3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pawel Moll <pawel.moll@xxxxxxx> commit b3f207855f57b9c8f43a547a801340bb5cbc59e5 upstream. When running a 32-bit userspace on a 64-bit kernel (eg. i386 application on x86_64 kernel or 32-bit arm userspace on arm64 kernel) some of the perf ioctls must be treated with special care, as they have a pointer size encoded in the command. For example, PERF_EVENT_IOC_ID in 32-bit world will be encoded as 0x80042407, but 64-bit kernel will expect 0x80082407. In result the ioctl will fail returning -ENOTTY. This patch solves the problem by adding code fixing up the size as compat_ioctl file operation. Reported-by: Drew Richardson <drew.richardson@xxxxxxx> Signed-off-by: Pawel Moll <pawel.moll@xxxxxxx> Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Link: http://lkml.kernel.org/r/1402671812-9078-1-git-send-email-pawel.moll@xxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: David Ahern <daahern@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/events/core.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -39,6 +39,7 @@ #include <linux/hw_breakpoint.h> #include <linux/mm_types.h> #include <linux/cgroup.h> +#include <linux/compat.h> #include "internal.h" @@ -3693,6 +3694,26 @@ static long perf_ioctl(struct file *file return 0; } +#ifdef CONFIG_COMPAT +static long perf_compat_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + switch (_IOC_NR(cmd)) { + case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): + case _IOC_NR(PERF_EVENT_IOC_ID): + /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ + if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { + cmd &= ~IOCSIZE_MASK; + cmd |= sizeof(void *) << IOCSIZE_SHIFT; + } + break; + } + return perf_ioctl(file, cmd, arg); +} +#else +# define perf_compat_ioctl NULL +#endif + int perf_event_task_enable(void) { struct perf_event *event; @@ -4185,7 +4206,7 @@ static const struct file_operations perf .read = perf_read, .poll = perf_poll, .unlocked_ioctl = perf_ioctl, - .compat_ioctl = perf_ioctl, + .compat_ioctl = perf_compat_ioctl, .mmap = perf_mmap, .fasync = perf_fasync, }; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html