kernel/linux.git/scripts/gdb/linux, branch v6.19.11

scripts/gdb/symbols: make BPF debug info available to GDB

2025-11-20T22:03:42+00:00

One can debug BPF programs with QEMU gdbstub by setting a breakpoint on bpf_prog_kallsyms_add(), waiting for a hit with a matching aux.name, and then setting a breakpoint on bpf_func. This is tedious, error-prone, and also lacks line numbers. Automate this in a way similar to the existing support for modules in lx-symbols. Enumerate and monitor changes to both BPF kallsyms and JITed progs. For each ksym, generate and compile a synthetic .s file containing the name, code, and size. In addition, if this ksym is also a prog, and not a trampoline, add line number information. Ensure that this is a no-op if the kernel is built without BPF support or if "as" is missing. In theory the "as" dependency may be dropped by generating the synthetic .o file manually, but this is too much complexity for too little benefit. Now one can debug BPF progs out of the box like this: (gdb) lx-symbols -bpf (gdb) b bpf_prog_4e612a6a881a086b_arena_list_add Breakpoint 2 (bpf_prog_4e612a6a881a086b_arena_list_add) pending. # ./test_progs -t arena_list Thread 4 hit Breakpoint 2, bpf_prog_4e612a6a881a086b_arena_list_add () at linux/tools/testing/selftests/bpf/progs/arena_list.c:51 51 list_head = &global_head; (gdb) n bpf_prog_4e612a6a881a086b_arena_list_add () at linux/tools/testing/selftests/bpf/progs/arena_list.c:53 53 for (i = zero; i < cnt && can_loop; i++) { This also works for subprogs. Link: https://lkml.kernel.org/r/20251106124600.86736-3-iii@linux.ibm.com Signed-off-by: Ilya Leoshkevich Cc: Alexander Gordeev Cc: Alexei Starovoitov Cc: Andrii Nakryiko Cc: Daniel Borkman Cc: Heiko Carstens Cc: Jan Kiszka Cc: Kieran Bingham Cc: Vasily Gorbik Signed-off-by: Andrew Morton

scripts/gdb/radix-tree: add lx-radix-tree-command

2025-11-20T22:03:42+00:00

Patch series "scripts/gdb/symbols: make BPF debug info available to GDB", v2. This series greatly simplifies debugging BPF progs when using QEMU gdbstub by providing symbol names, sizes, and line numbers to GDB. Patch 1 adds radix tree iteration, which is necessary for parsing prog_idr. Patch 2 is the actual implementation; its description contains some details on how to use this. This patch (of 2): Add a function and a command to iterate over radix tree contents. Duplicate the C implementation in Python, but drop support for tagging. Link: https://lkml.kernel.org/r/20251106124600.86736-1-iii@linux.ibm.com Link: https://lkml.kernel.org/r/20251106124600.86736-2-iii@linux.ibm.com Signed-off-by: Ilya Leoshkevich Cc: Alexander Gordeev Cc: Alexei Starovoitov Cc: Andrii Nakryiko Cc: Daniel Borkman Cc: Heiko Carstens Cc: Jan Kiszka Cc: Kieran Bingham Cc: Vasily Gorbik Signed-off-by: Andrew Morton

hrtimer: Remove hrtimer_clock_base:: Get_time

2025-09-09T10:27:18+00:00

The get_time() callbacks always need to match the bases clockid. Instead of maintaining that association twice in hrtimer_bases, use a helper. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/all/20250821-hrtimer-cleanup-get_time-v2-8-3ae822e5bfbd@linutronix.de

Merge tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-08-03T23:23:09+00:00

Pull non-MM updates from Andrew Morton: "Significant patch series in this pull request: - "squashfs: Remove page->mapping references" (Matthew Wilcox) gets us closer to being able to remove page->mapping - "relayfs: misc changes" (Jason Xing) does some maintenance and minor feature addition work in relayfs - "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches us from static preallocation of the kdump crashkernel's working memory over to dynamic allocation. So the difficulty of a-priori estimation of the second kernel's needs is removed and the first kernel obtains extra memory - "generalize panic_print's dump function to be used by other kernel parts" (Feng Tang) implements some consolidation and rationalization of the various ways in which a failing kernel splats information at the operator * tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits) tools/getdelays: add backward compatibility for taskstats version kho: add test for kexec handover delaytop: enhance error logging and add PSI feature description samples: Kconfig: fix spelling mistake "instancess" -> "instances" fat: fix too many log in fat_chain_add() scripts/spelling.txt: add notifer||notifier to spelling.txt xen/xenbus: fix typo "notifer" net: mvneta: fix typo "notifer" drm/xe: fix typo "notifer" cxl: mce: fix typo "notifer" KVM: x86: fix typo "notifer" MAINTAINERS: add maintainers for delaytop ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below() ucount: fix atomic_long_inc_below() argument type kexec: enable CMA based contiguous allocation stackdepot: make max number of pools boot-time configurable lib/xxhash: remove unused functions init/Kconfig: restore CONFIG_BROKEN help text lib/raid6: update recov_rvv.c zero page usage docs: update docs after introducing delaytop ...

Merge tag 's390-6.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2025-07-30T03:17:08+00:00

Pull s390 updates from Alexander Gordeev: - Standardize on the __ASSEMBLER__ macro that is provided by GCC and Clang compilers and replace __ASSEMBLY__ with __ASSEMBLER__ in both uapi and non-uapi headers - Explicitly include in architecture and driver files which contain an EXPORT_SYMBOL() and remove the include from the files which do not contain the EXPORT_SYMBOL() - Use the full title of "z/Architecture Principles of Operation" manual and the name of a section where facility bits are listed - Use -D__DISABLE_EXPORTS for files in arch/s390/boot to avoid unnecessary slowing down of the build and confusing external kABI tools that process symtypes data - Print additional unrecoverable machine check information to make the root cause analysis easier - Move cmpxchg_user_key() handling to uaccess library code, since the generated code is large anyway and there is no benefit if it is inlined - Fix a problem when cmpxchg_user_key() is executing a code with a non-default key: if a system is IPL-ed with "LOAD NORMAL", and the previous system used storage keys where the fetch-protection bit was set for some pages, and the cmpxchg_user_key() is located within such page, a protection exception happens - Either the external call or emergency signal order is used to send an IPI to a remote CPU. Use the external order only, since it is at least as good and sometimes even better, than the emergency signal - In case of an early crash the early program check handler prints more or less random value of the last breaking event address, since it is not initialized properly. Copy the last breaking event address from the lowcore to pt_regs to address this - During STP synchronization check udelay() can not be used, since the first CPU modifies tod_clock_base and get_tod_clock_monotonic() might return a non-monotonic time. Instead, busy-loop on other CPUs, while the the first CPU actually handles the synchronization operation - When debugging the early kernel boot using QEMU with the -S flag and GDB attached, skip the decompressor and start directly in kernel - Rename PAI Crypto event 4210 according to z16 and z17 "z/Architecture Principles of Operation" manual - Remove the in-kernel time steering support in favour of the new s390 PTP driver, which allows the kernel clock steered more precisely - Remove a possible false-positive warning in pte_free_defer(), which could be triggered in a valid case KVM guest process is initializing * tag 's390-6.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (29 commits) s390/mm: Remove possible false-positive warning in pte_free_defer() s390/stp: Default to enabled s390/stp: Remove leap second support s390/time: Remove in-kernel time steering s390/sclp: Use monotonic clock in sclp_sync_wait() s390/smp: Use monotonic clock in smp_emergency_stop() s390/time: Use monotonic clock in get_cycles() s390/pai_crypto: Rename PAI Crypto event 4210 scripts/gdb/symbols: make lx-symbols skip the s390 decompressor s390/boot: Introduce jump_to_kernel() function s390/stp: Remove udelay from stp_sync_clock() s390/early: Copy last breaking event address to pt_regs s390/smp: Remove conditional emergency signal order code usage s390/uaccess: Merge cmpxchg_user_key() inline assemblies s390/uaccess: Prevent kprobes on cmpxchg_user_key() functions s390/uaccess: Initialize code pages executed with non-default access key s390/skey: Provide infrastructure for executing with non-default access key s390/uaccess: Make cmpxchg_user_key() library code s390/page: Add memory clobber to page_set_storage_key() s390/page: Cleanup page_set_storage_key() inline assemblies ...

scripts/gdb/symbols: make lx-symbols skip the s390 decompressor

2025-07-10T12:42:10+00:00

When one starts QEMU with the -S flag and attaches GDB, the kernel is not yet loaded, and the current instruction is an entry point to the decompressor. In case the intention is to debug the early kernel boot, and not the decompressor, e.g., put a breakpoint on some kernel function and see all the invocations, one has to skip the decompressor. There are many ways to do this, and so far people wrote private scripts or memorized certain command sequences. Make it work out of the box like this: $ gdb -ex 'target remote :6812' -ex 'source vmlinux-gdb.py' vmlinux Remote debugging using :6812 0x0000000000010000 in ?? () (gdb) lx-symbols loading vmlinux (gdb) x/i $pc => 0x3ffe0100000 : lghi %r2,0 Implement this by reading the address of the jump_to_kernel() function from the lowcore, and step until DAT is turned on. Signed-off-by: Ilya Leoshkevich Acked-by: Jan Kiszka Tested-by: Alexander Gordeev Link: https://lore.kernel.org/r/20250625154220.75300-3-iii@linux.ibm.com Signed-off-by: Alexander Gordeev

scripts: gdb: move MNT_* constants to gdb-parsed

2025-07-10T05:57:54+00:00

Since these are now no longer defines, but in an enum. Link: https://lkml.kernel.org/r/20250618134629.25700-2-johannes@sipsolutions.net Fixes: 101f2bbab541 ("fs: convert mount flags to enum") Reviewed-by: Benjamin Berg Signed-off-by: Johannes Berg Cc: Jan Kiszka Cc: Kieran Bingham Cc: Stephen Brennan Signed-off-by: Andrew Morton

scripts: gdb: vfs: support external dentry names

2025-07-10T04:07:54+00:00

d_shortname of struct dentry only reserves D_NAME_INLINE_LEN characters and contains garbage for longer names. Use d_name instead, which always references the valid name. Link: https://lore.kernel.org/all/20250525213709.878287-2-illia@yshyn.com/ Link: https://lkml.kernel.org/r/20250629003811.2420418-1-illia@yshyn.com Fixes: 79300ac805b6 ("scripts/gdb: fix dentry_name() lookup") Signed-off-by: Illia Ostapyshyn Tested-by: Florian Fainelli Reviewed-by: Florian Fainelli Cc: Al Viro Cc: Christian Brauner Cc: Jan Kara Cc: Jan Kiszka Cc: Kieran Bingham Cc: Signed-off-by: Andrew Morton

scripts/gdb: de-reference per-CPU MCE interrupts

2025-07-10T04:07:53+00:00

The per-CPU MCE interrupts are looked up by reference and need to be de-referenced before printing, otherwise we print the addresses of the variables instead of their contents: MCE: 18379471554386948492 Machine check exceptions MCP: 18379471554386948488 Machine check polls The corrected output looks like this instead now: MCE: 0 Machine check exceptions MCP: 1 Machine check polls Link: https://lkml.kernel.org/r/20250625021109.1057046-1-florian.fainelli@broadcom.com Link: https://lkml.kernel.org/r/20250624030020.882472-1-florian.fainelli@broadcom.com Fixes: b0969d7687a7 ("scripts/gdb: print interrupts") Signed-off-by: Florian Fainelli Cc: Jan Kiszka Cc: Kieran Bingham Cc: Signed-off-by: Andrew Morton

scripts/gdb: fix interrupts.py after maple tree conversion

2025-07-10T04:07:53+00:00

In commit 721255b9826b ("genirq: Use a maple tree for interrupt descriptor management"), the irq_desc_tree was replaced with a sparse_irqs tree using a maple tree structure. Since the script looked for the irq_desc_tree symbol which is no longer available, no interrupts would be printed and the script output would not be useful anymore. In addition to looking up the correct symbol (sparse_irqs), a new module (mapletree.py) is added whose mtree_load() implementation is largely copied after the C version and uses the same variable and intermediate function names wherever possible to ensure that both the C and Python version be updated in the future. This restores the scripts' output to match that of /proc/interrupts. Link: https://lkml.kernel.org/r/20250625021020.1056930-1-florian.fainelli@broadcom.com Fixes: 721255b9826b ("genirq: Use a maple tree for interrupt descriptor management") Signed-off-by: Florian Fainelli Cc: Jan Kiszka Cc: Kieran Bingham Cc: Shanker Donthineni Cc: Thomas Gleinxer Cc: Signed-off-by: Andrew Morton