Re: [PATCH net 4/4] lib/test_bpf: Add additional BPF_ADD tests

org> Signed-off-by: Naveen N. Rao <naveen.n@linux.vnet.ibm.com> Makes sense. Looks like ppc jit will be using quite a bit of available ppc instructions. Nice. I'm assuming all these new tests passed with x64 jit? Acked-by: Alexei Starovoitov <a...@kernel.org>

Re: [PATCH 3/5] perf core: Prepare writing into ring buffer from end

On Wed, Mar 23, 2016 at 06:08:41PM +0800, Wangnan (F) wrote: > > > On 2016/3/23 17:50, Peter Zijlstra wrote: > >On Mon, Mar 14, 2016 at 09:59:43AM +, Wang Nan wrote: > >>Convert perf_output_begin to __perf_output_begin and make the later > >>function able to write records from the end of the

Re: [PATCH 3/5] perf core: Prepare writing into ring buffer from end

On Thu, Mar 24, 2016 at 11:48:54AM +0800, Wangnan (F) wrote: > > >>http://lkml.iu.edu/hypermail/linux/kernel/1601.2/03966.html > >Wang, when you respin, please add all perf analysis that you've > >done and the reasons to do it this way to commit log > >to make sure it stays in git history. > > >

[PATCH v2 net-next 01/12] bpf: prevent kprobe+bpf deadlocks

helpers don't have this problem, since they don't hold any locks and don't modify global data. bpf_trace_printk has its own recursive check and ok as well. Signed-off-by: Alexei Starovoitov <a...@kernel.org> Acked-by: Daniel Borkmann <dan...@iogearbox.net> --- include/linux/bpf

[PATCH v2 net-next 05/12] bpf: convert stackmap to pre-allocation

and kernel side updates is also present in hashmap, but it's not a new race. bpf programs were always allowed to modify hash and array map elements while user space is copying them. Fixes: d5a3b1f69186 ("bpf: introduce BPF_MAP_TYPE_STACK_TRACE") Signed-off-by: Alexei Starovoitov <a.

[PATCH v2 net-next 04/12] bpf: check for reserved flag bits in array and stack maps

Suggested-by: Daniel Borkmann <dan...@iogearbox.net> Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- kernel/bpf/arraymap.c | 2 +- kernel/bpf/stackmap.c | 3 +++ 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index

[PATCH v2 net-next 09/12] samples/bpf: test both pre-alloc and normal maps

extend test coveraged to include pre-allocated and run-time alloc maps Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- samples/bpf/test_maps.c | 10 +- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/samples/bpf/test_maps.c b/samples/bpf/test_maps.c

[PATCH v2 net-next 08/12] samples/bpf: add map_flags to bpf loader

note old loader is compatible with new kernel. map_flags are optional Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- samples/bpf/bpf_helpers.h | 1 + samples/bpf/bpf_load.c | 3 ++- samples/bpf/fds_example.c | 2 +- samples/bpf/libbpf.c| 5 +++-- sampl

[PATCH v2 net-next 0/12] bpf: map pre-alloc

sh map infra. It attaches to spin_lock functions and bpf_map_update/delete are called from different contexts Patch 11: stress for bpf_get_stackid Patch 12: map performance test Reported-by: Daniel Wagner <daniel.wag...@bmw-carit.de> Reported-by: Tom Zanussi <tom.zanu...@linux.intel.com>

[PATCH v2 net-next 02/12] bpf: introduce percpu_freelist

on the same cpu. Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- kernel/bpf/Makefile | 2 +- kernel/bpf/percpu_freelist.c | 100 +++ kernel/bpf/percpu_freelist.h | 31 ++ 3 files changed, 132 insertions(+), 1 deletion(-) creat

[PATCH v2 net-next 07/12] samples/bpf: move ksym_search() into library

move ksym search from offwaketime into library to be reused in other tests Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- samples/bpf/bpf_load.c | 62 ++ samples/bpf/bpf_load.h | 6 samples/bpf/offwaketime_user.

