diff options
| -rw-r--r-- | Documentation/sysctl/kernel.txt | 38 | ||||
| -rw-r--r-- | tools/perf/util/evsel.c | 15 |
2 files changed, 34 insertions, 19 deletions
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 9c48b84660f5..8ddf95ff9a9f 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -60,6 +60,7 @@ show up in /proc/sys/kernel: - panic_on_stackoverflow - panic_on_unrecovered_nmi - panic_on_warn +- perf_event_paranoid - pid_max - powersave-nap [ PPC only ] - printk @@ -599,19 +600,6 @@ This file shows up if CONFIG_DEBUG_STACKOVERFLOW is enabled. ============================================================== -panic_on_unrecovered_nmi: - -The default Linux behaviour on an NMI of either memory or unknown is -to continue operation. For many environments such as scientific -computing it is preferable that the box is taken out and the error -dealt with than an uncorrected parity/ECC error get propagated. - -A small number of systems do generate NMI's for bizarre random reasons -such as power management so the default is off. That sysctl works like -the existing panic controls already in that directory. - -============================================================== - panic_on_warn: Calls panic() in the WARN() path when set to 1. This is useful to avoid @@ -649,6 +637,30 @@ allowed to execute. ============================================================== +panic_on_unrecovered_nmi: + +The default Linux behaviour on an NMI of either memory or unknown is +to continue operation. For many environments such as scientific +computing it is preferable that the box is taken out and the error +dealt with than an uncorrected parity/ECC error get propagated. + +A small number of systems do generate NMI's for bizarre random reasons +such as power management so the default is off. That sysctl works like +the existing panic controls already in that directory. + +============================================================== + +perf_event_paranoid: + +Controls use of the performance events system by unprivileged +users (without CAP_SYS_ADMIN). The default value is 1. + + -1: Allow use of (almost) all events by all users +>=0: Disallow raw tracepoint access by users without CAP_IOC_LOCK +>=1: Disallow CPU event access by users without CAP_SYS_ADMIN +>=2: Disallow kernel profiling by users without CAP_SYS_ADMIN + +============================================================== pid_max: diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 397fb4ed3c97..d4913a46ee1c 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2313,12 +2313,15 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target, case EPERM: case EACCES: return scnprintf(msg, size, - "You may not have permission to collect %sstats.\n" - "Consider tweaking /proc/sys/kernel/perf_event_paranoid:\n" - " -1 - Not paranoid at all\n" - " 0 - Disallow raw tracepoint access for unpriv\n" - " 1 - Disallow cpu events for unpriv\n" - " 2 - Disallow kernel profiling for unpriv", + "You may not have permission to collect %sstats.\n\n" + "Consider tweaking /proc/sys/kernel/perf_event_paranoid,\n" + "which controls use of the performance events system by\n" + "unprivileged users (without CAP_SYS_ADMIN).\n\n" + "The default value is 1:\n\n" + " -1: Allow use of (almost) all events by all users\n" + ">= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK\n" + ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n" + ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN", target->system_wide ? "system-wide " : ""); case ENOENT: return scnprintf(msg, size, "The %s event is not supported.", |