- 02 Dec, 2022 18 commits
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John Ogness authored
Use srcu console list iteration for console list traversal. Document why the console_lock is still necessary. Note that this is a preparatory change for when console_lock no longer provides synchronization for the console list. Signed-off-by:
John Ogness <john.ogness@linutronix.de> Reviewed-by:
Petr Mladek <pmladek@suse.com> Signed-off-by:
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John Ogness authored
All users of console_is_usable() are SRCU iterators. Use the appropriate wrapper function to locklessly read the flags. Signed-off-by:
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John Ogness authored
Use srcu console list iteration for console list traversal. Document why the console_lock is still necessary. Note that this is a preparatory change for when console_lock no longer provides synchronization for the console list. Signed-off-by:
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John Ogness authored
Guarantee safe iteration of the console list by using SRCU. Note that in the case of a handover, the SRCU read lock is also released. This is documented in the function description and as comments in the code. It is a bit tricky, but this preserves the lockdep lock ordering for the context handing over the console_lock: console_lock() | mutex_acquire(&console_lock_dep_map) <-- console lock | console_unlock() | console_flush_all() | | srcu_read_lock(&console_srcu) <-- srcu lock | | console_emit_next_record() | | | console_lock_spinning_disable_and_check() | | | | srcu_read_unlock(&console_srcu) <-- srcu unlock | | | | mutex_release(&console_lock_dep_map) <-- console unlock Signed-off-by:
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John Ogness authored
Guarantee safe iteration of the console list by using SRCU. Signed-off-by:
Aaron Tomlin <atomlin@atomlin.com> Reviewed-by:
Douglas Anderson <dianders@chromium.org> Signed-off-by:
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John Ogness authored
Rather than using the console_lock to guarantee safe console list traversal, use srcu console list iteration. Signed-off-by:
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John Ogness authored
After switching to SRCU for console list iteration, some readers will begin readings console->flags as a data race. Locklessly reading console->flags provides a consistent value because there is at most one CPU modifying console->flags and that CPU is using only read-modify-write operations. Introduce a wrapper for SRCU iterators to read console flags. Introduce a matching wrapper to write to flags of registered consoles. Writing to flags of registered consoles is synchronized by the console_list_lock. Signed-off-by:
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John Ogness authored
Currently there exist races in register_console(), where the types of registered consoles are checked (without holding the console_lock) and then after acquiring the console_lock, it is assumed that the list has not changed. Also, some code that performs console_unregister() make similar assumptions. It might be possible to fix these races using the console_lock. But it would require a complex analysis of all console drivers to make sure that the console_lock is not taken in match() and setup() callbacks. And we really prefer to split up and reduce the responsibilities of console_lock rather than expand its complexity. Therefore, introduce a new console_list_lock to provide full synchronization for any console list changes. In addition, also use console_list_lock for synchronization of console->flags updates. All flags are either static or modified only during the console registration. There are only two exceptions. The first exception is CON_ENABLED, which is also modified by console_start()/console_stop(). Therefore, these functions must also take the console_list_lock. The second exception is when the flags are modified by the console driver init code before the console is registered. These will be ignored because they are not visible to the rest of the system via the console_drivers list. Note that one of the various responsibilities of the console_lock is also intended to provide console list and console->flags synchronization. Later changes will update call sites relying on the console_lock for these purposes. Once all call sites have been updated, the console_lock will be relieved of synchronizing console_list and console->flags updates. Suggested-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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John Ogness authored
The console_lock is held throughout the start/show/stop procedure to print out device/driver information about all registered consoles. Since the console_lock is being used for multiple reasons, explicitly document these reasons. This will be useful when the console_lock is split into fine-grained locking. Signed-off-by:
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John Ogness authored