[PATCH v2 net-next 06/12] samples/bpf: make map creation more verbose

map creation is typically the first one to fail when rlimits are too low, not enough memory, etc Make this failure scenario more verbose Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- samples/bpf/bpf_load.c | 5 - 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/s

[PATCH v2 net-next 03/12] bpf: pre-allocate hash map elements

cond is low, it may make sense to use it. Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- include/linux/bpf.h | 2 + include/uapi/linux/bpf.h | 3 + kernel/bpf/hashtab.c | 240 +-- kernel/bpf/syscall.c | 15 ++- 4 files chan

Re: [PATCH v2 net-next 0/12] bpf: map pre-alloc

On 3/8/16 1:13 AM, Daniel Wagner wrote: Some time back Daniel Wagner reported crashes when bpf hash map is >used to compute time intervals between preempt_disable->preempt_enable >and recently Tom Zanussi reported a dead lock in iovisor/bcc/funccount >tool if it's used to count the number of

[PATCH net-next 8/9] samples/bpf: add bpf map stress test

by walking and deleting map elements. Note that due to nature bpf_load.c the earlier kprobe+bpf programs are already active while loader loads new programs, creates new kprobes and attaches them. Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- samples/bpf/Makefile| 4 +++ sampl

[PATCH net-next 2/9] bpf: introduce percpu_freelist

on the same cpu. Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- kernel/bpf/Makefile | 2 +- kernel/bpf/percpu_freelist.c | 81 kernel/bpf/percpu_freelist.h | 31 + 3 files changed, 113 insertions(+), 1 deletion(-) creat

[PATCH net-next 4/9] samples/bpf: make map creation more verbose

map creation is typically the first one to fail when rlimits are too low, not enough memory, etc Make this failure scenario more verbose Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- samples/bpf/bpf_load.c | 5 - 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/s

[PATCH net-next 7/9] samples/bpf: test both pre-alloc and normal maps

extend test coveraged to include pre-allocated and run-time alloc maps Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- samples/bpf/test_maps.c | 10 +- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/samples/bpf/test_maps.c b/samples/bpf/test_maps.c

[PATCH net-next 6/9] samples/bpf: add map_flags to bpf loader

note old loader is compatible with new kernel. map_flags are optional Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- samples/bpf/bpf_helpers.h | 1 + samples/bpf/bpf_load.c | 3 ++- samples/bpf/fds_example.c | 2 +- samples/bpf/libbpf.c| 5 +++-- sampl

[PATCH net-next 3/9] bpf: pre-allocate hash map elements

low, it may make sense to use it. Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 3 + kernel/bpf/hashtab.c | 264 ++- kernel/bpf/syscall.c | 2 +- 4 files changed, 196

[PATCH net-next 5/9] samples/bpf: move ksym_search() into library

move ksym search from offwaketime into library to be reused in other tests Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- samples/bpf/bpf_load.c | 62 ++ samples/bpf/bpf_load.h | 6 samples/bpf/offwaketime_user.

[PATCH net-next 1/9] bpf: prevent kprobe+bpf deadlocks

helpers don't have this problem, since they don't hold any locks and don't modify global data. bpf_trace_printk has its own recursive check and ok as well. Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- include/linux/bpf.h | 3 +++ kernel/bpf/syscall.c | 13 +

[PATCH net-next 0/9] bpf: hash map pre-alloc

Reported-by: Tom Zanussi <tom.zanu...@linux.intel.com> Alexei Starovoitov (9): bpf: prevent kprobe+bpf deadlocks bpf: introduce percpu_freelist bpf: pre-allocate hash map elements samples/bpf: make map creation more verbose samples/bpf: move ksym_search() into library samples/bpf

[PATCH net-next 9/9] samples/bpf: add map performance test

performance tests for hash map and per-cpu hash map with and without pre-allocation Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- samples/bpf/Makefile | 4 + samples/bpf/map_perf_test_kern.c | 100 + samples/bpf/map_perf_test_user.c

Re: [PATCH net-next 2/9] bpf: introduce percpu_freelist

On 3/7/16 2:33 AM, Daniel Borkmann wrote: On 03/07/2016 02:58 AM, Alexei Starovoitov wrote: Introduce simple percpu_freelist to keep single list of elements spread across per-cpu singly linked lists. /* push element into the list */ void pcpu_freelist_push(struct pcpu_freelist *, struct

