user/sven/linux.git, branch v5.10.178

Linux 5.10.178

2023-04-20T10:10:29Z

Link: https://lore.kernel.org/r/20230418120309.539243408@linuxfoundation.org Tested-by: Florian Fainelli Link: https://lore.kernel.org/r/20230419072207.996418578@linuxfoundation.org Tested-by: Chris Paterson (CIP) Tested-by: Jon Hunter Tested-by: Salvatore Bonaccorso Tested-by: Florian Fainelli Tested-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

sysctl: Fix data-races in proc_dou8vec_minmax().

2023-04-20T10:10:29Z

commit 7dee5d7747a69aa2be41f04c6a7ecfe3ac8cdf18 upstream. A sysctl variable is accessed concurrently, and there is always a chance of data-race. So, all readers and writers need some basic protection to avoid load/store-tearing. This patch changes proc_dou8vec_minmax() to use READ_ONCE() and WRITE_ONCE() internally to fix data-races on the sysctl side. For now, proc_dou8vec_minmax() itself is tolerant to a data-race, but we still need to add annotations on the other subsystem's side. Fixes: cb9444130662 ("sysctl: add proc_dou8vec_minmax()") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

panic, kexec: make __crash_kexec() NMI safe

2023-04-20T10:10:29Z

commit 05c6257433b7212f07a7e53479a8ab038fc1666a upstream. Attempting to get a crash dump out of a debug PREEMPT_RT kernel via an NMI panic() doesn't work. The cause of that lies in the PREEMPT_RT definition of mutex_trylock(): if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES) && WARN_ON_ONCE(!in_task())) return 0; This prevents an nmi_panic() from executing the main body of __crash_kexec() which does the actual kexec into the kdump kernel. The warning and return are explained by: 6ce47fd961fa ("rtmutex: Warn if trylock is called from hard/softirq context") [...] The reasons for this are: 1) There is a potential deadlock in the slowpath 2) Another cpu which blocks on the rtmutex will boost the task which allegedly locked the rtmutex, but that cannot work because the hard/softirq context borrows the task context. Furthermore, grabbing the lock isn't NMI safe, so do away with kexec_mutex and replace it with an atomic variable. This is somewhat overzealous as *some* callsites could keep using a mutex (e.g. the sysfs-facing ones like crash_shrink_memory()), but this has the benefit of involving a single unified lock and preventing any future NMI-related surprises. Tested by triggering NMI panics via: $ echo 1 > /proc/sys/kernel/panic_on_unrecovered_nmi $ echo 1 > /proc/sys/kernel/unknown_nmi_panic $ echo 1 > /proc/sys/kernel/panic $ ipmitool power diag Link: https://lkml.kernel.org/r/20220630223258.4144112-3-vschneid@redhat.com Fixes: 6ce47fd961fa ("rtmutex: Warn if trylock is called from hard/softirq context") Signed-off-by: Valentin Schneider Cc: Arnd Bergmann Cc: Baoquan He Cc: "Eric W . Biederman" Cc: Juri Lelli Cc: Luis Claudio R. Goncalves Cc: Miaohe Lin Cc: Petr Mladek Cc: Sebastian Andrzej Siewior Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Wen Yang Signed-off-by: Greg Kroah-Hartman

kexec: turn all kexec_mutex acquisitions into trylocks

2023-04-20T10:10:29Z

commit 7bb5da0d490b2d836c5218f5186ee588d2145310 upstream. Patch series "kexec, panic: Making crash_kexec() NMI safe", v4. This patch (of 2): Most acquistions of kexec_mutex are done via mutex_trylock() - those were a direct "translation" from: 8c5a1cf0ad3a ("kexec: use a mutex for locking rather than xchg()") there have however been two additions since then that use mutex_lock(): crash_get_memory_size() and crash_shrink_memory(). A later commit will replace said mutex with an atomic variable, and locking operations will become atomic_cmpxchg(). Rather than having those mutex_lock() become while (atomic_cmpxchg(&lock, 0, 1)), turn them into trylocks that can return -EBUSY on acquisition failure. This does halve the printable size of the crash kernel, but that's still neighbouring 2G for 32bit kernels which should be ample enough. Link: https://lkml.kernel.org/r/20220630223258.4144112-1-vschneid@redhat.com Link: https://lkml.kernel.org/r/20220630223258.4144112-2-vschneid@redhat.com Signed-off-by: Valentin Schneider Cc: Arnd Bergmann Cc: "Eric W . Biederman" Cc: Juri Lelli Cc: Luis Claudio R. Goncalves Cc: Miaohe Lin Cc: Petr Mladek Cc: Sebastian Andrzej Siewior Cc: Thomas Gleixner Cc: Baoquan He Signed-off-by: Andrew Morton Signed-off-by: Wen Yang Signed-off-by: Greg Kroah-Hartman

