Messages in this thread | | | Subject | Re: [PATCH] perf: Handle compat ioctl | From | Pawel Moll <> | Date | Tue, 17 Jun 2014 14:19:03 +0100 |
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On Tue, 2014-06-17 at 13:13 +0100, Peter Zijlstra wrote: > On Fri, Jun 13, 2014 at 04:03:32PM +0100, Pawel Moll wrote: > > 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@arm.com> > > Signed-off-by: Pawel Moll <pawel.moll@arm.com> > > --- > > This gets me (on my favourite x86_64 .config): > > kernel/events/core.c: In function ‘perf_compat_ioctl’: > kernel/events/core.c:3726:32: error: ‘compat_uptr_t’ undeclared (first use in this function) > kernel/events/core.c:3726:32: note: each undeclared identifier is reported only once for each function it appears in
Right, sorry. I've added the size check last minute and haven't re-tested it with x86_64. #include for compat.h was missing (wonder where was it included for arm64 ;-)
Already posted v2.
Pawel
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