show_cons_active() uses the console_lock to gather information on registered consoles. Since the console_lock is being used for multiple reasons, explicitly document these reasons. This will be useful when the console_lock is split into fine-grained locking. Signed-off-by:
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John Ogness authored
kgdboc_earlycon_init() uses the console_lock to ensure that no consoles are unregistered until the kgdboc_earlycon is setup. This is necessary because the trapping of the exit() callback assumes that the exit() callback is not called before the trap is setup. Explicitly document this non-typical console_lock usage. Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by:
Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by:
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John Ogness authored
The initial intention of the UML kmsg_dumper is to dump the kernel buffers to stdout if there is no console available to perform the regular crash output. However, if ttynull was registered as a console, no crash output was seen. Commit e23fe90d ("um: kmsg_dumper: always dump when not tty console") tried to fix this by performing the kmsg_dump unless the stdio console was behind /dev/console or enabled. But this allowed kmsg dumping to occur even if other non-stdio consoles will output the crash output. Also, a console being the driver behind /dev/console has nothing to do with a crash scenario. Restore the initial intention by dumping the kernel buffers to stdout only if a non-ttynull console is registered and enabled. Also add detailed comments so that it is clear why these rules are applied. Signed-off-by:
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John Ogness authored
It used to be that all consoles were synchronized with respect to which message they were printing. After commit a699449b ("printk: refactor and rework printing logic"), all consoles have their own @seq for tracking which message they are on. That commit also changed how the initial sequence number was chosen. Instead of choosing the next non-printed message, it chose the sequence number of the next message that will be added to the ringbuffer. That change created a possibility that a non-boot console taking over for a boot console might skip messages if the boot console was behind and did not have a chance to catch up before being unregistered. Since it is not known which boot console is the same device, flush all consoles and, if necessary, start with the message of the enabled boot console that is the furthest behind. If no boot consoles are enabled, begin with the next message that will be added to the ringbuffer. Also, since boot consoles are meant to be used at boot time, handle them the same as CON_PRINTBUFFER to ensure that no initial messages are skipped. Signed-off-by:
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John Ogness authored
The code to initialize @seq for a new console needs to consider more factors when choosing an initial value. Move the code into a helper function console_init_seq() "as is" so this code can be expanded without causing register_console() to become too long. A later commit will implement the additional code. Signed-off-by:
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John Ogness authored
The @bootcon_enabled and @realcon_enabled local variables actually represent if such console types are registered. In general there has been a confusion about enabled vs. registered. Incorrectly naming such variables promotes such confusion. Rename the variables to _registered. Signed-off-by:
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John Ogness authored
Provide an NMI-safe SRCU protected variant to walk the console list. Note that all console fields are now set before adding the console to the list to avoid the console becoming visible by SCRU readers before being fully initialized. This is a preparatory change for a new console infrastructure which operates independent of the console BKL. Suggested-by:
Miguel Ojeda <ojeda@kernel.org> Reviewed-by:
Paul E. McKenney <paulmck@kernel.org> Reviewed-by:
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Thomas Gleixner authored
Replace the open coded single linked list with a hlist so a conversion to SRCU protected list walks can reuse the existing primitives. Co-developed-by:
Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by:
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Thomas Gleixner authored
Unprotected list walks are not necessarily safe. Signed-off-by:
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- 01 Dec, 2022 1 commit
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Zqiang authored
This commit adds lockdep checks for illegal use of synchronize_srcu() within same-type SRCU read-side critical sections and within normal RCU read-side critical sections. It also makes synchronize_srcu() be a no-op during early boot. These changes bring Tiny synchronize_srcu() into line with both Tree synchronize_srcu() and Tiny synchronize_rcu(). Signed-off-by:
Zqiang <qiang1.zhang@intel.com> Signed-off-by:
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- 29 Nov, 2022 1 commit
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Paul E. McKenney authored
Kernels configured with CONFIG_PRINTK=n and CONFIG_SRCU=n get build failures. This causes trouble for deep embedded systems. But given that there are more than 25 instances of "select SRCU" in the kernel, it is hard to believe that there are many kernels running in production without SRCU. This commit therefore makes SRCU mandatory. The SRCU Kconfig option remains for backwards compatibility, and will be removed when it is no longer used. [ paulmck: Update per kernel test robot feedback. ] Reported-by:
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- 09 Nov, 2022 1 commit
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John Ogness authored
Provide an implementation for debug_lockdep_rcu_enabled() when CONFIG_DEBUG_LOCK_ALLOC is not enabled. This allows code to check if rcu lockdep debugging is available without needing an extra check if CONFIG_DEBUG_LOCK_ALLOC is enabled. Signed-off-by:
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- 21 Oct, 2022 5 commits
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Frederic Weisbecker authored
Currently the NMI safety debugging is only performed on architectures that don't support NMI-safe this_cpu_inc(). Reorder the code so that other architectures like x86 also detect bad uses. [ paulmck: Apply kernel test robot, Stephen Rothwell, and Zqiang feedback. ] Signed-off-by:
Frederic Weisbecker <frederic@kernel.org> Signed-off-by:
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Frederic Weisbecker authored
Tell about the need to protect against concurrent updaters who may overflow the GP counter behind the current update. Reported-by:
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Frederic Weisbecker authored
Using the NMI-unsafe reader API from within an NMI handler is very likely to be buggy for three reasons: 1) NMIs aren't strictly re-entrant (a pending nested NMI will execute at the end of the current one) so it should be fine to use a non-atomic increment here. However, breakpoints can still interrupt NMIs and if a breakpoint callback has a reader on that same ssp, a racy increment can happen. 2) If the only reader site for a given srcu_struct structure is in an NMI handler, then RCU should be used instead of SRCU. 3) Because of the previous reason (2), an srcu_struct structure having an SRCU read side critical section in an NMI handler is likely to have another one from a task context. For all these reasons, warn if an NMI-unsafe reader API is used from an NMI handler. Signed-off-by:
Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by:
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Paul E. McKenney authored
The s390 architecture uses either a cmpxchg loop (old systems) or the laa add-to-memory instruction (new systems) to implement this_cpu_add(), both of which are NMI safe. This means that the old and more-efficient srcu_read_lock() may be used in NMI context, without the need for srcu_read_lock_nmisafe(). Therefore, add the new Kconfig option ARCH_HAS_NMI_SAFE_THIS_CPU_OPS to arch/s390/Kconfig, which will cause NEED_SRCU_NMI_SAFE to be deselected, thus preserving the current srcu_read_lock() behavior. [ paulmck: Apply Christian Borntraeger feedback. ] Link: https://lore.kernel.org/all/20220910221947.171557773@linutronix.de/Suggested-by:
Neeraj Upadhyay <quic_neeraju@quicinc.com> Suggested-by:
Boqun Feng <boqun.feng@gmail.com> Signed-off-by:
Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Ogness <john.ogness@linutronix.de> Cc: Petr Mladek <pmladek@suse.com> Cc: <linux-s390@vger.kernel.org>
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Paul E. McKenney authored
The loongarch architecture uses the atomic read-modify-write amadd instruction to implement this_cpu_add(), which is NMI safe. This means that the old and more-efficient srcu_read_lock() may be used in NMI context, without the need for srcu_read_lock_nmisafe(). Therefore, add the new Kconfig option ARCH_HAS_NMI_SAFE_THIS_CPU_OPS to arch/loongarch/Kconfig, which will cause NEED_SRCU_NMI_SAFE to be deselected, thus preserving the current srcu_read_lock() behavior. Link: https://lore.kernel.org/all/20220910221947.171557773@linutronix.de/Suggested-by:
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- 20 Oct, 2022 5 commits
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Paul E. McKenney authored
The arm64 architecture uses either an LL/SC loop (old systems) or an LSE stadd instruction (new systems) to implement this_cpu_add(), both of which are NMI safe. This means that the old and more-efficient srcu_read_lock() may be used in NMI context, without the need for srcu_read_lock_nmisafe(). Therefore, add the new Kconfig option ARCH_HAS_NMI_SAFE_THIS_CPU_OPS to arch/arm64/Kconfig, which will cause NEED_SRCU_NMI_SAFE to be deselected, thus preserving the current srcu_read_lock() behavior. Link: https://lore.kernel.org/all/20220910221947.171557773@linutronix.de/Suggested-by:
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Paul E. McKenney authored
The x86 architecture uses an add-to-memory instruction to implement this_cpu_add(), which is NMI safe. This means that the old and more-efficient srcu_read_lock() may be used in NMI context, without the need for srcu_read_lock_nmisafe(). Therefore, add the new Kconfig option ARCH_HAS_NMI_SAFE_THIS_CPU_OPS to arch/x86/Kconfig, which will cause NEED_SRCU_NMI_SAFE to be deselected, thus preserving the current srcu_read_lock() behavior. Link: https://lore.kernel.org/all/20220910221947.171557773@linutronix.de/Signed-off-by:
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Paul E. McKenney authored
This commit adds runtime checks to verify that a given srcu_struct uses consistent NMI-safe (or not) read-side primitives globally, but based on the per-CPU data. These global checks are made by the grace-period code that must scan the srcu_data structures anyway, and are done only in kernels built with CONFIG_PROVE_RCU=y. Link: https://lore.kernel.org/all/20220910221947.171557773@linutronix.de/Signed-off-by:
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Paul E. McKenney authored
This commit adds runtime checks to verify that a given srcu_struct uses consistent NMI-safe (or not) read-side primitives on a per-CPU basis. Link: https://lore.kernel.org/all/20220910221947.171557773@linutronix.de/Signed-off-by:
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Paul E. McKenney authored
On strict load-store architectures, the use of this_cpu_inc() by srcu_read_lock() and srcu_read_unlock() is not NMI-safe in TREE SRCU. To see this suppose that an NMI arrives in the middle of srcu_read_lock(), just after it has read ->srcu_lock_count, but before it has written the incremented value back to memory. If that NMI handler also does srcu_read_lock() and srcu_read_lock() on that same srcu_struct structure, then upon return from that NMI handler, the interrupted srcu_read_lock() will overwrite the NMI handler's update to ->srcu_lock_count, but leave unchanged the NMI handler's update by srcu_read_unlock() to ->srcu_unlock_count. This can result in a too-short SRCU grace period, which can in turn result in arbitrary memory corruption. If the NMI handler instead interrupts the srcu_read_unlock(), this can result in eternal SRCU grace periods, which is not much better. This commit therefore creates a pair of new srcu_read_lock_nmisafe() and srcu_read_unlock_nmisafe() functions, which allow SRCU readers in both NMI handlers and in process and IRQ context. It is bad practice to mix the existing and the new _nmisafe() primitives on the same srcu_struct structure. Use one set or the other, not both. Just to underline that "bad practice" point, using srcu_read_lock() at process level and srcu_read_lock_nmisafe() in your NMI handler will not, repeat NOT, work. If you do not immediately understand why this is the case, please review the earlier paragraphs in this commit log. [ paulmck: Apply kernel test robot feedback. ] [ paulmck: Apply feedback from Randy Dunlap. ] [ paulmck: Apply feedback from John Ogness. ] [ paulmck: Apply feedback from Frederic Weisbecker. ] Link: https://lore.kernel.org/all/20220910221947.171557773@linutronix.de/Signed-off-by:
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- 18 Oct, 2022 1 commit
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Paul E. McKenney authored
NMI-safe variants of srcu_read_lock() and srcu_read_unlock() are needed by printk(), which on many architectures entails read-modify-write atomic operations. This commit prepares Tree SRCU for this change by making both ->srcu_lock_count and ->srcu_unlock_count by atomic_long_t. [ paulmck: Apply feedback from John Ogness. ] Link: https://lore.kernel.org/all/20220910221947.171557773@linutronix.de/Signed-off-by:
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- 16 Oct, 2022 8 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/crng/randomLinus Torvalds authored
Pull more random number generator updates from Jason Donenfeld: "This time with some large scale treewide cleanups. The intent of this pull is to clean up the way callers fetch random integers. The current rules for doing this right are: - If you want a secure or an insecure random u64, use get_random_u64() - If you want a secure or an insecure random u32, use get_random_u32() The old function prandom_u32() has been deprecated for a while now and is just a wrapper around get_random_u32(). Same for get_random_int(). - If you want a secure or an insecure random u16, use get_random_u16() - If you want a secure or an insecure random u8, use get_random_u8() - If you want secure or insecure random bytes, use get_random_bytes(). The old function prandom_bytes() has been deprecated for a while now and has long been a wrapper around get_random_bytes() - If you want a non-uniform random