kexec: move locking into do_kexec_load

2023-04-20T10:10:28Z

commit 4b692e861619353ce069e547a67c8d0e32d9ef3d upstream. Patch series "compat: remove compat_alloc_user_space", v5. Going through compat_alloc_user_space() to convert indirect system call arguments tends to add complexity compared to handling the native and compat logic in the same code. This patch (of 6): The locking is the same between the native and compat version of sys_kexec_load(), so it can be done in the common implementation to reduce duplication. Link: https://lkml.kernel.org/r/20210727144859.4150043-1-arnd@kernel.org Link: https://lkml.kernel.org/r/20210727144859.4150043-2-arnd@kernel.org Signed-off-by: Arnd Bergmann Co-developed-by: Eric Biederman Co-developed-by: Christoph Hellwig Acked-by: "Eric W. Biederman" Cc: Catalin Marinas Cc: Will Deacon Cc: Thomas Bogendoerfer Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: "David S. Miller" Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Al Viro Cc: Feng Tang Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Wen Yang Signed-off-by: Greg Kroah-Hartman

riscv: Handle zicsr/zifencei issues between clang and binutils

2023-04-20T10:10:28Z

commit e89c2e815e76471cb507bd95728bf26da7976430 upstream. There are two related issues that appear in certain combinations with clang and GNU binutils. The first occurs when a version of clang that supports zicsr or zifencei via '-march=' [1] (i.e, >= 17.x) is used in combination with a version of GNU binutils that do not recognize zicsr and zifencei in the '-march=' value (i.e., < 2.36): riscv64-linux-gnu-ld: -march=rv64i2p0_m2p0_a2p0_c2p0_zicsr2p0_zifencei2p0: Invalid or unknown z ISA extension: 'zifencei' riscv64-linux-gnu-ld: failed to merge target specific data of file fs/efivarfs/file.o riscv64-linux-gnu-ld: -march=rv64i2p0_m2p0_a2p0_c2p0_zicsr2p0_zifencei2p0: Invalid or unknown z ISA extension: 'zifencei' riscv64-linux-gnu-ld: failed to merge target specific data of file fs/efivarfs/super.o The second occurs when a version of clang that does not support zicsr or zifencei via '-march=' (i.e., <= 16.x) is used in combination with a version of GNU as that defaults to a newer ISA base spec, which requires specifying zicsr and zifencei in the '-march=' value explicitly (i.e, >= 2.38): ../arch/riscv/kernel/kexec_relocate.S: Assembler messages: ../arch/riscv/kernel/kexec_relocate.S:147: Error: unrecognized opcode `fence.i', extension `zifencei' required clang-12: error: assembler command failed with exit code 1 (use -v to see invocation) This is the same issue addressed by commit 6df2a016c0c8 ("riscv: fix build with binutils 2.38") (see [2] for additional information) but older versions of clang miss out on it because the cc-option check fails: clang-12: error: invalid arch name 'rv64imac_zicsr_zifencei', unsupported standard user-level extension 'zicsr' clang-12: error: invalid arch name 'rv64imac_zicsr_zifencei', unsupported standard user-level extension 'zicsr' To resolve the first issue, only attempt to add zicsr and zifencei to the march string when using the GNU assembler 2.38 or newer, which is when the default ISA spec was updated, requiring these extensions to be specified explicitly. LLVM implements an older version of the base specification for all currently released versions, so these instructions are available as part of the 'i' extension. If LLVM's implementation is updated in the future, a CONFIG_AS_IS_LLVM condition can be added to CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI. To resolve the second issue, use version 2.2 of the base ISA spec when using an older version of clang that does not support zicsr or zifencei via '-march=', as that is the spec version most compatible with the one clang/LLVM implements and avoids the need to specify zicsr and zifencei explicitly due to still being a part of 'i'. [1]: https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 [2]: https://lore.kernel.org/ZAxT7T9Xy1Fo3d5W@aurel32.net/ Cc: stable@vger.kernel.org Link: https://github.com/ClangBuiltLinux/linux/issues/1808 Co-developed-by: Conor Dooley Signed-off-by: Conor Dooley Signed-off-by: Nathan Chancellor Acked-by: Conor Dooley Link: https://lore.kernel.org/r/20230313-riscv-zicsr-zifencei-fiasco-v1-1-dd1b7840a551@kernel.org Signed-off-by: Palmer Dabbelt Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

