Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Thu, 25 May 2017 11:18:02 -0400 Steven Rostedt wrote: > On Thu, 25 May 2017 19:34:43 +0900 > Masami Hiramatsu wrote: > > > > OK, I've ensured that following command hits same BUG. > > > > grep t /proc/kallsyms | cut -f3 -d" " | grep -v .*\\..* |

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Thu, 25 May 2017 11:18:02 -0400 Steven Rostedt wrote: > On Thu, 25 May 2017 19:34:43 +0900 > Masami Hiramatsu wrote: > > > > OK, I've ensured that following command hits same BUG. > > > > grep t /proc/kallsyms | cut -f3 -d" " | grep -v .*\\..* | \ > > head -n 256 | while read i; do echo

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Thu, 25 May 2017 19:34:43 +0900 Masami Hiramatsu wrote: > OK, I've ensured that following command hits same BUG. > > grep t /proc/kallsyms | cut -f3 -d" " | grep -v .*\\..* | \ > head -n 256 | while read i; do echo p $i+5 ; done > > tracing/kprobe_events > > echo 1 >

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Thu, 25 May 2017 19:34:43 +0900 Masami Hiramatsu wrote: > OK, I've ensured that following command hits same BUG. > > grep t /proc/kallsyms | cut -f3 -d" " | grep -v .*\\..* | \ > head -n 256 | while read i; do echo p $i+5 ; done > > tracing/kprobe_events > > echo 1 >

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Thu, 25 May 2017 18:09:10 +0900 Masami Hiramatsu wrote: > On Wed, 24 May 2017 18:25:47 -0400 > Steven Rostedt wrote: > > > On Wed, 24 May 2017 21:13:27 +0200 (CEST) > > Thomas Gleixner wrote: > > > > > > > > Oops: 0003 [#1]

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Thu, 25 May 2017 18:09:10 +0900 Masami Hiramatsu wrote: > On Wed, 24 May 2017 18:25:47 -0400 > Steven Rostedt wrote: > > > On Wed, 24 May 2017 21:13:27 +0200 (CEST) > > Thomas Gleixner wrote: > > > > > > > > Oops: 0003 [#1] SMP > > > > Modules linked in: > > > > CPU: 3 PID: 1 Comm:

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, 24 May 2017 18:25:47 -0400 Steven Rostedt wrote: > On Wed, 24 May 2017 21:13:27 +0200 (CEST) > Thomas Gleixner wrote: > > > > > Oops: 0003 [#1] SMP > > > Modules linked in: > > > CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc2-test+ #42 >

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, 24 May 2017 18:25:47 -0400 Steven Rostedt wrote: > On Wed, 24 May 2017 21:13:27 +0200 (CEST) > Thomas Gleixner wrote: > > > > > Oops: 0003 [#1] SMP > > > Modules linked in: > > > CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc2-test+ #42 > > > Hardware name: MSI

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, 24 May 2017, Steven Rostedt wrote: > The trampolines uses the module allocation, and it appears, that needs > to become rw before freeing again. Indeed. I realized that when enabling more debug options, which led to a reliable triple fault. How intuitive. > I applied this patch, and it

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, 24 May 2017, Steven Rostedt wrote: > The trampolines uses the module allocation, and it appears, that needs > to become rw before freeing again. Indeed. I realized that when enabling more debug options, which led to a reliable triple fault. How intuitive. > I applied this patch, and it

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, May 24, 2017 at 06:25:47PM -0400, Steven Rostedt wrote: > On Wed, 24 May 2017 21:13:27 +0200 (CEST) > Thomas Gleixner wrote: > > > > > Oops: 0003 [#1] SMP > > > Modules linked in: > > > CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc2-test+ #42 > > > Hardware

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, May 24, 2017 at 06:25:47PM -0400, Steven Rostedt wrote: > On Wed, 24 May 2017 21:13:27 +0200 (CEST) > Thomas Gleixner wrote: > > > > > Oops: 0003 [#1] SMP > > > Modules linked in: > > > CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc2-test+ #42 > > > Hardware name: MSI

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, 24 May 2017 21:13:27 +0200 (CEST) Thomas Gleixner wrote: > > Oops: 0003 [#1] SMP > > Modules linked in: > > CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc2-test+ #42 > > Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 > > 02/22/2014 task:

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, 24 May 2017 21:13:27 +0200 (CEST) Thomas Gleixner wrote: > > Oops: 0003 [#1] SMP > > Modules linked in: > > CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc2-test+ #42 > > Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 > > 02/22/2014 task: 8802153a8000 task.stack:

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, May 24, 2017 at 08:53:00PM +0200, Thomas Gleixner wrote: > On Wed, 24 May 2017, Luis R. Rodriguez wrote: > > [ 440.548057] CPU: 2 PID: 1765 Comm: ftracetest Tainted: GE > > 4.12.0-rc1-next-20170519+ #155 > > Can you please try that patch against plain 4.12-rc2? Yup, just

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, May 24, 2017 at 08:53:00PM +0200, Thomas Gleixner wrote: > On Wed, 24 May 2017, Luis R. Rodriguez wrote: > > [ 440.548057] CPU: 2 PID: 1765 Comm: ftracetest Tainted: GE > > 4.12.0-rc1-next-20170519+ #155 > > Can you please try that patch against plain 4.12-rc2? Yup, just

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, 24 May 2017, Steven Rostedt wrote: > OK, it crashed on one of my tests. I removed the patch and it boots > fine, and crashes when I add it back. It reproduces here with your config. > BUG: unable to handle kernel paging request at 880214f5c000 > IP: new_slab+0x1e8/0x2b4 > PGD

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, 24 May 2017, Steven Rostedt wrote: > OK, it crashed on one of my tests. I removed the patch and it boots > fine, and crashes when I add it back. It reproduces here with your config. > BUG: unable to handle kernel paging request at 880214f5c000 > IP: new_slab+0x1e8/0x2b4 > PGD

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, 24 May 2017, Luis R. Rodriguez wrote: > [ 440.548057] CPU: 2 PID: 1765 Comm: ftracetest Tainted: GE 4.12.0-rc1-next-20170519+ #155 Can you please try that patch against plain 4.12-rc2? Thanks, tglx

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, 24 May 2017, Luis R. Rodriguez wrote: > [ 440.548057] CPU: 2 PID: 1765 Comm: ftracetest Tainted: GE 4.12.0-rc1-next-20170519+ #155 Can you please try that patch against plain 4.12-rc2? Thanks, tglx

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, May 24, 2017 at 01:47:28PM -0400, Steven Rostedt wrote: > OK, it crashed on one of my tests. I removed the patch and it boots > fine, and crashes when I add it back. > > Here's the crash: > > Running tests on all trace events: > Testing all events: OK > Testing ftrace filter: OK >

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, May 24, 2017 at 01:47:28PM -0400, Steven Rostedt wrote: > OK, it crashed on one of my tests. I removed the patch and it boots > fine, and crashes when I add it back. > > Here's the crash: > > Running tests on all trace events: > Testing all events: OK > Testing ftrace filter: OK >

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

OK, it crashed on one of my tests. I removed the patch and it boots fine, and crashes when I add it back. Here's the crash: Running tests on all trace events: Testing all events: OK Testing ftrace filter: OK trace_kprobe: Testing kprobe tracing: BUG: unable to handle kernel paging request at

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

OK, it crashed on one of my tests. I removed the patch and it boots fine, and crashes when I add it back. Here's the crash: Running tests on all trace events: Testing all events: OK Testing ftrace filter: OK trace_kprobe: Testing kprobe tracing: BUG: unable to handle kernel paging request at

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, 24 May 2017 15:47:17 +0200 (CEST) Thomas Gleixner wrote: > ftrace uses module_alloc() to allocate trampoline pages. The mapping > of module_alloc() is RWX, which makes sense as the memory is written > to right after allocation. But nothing makes these pages RO after >

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, 24 May 2017 15:47:17 +0200 (CEST) Thomas Gleixner wrote: > ftrace uses module_alloc() to allocate trampoline pages. The mapping > of module_alloc() is RWX, which makes sense as the memory is written > to right after allocation. But nothing makes these pages RO after > writing to them. >

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, 24 May 2017 15:47:17 +0200 (CEST) Thomas Gleixner wrote: > ftrace uses module_alloc() to allocate trampoline pages. The mapping of > module_alloc() is RWX, which makes sense as the memory is written to right > after allocation. But nothing makes these pages RO after

Re: [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

On Wed, 24 May 2017 15:47:17 +0200 (CEST) Thomas Gleixner wrote: > ftrace uses module_alloc() to allocate trampoline pages. The mapping of > module_alloc() is RWX, which makes sense as the memory is written to right > after allocation. But nothing makes these pages RO after writing to them. > >

[PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

ftrace uses module_alloc() to allocate trampoline pages. The mapping of module_alloc() is RWX, which makes sense as the memory is written to right after allocation. But nothing makes these pages RO after writing to them. This problem exists since ftrace uses trampolines on x86, but it went

[PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX

ftrace uses module_alloc() to allocate trampoline pages. The mapping of module_alloc() is RWX, which makes sense as the memory is written to right after allocation. But nothing makes these pages RO after writing to them. This problem exists since ftrace uses trampolines on x86, but it went