user/sven/linux.git/include/linux/crash_core.h, branch v6.7.9

Merge tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-11-03T06:53:31Z

Pull non-MM updates from Andrew Morton: "As usual, lots of singleton and doubleton patches all over the tree and there's little I can say which isn't in the individual changelogs. The lengthier patch series are - 'kdump: use generic functions to simplify crashkernel reservation in arch', from Baoquan He. This is mainly cleanups and consolidation of the 'crashkernel=' kernel parameter handling - After much discussion, David Laight's 'minmax: Relax type checks in min() and max()' is here. Hopefully reduces some typecasting and the use of min_t() and max_t() - A group of patches from Oleg Nesterov which clean up and slightly fix our handling of reads from /proc/PID/task/... and which remove task_struct.thread_group" * tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (64 commits) scripts/gdb/vmalloc: disable on no-MMU scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=n .mailmap: add address mapping for Tomeu Vizoso mailmap: update email address for Claudiu Beznea tools/testing/selftests/mm/run_vmtests.sh: lower the ptrace permissions .mailmap: map Benjamin Poirier's address scripts/gdb: add lx_current support for riscv ocfs2: fix a spelling typo in comment proc: test ProtectionKey in proc-empty-vm test proc: fix proc-empty-vm test with vsyscall fs/proc/base.c: remove unneeded semicolon do_io_accounting: use sig->stats_lock do_io_accounting: use __for_each_thread() ocfs2: replace BUG_ON() at ocfs2_num_free_extents() with ocfs2_error() ocfs2: fix a typo in a comment scripts/show_delta: add __main__ judgement before main code treewide: mark stuff as __ro_after_init fs: ocfs2: check status values proc: test /proc/${pid}/statm compiler.h: move __is_constexpr() to compiler.h ...

kexec: Annotate struct crash_mem with __counted_by

2023-10-24T21:09:46Z

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). As found with Coccinelle[1], add __counted_by for struct crash_mem. [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci Cc: Eric Biederman Cc: kexec@lists.infradead.org Acked-by: Baoquan He Link: https://lore.kernel.org/r/20230922175224.work.712-kees@kernel.org Signed-off-by: Kees Cook

crash_core.c: remove unneeded functions

2023-10-04T17:41:58Z

So far, nobody calls functions parse_crashkernel_high() and parse_crashkernel_low(), remove both of them. Link: https://lkml.kernel.org/r/20230914033142.676708-10-bhe@redhat.com Signed-off-by: Baoquan He Reviewed-by: Zhen Lei Cc: Catalin Marinas Cc: Chen Jiahao Signed-off-by: Andrew Morton

crash_core: move crashk_*res definition into crash_core.c

2023-10-04T17:41:58Z

Both crashk_res and crashk_low_res are used to mark the reserved crashkernel regions in iomem_resource tree. And later the generic crashkernel resrvation will be added into crash_core.c. So move crashk_res and crashk_low_res definition into crash_core.c to avoid compiling error if CONFIG_CRASH_CORE=on while CONFIG_KEXEC_CORE is unset. Meanwhile include in if generic reservation is needed. In that case, need be added by ARCH. In asm/crash_core.h, ARCH can provide its own macro definitions to override macros in if needed. Wrap the including into CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION ifdeffery scope to avoid compiling error in other ARCH-es which don't take the generic reservation way yet. Link: https://lkml.kernel.org/r/20230914033142.676708-6-bhe@redhat.com Signed-off-by: Baoquan He Reviewed-by: Zhen Lei Cc: Catalin Marinas Cc: Chen Jiahao Signed-off-by: Andrew Morton

crash_core: add generic function to do reservation

2023-10-04T17:41:58Z

In architecture like x86_64, arm64 and riscv, they have vast virtual address space and usually have huge physical memory RAM. Their crashkernel reservation doesn't have to be limited under 4G RAM, but can be extended to the whole physical memory via crashkernel=,high support. Now add function reserve_crashkernel_generic() to reserve crashkernel memory if users specify any case of kernel pamameters, like crashkernel=xM[@offset] or crashkernel=,high|low. This is preparation to simplify code of crashkernel=,high support in architecutures. Link: https://lkml.kernel.org/r/20230914033142.676708-5-bhe@redhat.com Signed-off-by: Baoquan He Reviewed-by: Zhen Lei Cc: Catalin Marinas Cc: Chen Jiahao Signed-off-by: Andrew Morton

crash_core: change parse_crashkernel() to support crashkernel=,high|low parsing

2023-10-04T17:41:58Z

Now parse_crashkernel() is a real entry point for all kinds of crahskernel parsing on any architecture. And wrap the crahskernel=,high|low handling inside CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION ifdeffery scope. Link: https://lkml.kernel.org/r/20230914033142.676708-4-bhe@redhat.com Signed-off-by: Baoquan He Reviewed-by: Zhen Lei Cc: Catalin Marinas Cc: Chen Jiahao Signed-off-by: Andrew Morton

crash_core: change the prototype of function parse_crashkernel()

