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author | Jan Kiszka <jan.kiszka@siemens.com> | 2015-02-17 22:47:21 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-17 23:34:54 +0100 |
commit | fe7f9ed98dad611ceaf17403f1c5bfd016eadcaa (patch) | |
tree | 469d69f6e6ede329e2e09e513117915aebc7447d /scripts | |
parent | scripts/gdb: add get_gdbserver_type helper (diff) | |
download | linux-fe7f9ed98dad611ceaf17403f1c5bfd016eadcaa.tar.xz linux-fe7f9ed98dad611ceaf17403f1c5bfd016eadcaa.zip |
scripts/gdb: add internal helper and convenience function for per-cpu lookup
This function allows to obtain a per-cpu variable, either of the current
or an explicitly specified CPU.
Note: sparc64 version is untested.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'scripts')
-rw-r--r-- | scripts/gdb/linux/cpus.py | 68 | ||||
-rw-r--r-- | scripts/gdb/vmlinux-gdb.py | 1 |
2 files changed, 69 insertions, 0 deletions
diff --git a/scripts/gdb/linux/cpus.py b/scripts/gdb/linux/cpus.py new file mode 100644 index 000000000000..18337e01ddef --- /dev/null +++ b/scripts/gdb/linux/cpus.py @@ -0,0 +1,68 @@ +# +# gdb helper commands and functions for Linux kernel debugging +# +# per-cpu tools +# +# Copyright (c) Siemens AG, 2011-2013 +# +# Authors: +# Jan Kiszka <jan.kiszka@siemens.com> +# +# This work is licensed under the terms of the GNU GPL version 2. +# + +import gdb + +from linux import tasks, utils + + +MAX_CPUS = 4096 + + +def get_current_cpu(): + if utils.get_gdbserver_type() == utils.GDBSERVER_QEMU: + return gdb.selected_thread().num - 1 + elif utils.get_gdbserver_type() == utils.GDBSERVER_KGDB: + tid = gdb.selected_thread().ptid[2] + if tid > (0x100000000 - MAX_CPUS - 2): + return 0x100000000 - tid - 2 + else: + return tasks.get_thread_info(tasks.get_task_by_pid(tid))['cpu'] + else: + raise gdb.GdbError("Sorry, obtaining the current CPU is not yet " + "supported with this gdb server.") + + +def per_cpu(var_ptr, cpu): + if cpu == -1: + cpu = get_current_cpu() + if utils.is_target_arch("sparc:v9"): + offset = gdb.parse_and_eval( + "trap_block[{0}].__per_cpu_base".format(str(cpu))) + else: + try: + offset = gdb.parse_and_eval( + "__per_cpu_offset[{0}]".format(str(cpu))) + except gdb.error: + # !CONFIG_SMP case + offset = 0 + pointer = var_ptr.cast(utils.get_long_type()) + offset + return pointer.cast(var_ptr.type).dereference() + + +class PerCpu(gdb.Function): + """Return per-cpu variable. + +$lx_per_cpu("VAR"[, CPU]): Return the per-cpu variable called VAR for the +given CPU number. If CPU is omitted, the CPU of the current context is used. +Note that VAR has to be quoted as string.""" + + def __init__(self): + super(PerCpu, self).__init__("lx_per_cpu") + + def invoke(self, var_name, cpu=-1): + var_ptr = gdb.parse_and_eval("&" + var_name.string()) + return per_cpu(var_ptr, cpu) + + +PerCpu() diff --git a/scripts/gdb/vmlinux-gdb.py b/scripts/gdb/vmlinux-gdb.py index 4d7eb2c409aa..48489285f119 100644 --- a/scripts/gdb/vmlinux-gdb.py +++ b/scripts/gdb/vmlinux-gdb.py @@ -27,3 +27,4 @@ else: import linux.modules import linux.dmesg import linux.tasks + import linux.cpus |