u32, u16, or u8 bounded by a certain open interval maximum, use prandom_u32_max() I say "non-uniform", because it doesn't do any rejection sampling or divisions. Hence, it stays within the prandom_*() namespace, not the get_random_*() namespace. I'm currently investigating a "uniform" function for 6.2. We'll see what comes of that. By applying these rules uniformly, we get several benefits: - By using prandom_u32_max() with an upper-bound that the compiler can prove at compile-time is ≤65536 or ≤256, internally get_random_u16() or get_random_u8() is used, which wastes fewer batched random bytes, and hence has higher throughput. - By using prandom_u32_max() instead of %, when the upper-bound is not a constant, division is still avoided, because prandom_u32_max() uses a faster multiplication-based trick instead. - By using get_random_u16() or get_random_u8() in cases where the return value is intended to indeed be a u16 or a u8, we waste fewer batched random bytes, and hence have higher throughput. This series was originally done by hand while I was on an airplane without Internet. Later, Kees and I worked on retroactively figuring out what could be done with Coccinelle and what had to be done manually, and then we split things up based on that. So while this touches a lot of files, the actual amount of code that's hand fiddled is comfortably small" * tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: prandom: remove unused functions treewide: use get_random_bytes() when possible treewide: use get_random_u32() when possible treewide: use get_random_{u8,u16}() when possible, part 2 treewide: use get_random_{u8,u16}() when possible, part 1 treewide: use prandom_u32_max() when possible, part 2 treewide: use prandom_u32_max() when possible, part 1 -
Linus Torvalds authored
Merge tag 'perf-tools-for-v6.1-2-2022-10-16' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux Pull more perf tools updates from Arnaldo Carvalho de Melo: - Use BPF CO-RE (Compile Once, Run Everywhere) to support old kernels when using bperf (perf BPF based counters) with cgroups. - Support HiSilicon PCIe Performance Monitoring Unit (PMU), that monitors bandwidth, latency, bus utilization and buffer occupancy. Documented in Documentation/admin-guide/perf/hisi-pcie-pmu.rst. - User space tasks can migrate between CPUs, so when tracing selected CPUs, system-wide sideband is still needed, fix it in the setup of Intel PT on hybrid systems. - Fix metricgroups title message in 'perf list', it should state that the metrics groups are to be used with the '-M' option, not '-e'. - Sync the msr-index.h copy with the kernel sources, adding support for using "AMD64_TSC_RATIO" in filter expressions in 'perf trace' as well as decoding it when printing the MSR tracepoint arguments. - Fix program header size and alignment when generating a JIT ELF in 'perf inject'. - Add multiple new Intel PT 'perf test' entries, including a jitdump one. - Fix the 'perf test' entries for 'perf stat' CSV and JSON output when running on PowerPC due to an invalid topology number in that arch. - Fix the 'perf test' for arm_coresight failures on the ARM Juno system. - Fix the 'perf test' attr entry for PERF_FORMAT_LOST, adding this option to the or expression expected in the intercepted perf_event_open() syscall. - Add missing condition flags ('hs', 'lo', 'vc', 'vs') for arm64 in the 'perf annotate' asm parser. - Fix 'perf mem record -C' option processing, it was being chopped up when preparing the underlying 'perf record -e mem-events' and thus being ignored, requiring using '-- -C CPUs' as a workaround. - Improvements and tidy ups for 'perf test' shell infra. - Fix Intel PT information printing segfault in uClibc, where a NULL format was being passed to fprintf. * tag 'perf-tools-for-v6.1-2-2022-10-16' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (23 commits) tools arch x86: Sync the msr-index.h copy with the kernel sources perf auxtrace arm64: Add support for parsing HiSilicon PCIe Trace packet perf auxtrace arm64: Add support for HiSilicon PCIe Tune and Trace device driver perf auxtrace arm: Refactor event list iteration in auxtrace_record__init() perf tests stat+json_output: Include sanity check for topology perf tests stat+csv_output: Include sanity check for topology perf intel-pt: Fix system_wide dummy event for hybrid perf intel-pt: Fix segfault in intel_pt_print_info() with uClibc perf test: Fix attr tests for PERF_FORMAT_LOST perf test: test_intel_pt.sh: Add 9 tests perf inject: Fix GEN_ELF_TEXT_OFFSET for jit perf test: test_intel_pt.sh: Add jitdump test perf test: test_intel_pt.sh: Tidy some alignment perf test: test_intel_pt.sh: Print a message when skipping kernel tracing perf test: test_intel_pt.sh: Tidy some perf record options perf test: test_intel_pt.sh: Fix return checking again perf: Skip and warn on unknown format 'configN' attrs perf list: Fix metricgroups title message perf mem: Fix -C option behavior for perf mem record perf annotate: Add missing condition flags for arm64 ...