2023-10-04T17:41:58Z

Add two parameters 'low_size' and 'high' to function parse_crashkernel(), later crashkernel=,high|low parsing will be added. Make adjustments in all call sites of parse_crashkernel() in arch. Link: https://lkml.kernel.org/r/20230914033142.676708-3-bhe@redhat.com Signed-off-by: Baoquan He Reviewed-by: Zhen Lei Cc: Catalin Marinas Cc: Chen Jiahao Signed-off-by: Andrew Morton

crash: add generic infrastructure for crash hotplug support

2023-08-24T23:25:13Z

To support crash hotplug, a mechanism is needed to update the crash elfcorehdr upon CPU or memory changes (eg. hot un/plug or off/ onlining). The crash elfcorehdr describes the CPUs and memory to be written into the vmcore. To track CPU changes, callbacks are registered with the cpuhp mechanism via cpuhp_setup_state_nocalls(CPUHP_BP_PREPARE_DYN). The crash hotplug elfcorehdr update has no explicit ordering requirement (relative to other cpuhp states), so meets the criteria for utilizing CPUHP_BP_PREPARE_DYN. CPUHP_BP_PREPARE_DYN is a dynamic state and avoids the need to introduce a new state for crash hotplug. Also, CPUHP_BP_PREPARE_DYN is the last state in the PREPARE group, just prior to the STARTING group, which is very close to the CPU starting up in a plug/online situation, or stopping in a unplug/ offline situation. This minimizes the window of time during an actual plug/online or unplug/offline situation in which the elfcorehdr would be inaccurate. Note that for a CPU being unplugged or offlined, the CPU will still be present in the list of CPUs generated by crash_prepare_elf64_headers(). However, there is no need to explicitly omit the CPU, see justification in 'crash: change crash_prepare_elf64_headers() to for_each_possible_cpu()'. To track memory changes, a notifier is registered to capture the memblock MEM_ONLINE and MEM_OFFLINE events via register_memory_notifier(). The CPU callbacks and memory notifiers invoke crash_handle_hotplug_event() which performs needed tasks and then dispatches the event to the architecture specific arch_crash_handle_hotplug_event() to update the elfcorehdr with the current state of CPUs and memory. During the process, the kexec_lock is held. Link: https://lkml.kernel.org/r/20230814214446.6659-3-eric.devolder@oracle.com Signed-off-by: Eric DeVolder Reviewed-by: Sourabh Jain Acked-by: Hari Bathini Acked-by: Baoquan He Cc: Akhil Raj Cc: Bjorn Helgaas Cc: Borislav Petkov (AMD) Cc: Boris Ostrovsky Cc: Dave Hansen Cc: Dave Young Cc: David Hildenbrand Cc: Eric W. Biederman Cc: Greg Kroah-Hartman Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jonathan Corbet Cc: Konrad Rzeszutek Wilk Cc: Mimi Zohar Cc: Naveen N. Rao Cc: Oscar Salvador Cc: "Rafael J. Wysocki" Cc: Sean Christopherson Cc: Takashi Iwai Cc: Thomas Gleixner Cc: Thomas Weißschuh Cc: Valentin Schneider Cc: Vivek Goyal Cc: Vlastimil Babka Signed-off-by: Andrew Morton

