diff options
| -rw-r--r-- | tools/power/x86/turbostat/turbostat.c | 53 |
1 files changed, 41 insertions, 12 deletions
diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c index 5b1b807265a1..6f29fc11fde6 100644 --- a/tools/power/x86/turbostat/turbostat.c +++ b/tools/power/x86/turbostat/turbostat.c @@ -38,6 +38,8 @@ #include <ctype.h> #include <sched.h> #include <cpuid.h> +#include <linux/capability.h> +#include <errno.h> char *proc_stat = "/proc/stat"; unsigned int interval_sec = 5; /* set with -i interval_sec */ @@ -251,15 +253,13 @@ int get_msr(int cpu, off_t offset, unsigned long long *msr) sprintf(pathname, "/dev/cpu/%d/msr", cpu); fd = open(pathname, O_RDONLY); if (fd < 0) - return -1; + err(-1, "%s open failed, try chown or chmod +r /dev/cpu/*/msr, or run as root", pathname); retval = pread(fd, msr, sizeof *msr, offset); close(fd); - if (retval != sizeof *msr) { - fprintf(stderr, "%s offset 0x%llx read failed\n", pathname, (unsigned long long)offset); - return -1; - } + if (retval != sizeof *msr) + err(-1, "%s offset 0x%llx read failed", pathname, (unsigned long long)offset); return 0; } @@ -1462,10 +1462,40 @@ void check_dev_msr() "Try \"# modprobe msr\""); } -void check_super_user() +void check_permissions() { - if (getuid() != 0) - errx(-6, "must be root"); + struct __user_cap_header_struct cap_header_data; + cap_user_header_t cap_header = &cap_header_data; + struct __user_cap_data_struct cap_data_data; + cap_user_data_t cap_data = &cap_data_data; + extern int capget(cap_user_header_t hdrp, cap_user_data_t datap); + int do_exit = 0; + + /* check for CAP_SYS_RAWIO */ + cap_header->pid = getpid(); + cap_header->version = _LINUX_CAPABILITY_VERSION; + if (capget(cap_header, cap_data) < 0) + err(-6, "capget(2) failed"); + + if ((cap_data->effective & (1 << CAP_SYS_RAWIO)) == 0) { + do_exit++; + warnx("capget(CAP_SYS_RAWIO) failed," + " try \"# setcap cap_sys_rawio=ep %s\"", progname); + } + + /* test file permissions */ + if (euidaccess("/dev/cpu/0/msr", R_OK)) { + do_exit++; + warn("/dev/cpu/0/msr open failed, try chown or chmod +r /dev/cpu/*/msr"); + } + + /* if all else fails, thell them to be root */ + if (do_exit) + if (getuid() != 0) + warnx("Or simply run as root"); + + if (do_exit) + exit(-6); } int has_nehalem_turbo_ratio_limit(unsigned int family, unsigned int model) @@ -2299,10 +2329,9 @@ void setup_all_buffers(void) void turbostat_init() { - check_cpuid(); - check_dev_msr(); - check_super_user(); + check_permissions(); + check_cpuid(); setup_all_buffers(); @@ -2441,7 +2470,7 @@ int main(int argc, char **argv) cmdline(argc, argv); if (verbose) - fprintf(stderr, "turbostat v3.7 Feb 6, 2014" + fprintf(stderr, "turbostat v3.8 14-Aug 2014" " - Len Brown <lenb@kernel.org>\n"); turbostat_init(); |