Re: [PATCH net-next 3/9] bpf: pre-allocate hash map elements

On 3/7/16 3:08 AM, Daniel Borkmann wrote: On 03/07/2016 02:58 AM, Alexei Starovoitov wrote: [...] --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 3 + kernel/bpf/hashtab.c | 264 ++- kernel/bpf/syscall.c | 2 +- 4

slab-out-of-bounds in rpc/nfs

seeing on ton of these errors on net-next with kasan on. Likely old bug though. [ 373.705691] BUG: KASAN: slab-out-of-bounds in memcpy+0x28/0x40 at addr 8811ada62cb0 [ 373.707137] Write of size 28 by task bash/7059 [ 373.708177]

Re: [PATCH 2/4] samples/bpf: Use llc in PATH, rather than a hardcoded value

On 4/1/16 7:37 AM, Naveen N. Rao wrote: On 2016/03/31 08:19PM, Daniel Borkmann wrote: On 03/31/2016 07:46 PM, Alexei Starovoitov wrote: On 3/31/16 4:25 AM, Naveen N. Rao wrote: clang $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) \ -D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused

Re: [PATCH 4/4] samples/bpf: Enable powerpc support

On 4/1/16 7:41 AM, Naveen N. Rao wrote: On 2016/03/31 10:52AM, Alexei Starovoitov wrote: On 3/31/16 4:25 AM, Naveen N. Rao wrote: ... + +#ifdef __powerpc__ +#define BPF_KPROBE_READ_RET_IP(ip, ctx){ (ip) = (ctx)->link; } +#define BPF_KRETPROBE_READ_RET_IP(ip,

Re: [RFC PATCH 6/6] ppc: ebpf/jit: Implement JIT compiler for extended BPF

F tail calls and skb loads. Cc: Matt Evans <m...@ozlabs.org> Cc: Michael Ellerman <m...@ellerman.id.au> Cc: Paul Mackerras <pau...@samba.org> Cc: Alexei Starovoitov <a...@fb.com> Cc: "David S. Miller" <da...@davemloft.net> Cc: Ananth N Mavinakayanahalli &l

[PATCH net-next 8/8] samples/bpf: add tracepoint vs kprobe performance tests

); } and on 4 cpus in parallel: reads per sec base (no tracepoints, no kprobes) 300k with kprobe at urandom_read() 279k with tracepoint at random:urandom_read290k bpf progs attached to kprobe and tracepoint are noop. Signed-off-by: Alexei Starovoitov

[PATCH net-next 2/8] perf, bpf: allow bpf programs attach to tracepoints

and some application access it directly without consulting tracepoint/format. Same rule applies here: static tracepoint fields should only be accessed in a format defined in tracepoint/format. The order of fields and field sizes are not an ABI. Signed-off-by: Alexei Starovoitov <a...@kernel.

[PATCH net-next 4/8] bpf: support bpf_get_stackid() and bpf_perf_event_output() in tracepoint programs

needs two wrapper functions to fetch 'struct pt_regs *' to convert tracepoint bpf context into kprobe bpf context to reuse existing helper functions Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- include/linux/bpf.h | 1 + kernel/bpf/stackmap.c| 2 +- kernel/trace/bpf_t

[PATCH net-next 3/8] bpf: register BPF_PROG_TYPE_TRACEPOINT program type

register tracepoint bpf program type and let it call the same set of helper functions as BPF_PROG_TYPE_KPROBE Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- kernel/trace/bpf_trace.c | 45 +++-- 1 file changed, 43 insertions(+), 2 del

[PATCH net-next 7/8] samples/bpf: tracepoint example

modify offwaketime to work with sched/sched_switch tracepoint instead of kprobe into finish_task_switch Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- samples/bpf/offwaketime_kern.c | 26 ++ 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/s

[PATCH net-next 6/8] samples/bpf: add tracepoint support to bpf loader

Recognize "tracepoint/" section name prefix and attach the program to that tracepoint. Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- samples/bpf/bpf_load.c | 26 +- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/samples/bpf/bpf_

[PATCH net-next 1/8] perf: optimize perf_fetch_caller_regs

call to perf_arch_fetch_caller_regs initializes the same fields on all archs, so we can safely drop memset from all of the above cases and move it into perf_ftrace_function_call that calls it with stack allocated pt_regs. Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- include/linux/perf_event.