crash: move a few code bits to setup support of crash hotplug

2023-08-24T23:25:13Z

Patch series "crash: Kernel handling of CPU and memory hot un/plug", v28. Once the kdump service is loaded, if changes to CPUs or memory occur, either by hot un/plug or off/onlining, the crash elfcorehdr must also be updated. The elfcorehdr describes to kdump the CPUs and memory in the system, and any inaccuracies can result in a vmcore with missing CPU context or memory regions. The current solution utilizes udev to initiate an unload-then-reload of the kdump image (eg. kernel, initrd, boot_params, purgatory and elfcorehdr) by the userspace kexec utility. In the original post I outlined the significant performance problems related to offloading this activity to userspace. This patchset introduces a generic crash handler that registers with the CPU and memory notifiers. Upon CPU or memory changes, from either hot un/plug or off/onlining, this generic handler is invoked and performs important housekeeping, for example obtaining the appropriate lock, and then invokes an architecture specific handler to do the appropriate elfcorehdr update. Note the description in patch 'crash: change crash_prepare_elf64_headers() to for_each_possible_cpu()' and 'x86/crash: optimize CPU changes' that enables further optimizations related to CPU plug/unplug/online/offline performance of elfcorehdr updates. In the case of x86_64, the arch specific handler generates a new elfcorehdr, and overwrites the old one in memory; thus no involvement with userspace needed. To realize the benefits/test this patchset, one must make a couple of minor changes to userspace: - Prevent udev from updating kdump crash kernel on hot un/plug changes. Add the following as the first lines to the RHEL udev rule file /usr/lib/udev/rules.d/98-kexec.rules: # The kernel updates the crash elfcorehdr for CPU and memory changes SUBSYSTEM=="cpu", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" SUBSYSTEM=="memory", ATTRS{crash_hotplug}=="1", GOTO="kdump_reload_end" With this changeset applied, the two rules evaluate to false for CPU and memory change events and thus skip the userspace unload-then-reload of kdump. - Change to the kexec_file_load for loading the kdump kernel: Eg. on RHEL: in /usr/bin/kdumpctl, change to: standard_kexec_args="-p -d -s" which adds the -s to select kexec_file_load() syscall. This kernel patchset also supports kexec_load() with a modified kexec userspace utility. A working changeset to the kexec userspace utility is posted to the kexec-tools mailing list here: http://lists.infradead.org/pipermail/kexec/2023-May/027049.html To use the kexec-tools patch, apply, build and install kexec-tools, then change the kdumpctl's standard_kexec_args to replace the -s with --hotplug. The removal of -s reverts to the kexec_load syscall and the addition of --hotplug invokes the changes put forth in the kexec-tools patch. This patch (of 8): The crash hotplug support leans on the work for the kexec_file_load() syscall. To also support the kexec_load() syscall, a few bits of code need to be move outside of CONFIG_KEXEC_FILE. As such, these bits are moved out of kexec_file.c and into a common location crash_core.c. In addition, struct crash_mem and crash_notes were moved to new locales so that PROC_KCORE, which sets CRASH_CORE alone, builds correctly. No functionality change intended. Link: https://lkml.kernel.org/r/20230814214446.6659-1-eric.devolder@oracle.com Link: https://lkml.kernel.org/r/20230814214446.6659-2-eric.devolder@oracle.com Signed-off-by: Eric DeVolder Reviewed-by: Sourabh Jain Acked-by: Hari Bathini Acked-by: Baoquan He Cc: Akhil Raj Cc: Bjorn Helgaas Cc: Borislav Petkov (AMD) Cc: Boris Ostrovsky Cc: Dave Hansen Cc: Dave Young Cc: David Hildenbrand Cc: Eric W. Biederman Cc: Greg Kroah-Hartman Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jonathan Corbet Cc: Konrad Rzeszutek Wilk Cc: Mimi Zohar Cc: Naveen N. Rao Cc: Oscar Salvador Cc: "Rafael J. Wysocki" Cc: Sean Christopherson Cc: Takashi Iwai Cc: Thomas Gleixner Cc: Thomas Weißschuh Cc: Valentin Schneider Cc: Vivek Goyal Cc: Vlastimil Babka Signed-off-by: Andrew Morton

kdump: use vmlinux_build_id to simplify

2021-07-08T18:48:22Z

We can use the vmlinux_build_id array here now instead of open coding it. This mostly consolidates code. Link: https://lkml.kernel.org/r/20210511003845.2429846-14-swboyd@chromium.org Signed-off-by: Stephen Boyd Cc: Jiri Olsa Cc: Alexei Starovoitov Cc: Jessica Yu Cc: Evan Green Cc: Hsin-Yi Wang Cc: Dave Young Cc: Baoquan He Cc: Vivek Goyal Cc: Andy Shevchenko Cc: Borislav Petkov Cc: Catalin Marinas Cc: Ingo Molnar Cc: Konstantin Khlebnikov Cc: Matthew Wilcox Cc: Petr Mladek Cc: Rasmus Villemoes Cc: Sasha Levin Cc: Sergey Senozhatsky Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds