[3.16.y-ckt stable] Patch "perf: Handle compat ioctl" has been added to staging queue
Luis Henriques
luis.henriques at canonical.com
Mon Nov 24 15:07:16 UTC 2014
This is a note to let you know that I have just added a patch titled
perf: Handle compat ioctl
to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree
which can be found at:
http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue
This patch is scheduled to be released in version 3.16.7-ckt2.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Luis
------
>From 5420043cd672531aa91f87ab8e20fb44c99867cf Mon Sep 17 00:00:00 2001
From: Pawel Moll <pawel.moll at arm.com>
Date: Fri, 13 Jun 2014 16:03:32 +0100
Subject: perf: Handle compat ioctl
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 at arm.com>
Signed-off-by: Pawel Moll <pawel.moll at arm.com>
Signed-off-by: Peter Zijlstra <peterz at infradead.org>
Cc: Arnaldo Carvalho de Melo <acme at kernel.org>
Cc: Jiri Olsa <jolsa at redhat.com>
Link: http://lkml.kernel.org/r/1402671812-9078-1-git-send-email-pawel.moll@arm.com
Signed-off-by: Ingo Molnar <mingo at kernel.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
kernel/events/core.c | 23 ++++++++++++++++++++++-
1 file changed, 22 insertions(+), 1 deletion(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 5dfa199971d2..6bc75223aaa7 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -41,6 +41,7 @@
#include <linux/cgroup.h>
#include <linux/module.h>
#include <linux/mman.h>
+#include <linux/compat.h>
#include "internal.h"
@@ -3747,6 +3748,26 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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;
@@ -4252,7 +4273,7 @@ static const struct file_operations perf_fops = {
.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,
};
--
2.1.0
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