The following commit has been merged into the perf/core branch of tip: Commit-ID: 8859aedefefe7eeea5e67968b7fe39c828d589a0 Gitweb: https://git.kernel.org/tip/8859aedefefe7eeea5e67968b7fe39c828d589a0 Author: Igor Lubashev <ilubashe@xxxxxxxxxx> AuthorDate: Mon, 26 Aug 2019 21:39:15 -04:00 Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> CommitterDate: Wed, 28 Aug 2019 17:19:19 -03:00 perf symbols: Use CAP_SYSLOG with kptr_restrict checks The kernel is using CAP_SYSLOG capability instead of uid==0 and euid==0 when checking kptr_restrict. Make perf do the same. Also, the kernel is a more restrictive than "no restrictions" in case of kptr_restrict==0, so add the same logic to perf. Signed-off-by: Igor Lubashev <ilubashe@xxxxxxxxxx> Tested-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx> Cc: James Morris <jmorris@xxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Suzuki Poulouse <suzuki.poulose@xxxxxxx> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Link: http://lkml.kernel.org/r/1566869956-7154-5-git-send-email-ilubashe@xxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> --- tools/perf/util/symbol.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 4efde78..035f2e7 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -4,6 +4,7 @@ #include <stdlib.h> #include <stdio.h> #include <string.h> +#include <linux/capability.h> #include <linux/kernel.h> #include <linux/mman.h> #include <linux/time64.h> @@ -15,8 +16,10 @@ #include <inttypes.h> #include "annotate.h" #include "build-id.h" +#include "cap.h" #include "util.h" #include "debug.h" +#include "event.h" #include "machine.h" #include "map.h" #include "symbol.h" @@ -2195,13 +2198,19 @@ static bool symbol__read_kptr_restrict(void) char line[8]; if (fgets(line, sizeof(line), fp) != NULL) - value = ((geteuid() != 0) || (getuid() != 0)) ? - (atoi(line) != 0) : - (atoi(line) == 2); + value = perf_cap__capable(CAP_SYSLOG) ? + (atoi(line) >= 2) : + (atoi(line) != 0); fclose(fp); } + /* Per kernel/kallsyms.c: + * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG + */ + if (perf_event_paranoid() > 1 && !perf_cap__capable(CAP_SYSLOG)) + value = true; + return value; }
|