kbuild: check CONFIG_AS_IS_LLVM instead of LLVM_IAS

2023-04-20T10:10:28Z

commit 52cc02b910284d6bddba46cce402044ab775f314 upstream. LLVM_IAS is the user interface to set the -(no-)integrated-as flag, and it should be used only for that purpose. LLVM_IAS is checked in some places to determine the assembler type, but it is not precise. For example, $ make CC=gcc LLVM_IAS=1 ... will use the GNU assembler (i.e. binutils) since LLVM_IAS=1 is effective only when $(CC) is clang. Of course, 'CC=gcc LLVM_IAS=1' is an odd combination, but the build system can be more robust against such insane input. Commit ba64beb17493a ("kbuild: check the minimum assembler version in Kconfig") introduced CONFIG_AS_IS_GNU/LLVM, which is more precise because Kconfig checks the version string from the assembler in use. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers Reviewed-by: Nathan Chancellor [nathan: Backport to 5.10] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

kbuild: Switch to 'f' variants of integrated assembler flag

2023-04-20T10:10:28Z

commit 2185a7e4b0ade86c2c57fc63d4a7535c40254bd0 upstream. It has been brought up a few times in various code reviews that clang 3.5 introduced -f{,no-}integrated-as as the preferred way to enable and disable the integrated assembler, mentioning that -{no-,}integrated-as are now considered legacy flags. Switch the kernel over to using those variants in case there is ever a time where clang decides to remove the non-'f' variants of the flag. Also, fix a typo in a comment ("intergrated" -> "integrated"). Link: https://releases.llvm.org/3.5.0/tools/clang/docs/ReleaseNotes.html#new-compiler-flags Reviewed-by: Nick Desaulniers Signed-off-by: Nathan Chancellor Signed-off-by: Masahiro Yamada [nathan: Backport to 5.10] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

kbuild: check the minimum assembler version in Kconfig

2023-04-20T10:10:28Z

commit ba64beb17493a4bfec563100c86a462a15926f24 upstream. Documentation/process/changes.rst defines the minimum assembler version (binutils version), but we have never checked it in the build time. Kbuild never invokes 'as' directly because all assembly files in the kernel tree are *.S, hence must be preprocessed. I do not expect raw assembly source files (*.s) would be added to the kernel tree. Therefore, we always use $(CC) as the assembler driver, and commit aa824e0c962b ("kbuild: remove AS variable") removed 'AS'. However, we are still interested in the version of the assembler acting behind. As usual, the --version option prints the version string. $ as --version | head -n 1 GNU assembler (GNU Binutils for Ubuntu) 2.35.1 But, we do not have $(AS). So, we can add the -Wa prefix so that $(CC) passes --version down to the backing assembler. $ gcc -Wa,--version | head -n 1 gcc: fatal error: no input files compilation terminated. OK, we need to input something to satisfy gcc. $ gcc -Wa,--version -c -x assembler /dev/null -o /dev/null | head -n 1 GNU assembler (GNU Binutils for Ubuntu) 2.35.1 The combination of Clang and GNU assembler works in the same way: $ clang -no-integrated-as -Wa,--version -c -x assembler /dev/null -o /dev/null | head -n 1 GNU assembler (GNU Binutils for Ubuntu) 2.35.1 Clang with the integrated assembler fails like this: $ clang -integrated-as -Wa,--version -c -x assembler /dev/null -o /dev/null | head -n 1 clang: error: unsupported argument '--version' to option 'Wa,' For the last case, checking the error message is fragile. If the proposal for -Wa,--version support [1] is accepted, this may not be even an error in the future. One easy way is to check if -integrated-as is present in the passed arguments. We did not pass -integrated-as to CLANG_FLAGS before, but we can make it explicit. Nathan pointed out -integrated-as is the default for all of the architectures/targets that the kernel cares about, but it goes along with "explicit is better than implicit" policy. [2] With all this in my mind, I implemented scripts/as-version.sh to check the assembler version in Kconfig time. $ scripts/as-version.sh gcc GNU 23501 $ scripts/as-version.sh clang -no-integrated-as GNU 23501 $ scripts/as-version.sh clang -integrated-as LLVM 0 [1]: https://github.com/ClangBuiltLinux/linux/issues/1320 [2]: https://lore.kernel.org/linux-kbuild/20210307044253.v3h47ucq6ng25iay@archlinux-ax161/ Signed-off-by: Masahiro Yamada Reviewed-by: Nathan Chancellor [nathan: Backport to 5.10. Drop minimum version checking, as it is not required in 5.10] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

coresight-etm4: Fix for() loop drvdata->nr_addr_cmp range bug

2023-04-20T10:10:28Z

commit bf84937e882009075f57fd213836256fc65d96bc upstream. In etm4_enable_hw, fix for() loop range to represent address comparator pairs. Fixes: 2e1cdfe184b5 ("coresight-etm4x: Adding CoreSight ETM4x driver") Cc: stable@vger.kernel.org Signed-off-by: Steve Clevenger Reviewed-by: James Clark Signed-off-by: Suzuki K Poulose Link: https://lore.kernel.org/r/4a4ee61ce8ef402615a4528b21a051de3444fb7b.1677540079.git.scclevenger@os.amperecomputing.com Signed-off-by: Greg Kroah-Hartman