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2021-05-07scripts/gdb: document lx_current is only supported by x86Barry Song
Patch series "scripts/gdb: clarify the platforms supporting lx_current and add arm64 support", v2. lx_current depends on per_cpu current_task variable which exists on x86 only. so it actually works on x86 only. the 1st patch documents this clearly; the 2nd patch adds support for arm64. This patch (of 2): x86 is the only architecture which has per_cpu current_task: arch$ git grep current_task | grep -i per_cpu x86/include/asm/current.h:DECLARE_PER_CPU(struct task_struct *, current_task); x86/kernel/cpu/common.c:DEFINE_PER_CPU(struct task_struct *, current_task) ____cacheline_aligned = x86/kernel/cpu/common.c:EXPORT_PER_CPU_SYMBOL(current_task); x86/kernel/cpu/common.c:DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task; x86/kernel/cpu/common.c:EXPORT_PER_CPU_SYMBOL(current_task); x86/kernel/smpboot.c: per_cpu(current_task, cpu) = idle; On other architectures, lx_current() will lead to a python exception: (gdb) p $lx_current().pid Python Exception <class 'gdb.error'> No symbol "current_task" in current context.: Error occurred in Python: No symbol "current_task" in current context. To avoid more people struggling and wasting time in other architectures, document it. Link: https://lkml.kernel.org/r/20210314203444.15188-1-song.bao.hua@hisilicon.com Link: https://lkml.kernel.org/r/20210314203444.15188-2-song.bao.hua@hisilicon.com Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Kieran Bingham <kbingham@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-08Replace HTTP links with HTTPS ones: documentationAlexander A. Klimov
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Link: https://lore.kernel.org/r/20200526060544.25127-1-grandmaster@al2klimov.de Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-07-17docs: disable KASLR when debugging kernelZhouyi Zhou
commit 6807c84652b0 ("x86: Enable KASLR by default") enables KASLR by default on x86. While KASLR will confuse gdb which resolve kernel symbol address from symbol table of vmlinux. We should turn off KASLR for kernel debugging. Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com> Reviewed-by: Kieran Bingham <kbingham@kernel.org> Acked-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-08-18docs: Sphinxify gdb-kernel-debugging.txt and move to dev-toolsJonathan Corbet
Acked-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>