -fno-builtin-* behaves slightly differently between GCC and Clang, and Clang is missing many __builtin_* definitions, which I consider a bug in Clang and am working on fixing. Masahiro summarizes the subtle distinction between compilers justly: To prevent transformation from foo() into bar(), there are two ways in Clang to do that; -fno-builtin-foo, and -fno-builtin-bar. There is only one in GCC; -fno-buitin-foo. (Any difference in that behavior in Clang is likely a bug from a missing __builtin_* definition.) Masahiro also notes: We want to disable optimization from foo() to bar(), but we may still benefit from the optimization from foo() into something else. If GCC implements the same transform, we would run into a problem because it is not -fno-builtin-bar, but -fno-builtin-foo that disables that optimization. In this regard, -fno-builtin-foo would be more future-proof than -fno-built-bar, but -fno-builtin-foo is still potentially overkill. We may want to prevent calls from foo() being optimized into calls to bar(), but we still may want other optimization on calls to foo(). It seems that compilers today don't quite provide the fine grain control over which libcall optimizations pseudo-freestanding environments would prefer. Finally, Kees notes that this interface is unsafe, so we should not encourage its use. As such, I've removed the declaration from any header, but it still needs to be exported to avoid linkage errors in modules. Reported-by: Sami Tolvanen Suggested-by: Andy Lavr Suggested-by: Arvind Sankar Suggested-by: Joe Perches Suggested-by: Kees Cook Suggested-by: Masahiro Yamada Suggested-by: Rasmus Villemoes Signed-off-by: Nick Desaulniers Signed-off-by: Andrew Morton Tested-by: Nathan Chancellor Cc: Link: https://lkml.kernel.org/r/20200914161643.938408-1-ndesaulniers@google.com Link: https://bugs.llvm.org/show_bug.cgi?id=47162 Link: https://bugs.llvm.org/show_bug.cgi?id=47280 Link: https://github.com/ClangBuiltLinux/linux/issues/1126 Link: https://man7.org/linux/man-pages/man3/stpcpy.3.html Link: https://pubs.opengroup.org/onlinepubs/9699919799/functions/stpcpy.html Link: https://reviews.llvm.org/D85963 Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

test_kmod: avoid potential double free in trigger_config_run_type()

2020-08-21T09:05:38+00:00

[ Upstream commit 0776d1231bec0c7ab43baf440a3f5ef5f49dd795 ] Reset the member "test_fs" of the test configuration after a call of the function "kfree_const" to a null pointer so that a double memory release will not be performed. Fixes: d9c6a72d6fa2 ("kmod: add test driver to stress test the module loader") Signed-off-by: Tiezhu Yang Signed-off-by: Luis Chamberlain Signed-off-by: Andrew Morton Acked-by: Luis Chamberlain Cc: Alexei Starovoitov Cc: Al Viro Cc: Christian Brauner Cc: Chuck Lever Cc: David Howells Cc: David S. Miller Cc: Greg Kroah-Hartman Cc: Jakub Kicinski Cc: James Morris Cc: Jarkko Sakkinen Cc: J. Bruce Fields Cc: Jens Axboe Cc: Josh Triplett Cc: Kees Cook Cc: Lars Ellenberg Cc: Nikolay Aleksandrov Cc: Philipp Reisner Cc: Roopa Prabhu Cc: "Serge E. Hallyn" Cc: Sergei Trofimovich Cc: Sergey Kvachonok Cc: Shuah Khan Cc: Tony Vroon Cc: Christoph Hellwig Link: http://lkml.kernel.org/r/20200610154923.27510-4-mcgrof@kernel.org Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

dyndbg: fix a BUG_ON in ddebug_describe_flags

2020-08-19T06:14:53+00:00

[ Upstream commit f678ce8cc3cb2ad29df75d8824c74f36398ba871 ] ddebug_describe_flags() currently fills a caller provided string buffer, after testing its size (also passed) in a BUG_ON. Fix this by replacing them with a known-big-enough string buffer wrapped in a struct, and passing that instead. Also simplify ddebug_describe_flags() flags parameter from a struct to a member in that struct, and hoist the member deref up to the caller. This makes the function reusable (soon) where flags are unpacked. Acked-by: Signed-off-by: Jim Cromie Link: https://lore.kernel.org/r/20200719231058.1586423-8-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

random32: remove net_rand_state from the latent entropy gcc plugin

2020-08-07T07:36:20+00:00

commit 83bdc7275e6206f560d247be856bceba3e1ed8f2 upstream. It turns out that the plugin right now ends up being really unhappy about the change from 'static' to 'extern' storage that happened in commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity"). This is probably a trivial fix for the latent_entropy plugin, but for now, just remove net_rand_state from the list of things the plugin worries about. Reported-by: Stephen Rothwell Cc: Emese Revfy Cc: Kees Cook Cc: Willy Tarreau Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman