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authorJan Kiszka <jan.kiszka@siemens.com>2015-02-17 13:47:21 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-17 14:34:54 -0800
commitfe7f9ed98dad611ceaf17403f1c5bfd016eadcaa (patch)
tree469d69f6e6ede329e2e09e513117915aebc7447d /scripts/gdb
parentscripts/gdb: add get_gdbserver_type helper (diff)
downloadlinux-dev-fe7f9ed98dad611ceaf17403f1c5bfd016eadcaa.tar.xz
linux-dev-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/gdb')
-rw-r--r--scripts/gdb/linux/cpus.py68
-rw-r--r--scripts/gdb/vmlinux-gdb.py1
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