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Linus Torvalds authored
Merge tag 'kbuild-fixes-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - Fix CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y compile error for the combination of Clang >= 14 and GAS <= 2.35. - Drop vmlinux.bz2 from the rpm package as it just annoyingly increased the package size. - Fix modpost error under build environments using musl. - Make *.ll files keep value names for easier debugging - Fix single directory build - Prevent RISC-V from selecting the broken DWARF5 support when Clang and GAS are used together. * tag 'kbuild-fixes-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: lib/Kconfig.debug: Add check for non-constant .{s,u}leb128 support to DWARF5 kbuild: fix single directory build kbuild: add -fno-discard-value-names to cmd_cc_ll_c scripts/clang-tools: Convert clang-tidy args to list modpost: put modpost options before argument kbuild: Stop including vmlinux.bz2 in the rpm's Kconfig.debug: add toolchain checks for DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT Kconfig.debug: simplify the dependency of DEBUG_INFO_DWARF4/5
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git://git.kernel.org/pub/scm/linux/kernel/git/clk/linuxLinus Torvalds authored
Pull more clk updates from Stephen Boyd: "This is the final part of the clk patches for this merge window. The clk rate range series needed another week to fully bake. Maxime fixed the bug that broke clk notifiers and prevented this from being included in the first pull request. He also added a unit test on top to make sure it doesn't break so easily again. The majority of the series fixes up how the clk_set_rate_*() APIs work, particularly around when the rate constraints are dropped and how they move around when reparenting clks. Overall it's a much needed improvement to the clk rate range APIs that used to be pretty broken if you looked sideways. Beyond the core changes there are a few driver fixes for a compilation issue or improper data causing clks to fail to register or have the wrong parents. These are good to get in before the first -rc so that the system actually boots on the affected devices" * tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (31 commits) clk: tegra: Fix Tegra PWM parent clock clk: at91: fix the build with binutils 2.27 clk: qcom: gcc-msm8660: Drop hardcoded fixed board clocks clk: mediatek: clk-mux: Add .determine_rate() callback clk: tests: Add tests for notifiers clk: Update req_rate on __clk_recalc_rates() clk: tests: Add missing test case for ranges clk: qcom: clk-rcg2: Take clock boundaries into consideration for gfx3d clk: Introduce the clk_hw_get_rate_range function clk: Zero the clk_rate_request structure clk: Stop forwarding clk_rate_requests to the parent clk: Constify clk_has_parent() clk: Introduce clk_core_has_parent() clk: Switch from __clk_determine_rate to clk_core_round_rate_nolock clk: Add our request boundaries in clk_core_init_rate_req clk: Introduce clk_hw_init_rate_request() clk: Move clk_core_init_rate_req() from clk_core_round_rate_nolock() to its caller clk: Change clk_core_init_rate_req prototype clk: Set req_rate on reparenting clk: Take into account uncached clocks in clk_set_rate_range() ...
