From: Stefan Raspl <stefan.raspl@xxxxxxxxxx>
Te checks for debugfs assumed that debugfs is always mounted at
/sys/kernel/debug - which is likely, but not guaranteed. This is addressed
by checking /proc/mounts for the actual location.
Furthermore, when debugfs was mounted, but the kvm module not loaded, a
misleading error pointing towards debugfs not present was given.
To reproduce,
(a) run kvm_stat with debugfs mounted at a place different from
/sys/kernel/debug
(b) run kvm_stat with debugfs mounted but kvm module not loaded
Signed-off-by: Stefan Raspl <raspl@xxxxxxxxxxxxxxxxxx>
---
tools/kvm/kvm_stat/kvm_stat | 40 ++++++++++++++++++++++++++--------------
1 file changed, 26 insertions(+), 14 deletions(-)
diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat
index e50b68342668..f7ae08dae9cd 100755
--- a/tools/kvm/kvm_stat/kvm_stat
+++ b/tools/kvm/kvm_stat/kvm_stat
@@ -331,9 +331,6 @@ class perf_event_attr(ctypes.Structure):
PERF_TYPE_TRACEPOINT = 2
PERF_FORMAT_GROUP = 1 << 3
-PATH_DEBUGFS_TRACING = '/sys/kernel/debug/tracing'
-PATH_DEBUGFS_KVM = '/sys/kernel/debug/kvm'
-
class Group(object):
"""Represents a perf event group."""
@@ -1543,17 +1540,6 @@ Press any other key to refresh statistics immediately.
def check_access(options):
"""Exits if the current user can't access all needed directories."""
- if not os.path.exists('/sys/kernel/debug'):
- sys.stderr.write('Please enable CONFIG_DEBUG_FS in your kernel.')
- sys.exit(1)
-
- if not os.path.exists(PATH_DEBUGFS_KVM):
- sys.stderr.write("Please make sure, that debugfs is mounted and "
- "readable by the current user:\n"
- "('mount -t debugfs debugfs /sys/kernel/debug')\n"
- "Also ensure, that the kvm modules are loaded.\n")
- sys.exit(1)
-
if not os.path.exists(PATH_DEBUGFS_TRACING) and (options.tracepoints or
not options.debugfs):
sys.stderr.write("Please enable CONFIG_TRACING in your kernel "
@@ -1571,7 +1557,33 @@ def check_access(options):
return options
+def assign_globals():
+ global PATH_DEBUGFS_KVM
+ global PATH_DEBUGFS_TRACING
+
+ debugfs = ''
+ for line in file('/proc/mounts'):
+ if line.split(' ')[0] == 'debugfs':
+ debugfs = line.split(' ')[1]
+ break
+ if debugfs == '':
+ sys.stderr.write("Please make sure that CONFIG_DEBUG_FS is enabled in "
+ "your kernel, mounted and\nreadable by the current "
+ "user:\n"
+ "('mount -t debugfs debugfs /sys/kernel/debug')\n")
+ sys.exit(1)
+
+ PATH_DEBUGFS_KVM = os.path.join(debugfs, 'kvm')
+ PATH_DEBUGFS_TRACING = os.path.join(debugfs, 'tracing')
+
+ if not os.path.exists(PATH_DEBUGFS_KVM):
+ sys.stderr.write("Please make sure that CONFIG_KVM is enabled in "
+ "your kernel and that the modules are loaded.\n")
+ sys.exit(1)
+
+
def main():
+ assign_globals()
options = get_options()
options = check_access(options)
--
2.13.5