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git://git.samba.org/sfrench/cifs-2.6Linus Torvalds authored
Pull more cifs updates from Steve French: - fix a regression in guest mounts to old servers - improvements to directory leasing (caching directory entries safely beyond the root directory) - symlink improvement (reducing roundtrips needed to process symlinks) - an lseek fix (to problem where some dir entries could be skipped) - improved ioctl for returning more detailed information on directory change notifications - clarify multichannel interface query warning - cleanup fix (for better aligning buffers using ALIGN and round_up) - a compounding fix - fix some uninitialized variable bugs found by Coverity and the kernel test robot * tag '6.1-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6: smb3: improve SMB3 change notification support cifs: lease key is uninitialized in two additional functions when smb1 cifs: lease key is uninitialized in smb1 paths smb3: must initialize two ACL struct fields to zero cifs: fix double-fault crash during ntlmssp cifs: fix static checker warning cifs: use ALIGN() and round_up() macros cifs: find and use the dentry for cached non-root directories also cifs: enable caching of directories for which a lease is held cifs: prevent copying past input buffer boundaries cifs: fix uninitialised var in smb2_compound_op() cifs: improve symlink handling for smb2+ smb3: clarify multichannel warning cifs: fix regression in very old smb1 mounts cifs: fix skipping to incorrect offset in emit_cached_dirents
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Tetsuo Handa authored
This reverts commit 78e5a339 ("cpumask: fix checking valid cpu range"). syzbot is hitting WARN_ON_ONCE(cpu >= nr_cpumask_bits) warning at cpu_max_bits_warn() [1], for commit 78e5a339 ("cpumask: fix checking valid cpu range") is broken. Obviously that patch hits WARN_ON_ONCE() when e.g. reading /proc/cpuinfo because passing "cpu + 1" instead of "cpu" will trivially hit cpu == nr_cpumask_bits condition. Although syzbot found this problem in linux-next.git on 2022/09/27 [2], this problem was not fixed immediately. As a result, that patch was sent to linux.git before the patch author recognizes this problem, and syzbot started failing to test changes in linux.git since 2022/10/10 [3]. Andrew Jones proposed a fix for x86 and riscv architectures [4]. But [2] and [5] indicate that affected locations are not limited to arch code. More delay before we find and fix affected locations, less tested kernel (and more difficult to bisect and fix) before release. We should have inspected and fixed basically all cpumask users before applying that patch. We should not crash kernels in order to ask existing cpumask users to update their code, even if limited to CONFIG_DEBUG_PER_CPU_MAPS=y case. Link: https://syzkaller.appspot.com/bug?extid=d0fd2bf0dd6da72496dd [1] Link: https://syzkaller.appspot.com/bug?extid=21da700f3c9f0bc40150 [2] Link: https://syzkaller.appspot.com/bug?extid=51a652e2d24d53e75734 [3] Link: https://lkml.kernel.org/r/20221014155845.1986223-1-ajones@ventanamicro.com [4] Link: https://syzkaller.appspot.com/bug?extid=4d46c43d81c3bd155060 [5] Reported-by:
Andrew Jones <ajones@ventanamicro.com> Reported-by: syzbot+d0fd2bf0dd6da72496dd@syzkaller.appspotmail.com Signed-off-by:
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Yury Norov <yury.norov@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Nathan Chancellor authored
When building with a RISC-V kernel with DWARF5 debug info using clang and the GNU assembler, several instances of the following error appear: /tmp/vgettimeofday-48aa35.s:2963: Error: non-constant .uleb128 is not supported Dumping the .s file reveals these .uleb128 directives come from .debug_loc and .debug_ranges: .Ldebug_loc0: .byte 4 # DW_LLE_offset_pair .uleb128 .Lfunc_begin0-.Lfunc_begin0 # starting offset .uleb128 .Ltmp1-.Lfunc_begin0 # ending offset .byte 1 # Loc expr size .byte 90 # DW_OP_reg10 .byte 0 # DW_LLE_end_of_list .Ldebug_ranges0: .byte 4 # DW_RLE_offset_pair .uleb128 .Ltmp6-.Lfunc_begin0 # starting offset .uleb128 .Ltmp27-.Lfunc_begin0 # ending offset .byte 4 # DW_RLE_offset_pair .uleb128 .Ltmp28-.Lfunc_begin0 # starting offset .uleb128 .Ltmp30-.Lfunc_begin0 # ending offset .byte 0 # DW_RLE_end_of_list There is an outstanding binutils issue to support a non-constant operand to .sleb128 and .uleb128 in GAS for RISC-V but there does not appear to be any movement on it, due to concerns over how it would work with linker relaxation. To avoid these build errors, prevent DWARF5 from being selected when using clang and an assembler that does not have support for these symbol deltas, which can be easily checked in Kconfig with as-instr plus the small test program from the dwz test suite from the binutils issue. Link: https://sourceware.org/bugzilla/show_bug.cgi?id=27215 Link: https://github.com/ClangBuiltLinux/linux/issues/1719Signed-off-by:Nathan Chancellor <nathan@kernel.org> Reviewed-by:
Nick Desaulniers <ndesaulniers@google.com> Signed-off-by:
Masahiro Yamada <masahiroy@kernel.org>
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