[PATCH net-next 0/8] allow bpf attach to tracepoints

thread.gmane.org/gmane.linux.kernel.api/8127/focus=8165 [2] https://github.com/iovisor/bcc/blob/master/tools/tplist.py [3] https://github.com/iovisor/bcc/blob/master/tools/argdist.py Alexei Starovoitov (8): perf: optimize perf_fetch_caller_regs perf, bpf: allow bpf programs attach to tracepoints

[PATCH net-next 5/8] bpf: sanitize bpf tracepoint access

-off-by: Alexei Starovoitov <a...@kernel.org> --- include/linux/bpf.h | 1 + include/linux/trace_events.h | 1 + kernel/bpf/verifier.c| 6 +- kernel/events/core.c | 8 kernel/trace/trace_events.c | 18 ++ 5 files changed, 33 insertions

Re: [PATCH 1/4 fix] perf core: Introduce new ioctl options to pause and resume ring buffer

or > the reading is unreliable. > > Signed-off-by: Wang Nan <wangn...@huawei.com> > Cc: He Kuang <heku...@huawei.com> > Cc: Alexei Starovoitov <a...@kernel.org> > Cc: Arnaldo Carvalho de Melo <a...@redhat.com> > Cc: Brendan Gregg <brendan.d.gr...@gmail.co

Re: [PATCH 4/4] perf core: Add backward attribute to perf event

On Tue, Mar 29, 2016 at 10:01:24AM +0800, Wangnan (F) wrote: > > > On 2016/3/28 14:41, Wang Nan wrote: > > [SNIP] > > > > >To prevent this problem, we need to find a way to ensure the ring buffer > >is stable during reading. ioctl(PERF_EVENT_IOC_PAUSE_OUTPUT) is > >suggested because its

Re: [PATCH 4/4] samples/bpf: Enable powerpc support

this to work with x86_64 and arm64, but not s390. Cc: Alexei Starovoitov <a...@fb.com> Cc: David S. Miller <da...@davemloft.net> Cc: Ananth N Mavinakayanahalli <ana...@in.ibm.com> Cc: Michael Ellerman <m...@ellerman.id.au> Signed-off-by: Naveen N. Rao <nave

Re: [PATCH 1/4] samples/bpf: Fix build breakage with map_perf_test_user.c

}; ^ Fix this by including the necessary header file. Cc: Alexei Starovoitov <a...@fb.com> Cc: David S. Miller <da...@davemloft.net> Cc: Ananth N Mavinakayanahalli <ana...@in.ibm.com> Cc: Michael Ellerman <m...@ellerman.id.au> Signed-off-by: Naveen N. Rao <nave

Re: [PATCH 2/4] samples/bpf: Use llc in PATH, rather than a hardcoded value

On 3/31/16 4:25 AM, Naveen N. Rao wrote: While at it, fix some typos in the comment. Cc: Alexei Starovoitov <a...@fb.com> Cc: David S. Miller <da...@davemloft.net> Cc: Ananth N Mavinakayanahalli <ana...@in.ibm.com> Cc: Michael Ellerman <m...@ellerman.id.au> Sign

Re: [PATCH 3/4] samples/bpf: Simplify building BPF samples

On 3/31/16 11:51 AM, Naveen N. Rao wrote: On 2016/03/31 10:49AM, Alexei Starovoitov wrote: On 3/31/16 4:25 AM, Naveen N. Rao wrote: Make BPF samples build depend on CONFIG_SAMPLE_BPF. We still don't add a Kconfig option since that will add a dependency on llvm for allyesconfig builds which may

Re: [PATCH 3/4] samples/bpf: Simplify building BPF samples

On 3/31/16 4:25 AM, Naveen N. Rao wrote: Make BPF samples build depend on CONFIG_SAMPLE_BPF. We still don't add a Kconfig option since that will add a dependency on llvm for allyesconfig builds which may not be desirable. Those who need to build the BPF samples can now just do: make

Re: [PATCH 1/4] samples/bpf: Fix build breakage with map_perf_test_user.c

On 3/31/16 11:46 AM, Naveen N. Rao wrote: It's failing this way on powerpc? Odd. This fails for me on x86_64 too -- RHEL 7.1. indeed. fails on centos 7.1, whereas centos 6.7 is fine.

Re: [PATCHv2 net 2/3] samples/bpf: Use llc in PATH, rather than a hardcoded value

On Mon, Apr 04, 2016 at 10:31:33PM +0530, Naveen N. Rao wrote: > While at it, remove the generation of .s files and fix some typos in the > related comment. > > Cc: Alexei Starovoitov <a...@fb.com> > Cc: David S. Miller <da...@davemloft.net> > Cc: Daniel Borkma

Re: [PATCHv2 net 3/3] samples/bpf: Enable powerpc support

EGS_IP() to access the instruction pointer. > > Cc: Alexei Starovoitov <a...@fb.com> > Cc: Daniel Borkmann <dan...@iogearbox.net> > Cc: David S. Miller <da...@davemloft.net> > Cc: Ananth N Mavinakayanahalli <ana...@in.ibm.com> > Cc: Michael Ellerman &l

Re: [PATCH/RFC v2] perf core: Allow setting up max frame stack depth via sysctl

On Fri, Apr 22, 2016 at 05:52:32PM -0300, Arnaldo Carvalho de Melo wrote: > Em Wed, Apr 20, 2016 at 04:04:12PM -0700, Alexei Starovoitov escreveu: > > On Wed, Apr 20, 2016 at 07:47:30PM -0300, Arnaldo Carvalho de Melo wrote: > > > Nice. I like it. That's a great approa

Re: [PATCH/RFC v2] perf core: Allow setting up max frame stack depth via sysctl

On Mon, Apr 25, 2016 at 04:22:29PM -0300, Arnaldo Carvalho de Melo wrote: > Em Mon, Apr 25, 2016 at 01:27:06PM -0300, Arnaldo Carvalho de Melo escreveu: > > Em Mon, Apr 25, 2016 at 01:14:25PM -0300, Arnaldo Carvalho de Melo escreveu: > > > Em Fri, Apr 22, 2016 at 03:18:

Re: [PATCH/RFC v2] perf core: Allow setting up max frame stack depth via sysctl

On Mon, Apr 25, 2016 at 05:17:50PM -0300, Arnaldo Carvalho de Melo wrote: > Em Mon, Apr 25, 2016 at 01:06:48PM -0700, Alexei Starovoitov escreveu: > > On Mon, Apr 25, 2016 at 04:22:29PM -0300, Arnaldo Carvalho de Melo wrote: > > > Em Mon, Apr 25, 2016 at 01:27:06PM -0300, Arnald

Re: [PATCH/RFC v2] perf core: Allow setting up max frame stack depth via sysctl

On Mon, Apr 25, 2016 at 08:41:39PM -0300, Arnaldo Carvalho de Melo wrote: > > +int sysctl_perf_event_max_stack __read_mostly = PERF_MAX_STACK_DEPTH; > + > +static inline size_t perf_callchain_entry__sizeof(void) > +{ > + return (sizeof(struct perf_callchain_entry) + > +

Re: [PATCH/RFC v3] perf core: Allow setting up max frame stack depth via sysctl

On Mon, Apr 25, 2016 at 09:29:28PM -0300, Arnaldo Carvalho de Melo wrote: > Em Mon, Apr 25, 2016 at 05:07:26PM -0700, Alexei Starovoitov escreveu: > > > + { > > > + .procname = "perf_event_max_stack", > > > + .data

Re: [PATCH 0/2] bfp tools: Couple Coverity fixes

On Wed, Apr 27, 2016 at 11:00:23AM +0800, Wangnan (F) wrote: > > > On 2016/4/27 10:46, Florian Fainelli wrote: > >Le 24/04/2016 19:34, Florian Fainelli a écrit : > >>Hi all, > >> > >>Two trivial patches that were flagged by Coverity. > >> > >>Thanks! > >Ping! Did I send this to the correct

Re: LBR callchains from tracepoints

On Tue, Apr 26, 2016 at 06:38:28PM +0200, Peter Zijlstra wrote: > On Mon, Apr 25, 2016 at 10:24:31PM -0300, Arnaldo Carvalho de Melo wrote: > > Em Mon, Apr 25, 2016 at 10:03:58PM -0300, Arnaldo Carvalho de Melo escreveu: > > > I now need to continue investigation why this doesn't seem to work from

Re: [PATCH/RFC v2] perf core: Allow setting up max frame stack depth via sysctl

On Fri, Apr 22, 2016 at 04:05:31PM -0600, David Ahern wrote: > On 4/22/16 2:52 PM, Arnaldo Carvalho de Melo wrote: > >Em Wed, Apr 20, 2016 at 04:04:12PM -0700, Alexei Starovoitov escreveu: > >>On Wed, Apr 20, 2016 at 07:47:30PM -0300, Arnaldo Carvalho de Melo wrote: > > >

Re: bpf: use-after-free in array_map_alloc

er seen. Tested-by: Alexei Starovoitov <a...@kernel.org> > > Thanks. > > diff --git a/mm/percpu.c b/mm/percpu.c > index 0c59684..bd2df70 100644 > --- a/mm/percpu.c > +++ b/mm/percpu.c > @@ -162,7 +162,7 @@ static struct pcpu_chunk *pcpu_reserved_chunk; > sta

Re: [for-next][PATCH 2/2] tracing: Use temp buffer when filtering events

nterrupted event. Perf does the same thing, but all the time. yeah. good point. there is no actual 'order' here. The whole thing looks good to me. Acked-by: Alexei Starovoitov <a...@kernel.org>

Re: [for-next][PATCH 2/2] tracing: Use temp buffer when filtering events

slower, but > that may be well within the noise. > > The third run shows that discarding all events only took 1.3 seconds. This > is a speed up of 23%! The discard is much faster than even the commit. > > The one downside is shown in the last run. Events that are not discarded by >

Re: [PATCH] bpf: avoid warning for wrong pointer cast

On 4/19/16 3:09 AM, Philip Li wrote: On Tue, Apr 19, 2016 at 10:33:34AM +0800, Fengguang Wu wrote: Fengguang, any idea why build-bot sometimes silent? Sorry I went off for some time.. Philip, would you help have a check? Hi Alexei, i have done some investigation for this. Fengguang, pls

Re: [PATCH net-next 2/8] perf, bpf: allow bpf programs attach to tracepoints

On 4/18/16 3:16 PM, Steven Rostedt wrote: On Mon, 18 Apr 2016 14:43:07 -0700 Alexei Starovoitov <a...@fb.com> wrote: I was worried about this too, but single 'if' and two calls (as in commit 98b5c2c65c295) is a better way, since it's faster, cleaner and doesn't need to refactor the

Re: [PATCH] bpf: avoid warning for wrong pointer cast

ize as a pointer. > > Signed-off-by: Arnd Bergmann <a...@arndb.de> > Fixes: 9940d67c93b5 ("bpf: support bpf_get_stackid() and > bpf_perf_event_output() in tracepoint programs") Thanks. Acked-by: Alexei Starovoitov <a...@kernel.org> I guess I started to rely on 0-

Re: bpf: use-after-free in array_map_alloc

On Sun, Apr 17, 2016 at 12:58:21PM -0400, Sasha Levin wrote: > Hi all, > > I've hit the following while fuzzing with syzkaller inside a KVM tools guest > running the latest -next kernel: thanks for the report. Adding Tejun... if I read the report correctly it's not about bpf, but rather points

Re: [PATCH/RFC] perf core: Allow setting up max frame stack depth via sysctl

On Wed, Apr 20, 2016 at 07:47:30PM -0300, Arnaldo Carvalho de Melo wrote: > The default remains 127, which is good for most cases, and not even hit > most of the time, but then for some cases, as reported by Brendan, 1024+ > deep frames are appearing on the radar for things like groovy, ruby. >

Re: [PATCH net-next 0/8] allow bpf attach to tracepoints

On 4/18/16 9:13 AM, Steven Rostedt wrote: On Mon, 4 Apr 2016 21:52:46 -0700 Alexei Starovoitov <a...@fb.com> wrote: Hi Steven, Peter, last time we discussed bpf+tracepoints it was a year ago [1] and the reason we didn't proceed with that approach was that bpf would make arguments arg1

[PATCH net-next] perf, bpf: minimize the size of perf_trace_() tracepoint handler

perf tracepoints. Suggested-by: Steven Rostedt <rost...@goodmis.org> Signed-off-by: Alexei Starovoitov <a...@kernel.org> --- include/linux/trace_events.h | 5 + include/trace/perf.h | 13 +++-- kernel/events/core.c | 20 +++- 3 files

Re: [PATCH net-next 2/8] perf, bpf: allow bpf programs attach to tracepoints

On 4/18/16 1:29 PM, Steven Rostedt wrote: On Mon, 4 Apr 2016 21:52:48 -0700 Alexei Starovoitov <a...@fb.com> wrote: introduce BPF_PROG_TYPE_TRACEPOINT program type and allow it to be attached to tracepoints. The tracepoint will copy the arguments in the per-cpu buffer and pass it to t

Re: [PATCH net-next 0/8] allow bpf attach to tracepoints

On 4/18/16 1:47 PM, Steven Rostedt wrote: On Mon, 18 Apr 2016 12:51:43 -0700 Alexei Starovoitov <a...@fb.com> wrote: yeah, it could be added to ftrace as well, but it won't be as effective as perf_trace, since the cost of trace_event_buffer_reserve() in trace_event_raw_event_() h

Re: [RFC PATCH 00/13] perf tools: Support uBPF script

On Wed, Apr 20, 2016 at 06:01:40PM +, Wang Nan wrote: > This patch set allows to perf invoke some user space BPF scripts on some > point. uBPF scripts and kernel BPF scripts reside in one BPF object. > They communicate with each other with BPF maps. uBPF scripts can invoke > helper functions

Re: bpf: use-after-free in array_map_alloc

On Tue, May 24, 2016 at 12:04 PM, Tejun Heo wrote: > Hello, > > Alexei, can you please verify this patch? Map extension got rolled > into balance work so that there's no sync issues between the two async > operations. tests look good. No uaf and basic bpf tests exercise per-cpu

Re: [PATCH 1/1] tracing, bpf: Implement function bpf_probe_write

On Wed, Jul 13, 2016 at 03:36:11AM -0700, Sargun Dhillon wrote: > Provides BPF programs, attached to kprobes a safe way to write to > memory referenced by probes. This is done by making probe_kernel_write > accessible to bpf functions via the bpf_probe_write helper. not quite :) > Signed-off-by:

Re: [PATCH v4 1/2] bpf: Add bpf_probe_write BPF helper to be called in tracers (kprobes)

On Fri, Jul 22, 2016 at 11:53:52AM +0200, Daniel Borkmann wrote: > On 07/22/2016 04:14 AM, Alexei Starovoitov wrote: > >On Thu, Jul 21, 2016 at 06:09:17PM -0700, Sargun Dhillon wrote: > >>This allows user memory to be written to during the course of a kprobe. > >>It sho

Re: Relax kern_version constraints on bpf kprobes?

On Sat, Jul 23, 2016 at 09:01:39PM -0700, Sargun Dhillon wrote: > In kernel/bpf/syscall.c we restrict programs loading bpf kprobe programs so > attr.kern_version must be exactly equal to what the user is running at the > moment. This makes a lot of sense because kprobes can touch lots of >

Re: [PATCH net-next v5 1/2] bpf: Add bpf_probe_write_user BPF helper to be called in tracers

+ current->comm, task_pid_nr(current)); I think checkpatch should have complained here. current->comm line should start under " No other nits for this patch :) Once fixed, feel free to add my Acked-by: Alexei Starovoitov <a...@kernel.org>

Re: [PATCH net-next v6 0/2] bpf: add bpf_probe_write_user helper & example

at > uses it, in one the intended ways to divert execution. > > Thanks to Alexei Starovoitov, and Daniel Borkmann for review, I've made > changes based on their recommendations. > > This helper should be considered experimental, so we print a warning > to dmesg when it is

Re: [PATCH net-next v5 2/2] samples/bpf: Add test/example of using bpf_probe_write_user bpf helper

On Sat, Jul 23, 2016 at 05:44:11PM -0700, Sargun Dhillon wrote: > This example shows using a kprobe to act as a dnat mechanism to divert > traffic for arbitrary endpoints. It rewrite the arguments to a syscall > while they're still in userspace, and before the syscall has a chance > to copy the

Re: [PATCH v4 1/2] bpf: Add bpf_probe_write BPF helper to be called in tracers (kprobes)

On Sat, Jul 23, 2016 at 05:39:42PM -0700, Sargun Dhillon wrote: > The example has been modified to act like a test in the follow up set. It > tests > for the positive case (Did the helper work or not) as opposed to the negative > case (is the helper able to violate the safety constraints we set

Re: [PATCH v4 1/2] bpf: Add bpf_probe_write BPF helper to be called in tracers (kprobes)

t; the system, we print a warning on invocation. > > It was tested with the tracex7 program on x86-64. > > Signed-off-by: Sargun Dhillon <sar...@sargun.me> > Cc: Alexei Starovoitov <a...@kernel.org> > Cc: Daniel Borkmann <dan...@iogearbox.net> > --- > in

Re: [PATCH] samples/bpf: fix resource leak on opened file descriptor

On Sun, Jul 24, 2016 at 06:50:47PM +0100, Colin King wrote: > From: Colin Ian King <colin.k...@canonical.com> > > file f needs to be closed, fixes resource leak. > > Signed-off-by: Colin Ian King <colin.k...@canonical.com> have been travelling. sorry for delay. A

Re: [PATCH v2] bpf: silence warnings when building kernel/bpf/core.c with W=1

On Mon, Aug 01, 2016 at 12:33:30AM -0400, Valdis Kletnieks wrote: > Building with W=1 generates some 350 lines of warnings of the form: > > kernel/bpf/core.c: In function '__bpf_prog_run': > kernel/bpf/core.c:476:33: warning: initialized field overwritten > [-Woverride-init] >[BPF_ALU |

Re: [PATCH v2] bpf: silence warnings when building kernel/bpf/core.c with W=1

On Mon, Aug 01, 2016 at 01:18:43AM -0400, valdis.kletni...@vt.edu wrote: > On Sun, 31 Jul 2016 21:42:22 -0700, Alexei Starovoitov said: > > > and at least 2 other such patches for other files... > > Is there a single warning where -Woverride-init was useful? > >

Re: perf test BPF failing on f24: fix

On Tue, Aug 02, 2016 at 04:51:02PM -0300, Arnaldo Carvalho de Melo wrote: > Hi Wang, > > Something changed and a function used in a perf test for BPF is > not anymore appearing on vmlinux, albeit still available on > /proc/kallsyms: > > # readelf -wi /lib/modules/4.7.0+/build/vmlinux |

Re: perf test BPF failing on f24: fix

On Tue, Aug 02, 2016 at 11:15:34PM -0300, Arnaldo Carvalho de Melo wrote: > Em Tue, Aug 02, 2016 at 02:03:33PM -0700, Alexei Starovoitov escreveu: > > On Tue, Aug 02, 2016 at 04:51:02PM -0300, Arnaldo Carvalho de Melo wrote: > > > Hi Wang, > > > > > > S

Re: [PATCH] tools lib bpf: Use official ELF e_machine value

T_REL) || (ep->e_machine != 0)) { > + /* Old LLVM set e_machine to EM_NONE */ > + if ((ep->e_type != ET_REL) || (ep->e_machine && (ep->e_machine != > EM_BPF))) { Thanks for the fix. Didn't realize we already check for zero here. btw EM_BPF will be in llvm 3.9 release. Acked-by: Alexei Starovoitov <a...@kernel.org>

Re: [PATCH 1/1] tracing, bpf: Implement function bpf_probe_write

On Sun, Jul 17, 2016 at 03:19:13AM -0700, Sargun Dhillon wrote: > > +static u64 bpf_copy_to_user(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) > +{ > + void *to = (void *) (long) r1; > + void *from = (void *) (long) r2; > + int size = (int) r3; > + > + /* check if we're in a user

Re: [PATCH 1/1] tracing, bpf: Implement function bpf_probe_write

On Mon, Jul 18, 2016 at 03:57:17AM -0700, Sargun Dhillon wrote: > > > On Sun, 17 Jul 2016, Alexei Starovoitov wrote: > > >On Sun, Jul 17, 2016 at 03:19:13AM -0700, Sargun Dhillon wrote: > >> > >>+static u64 bpf_copy_to_user(u64 r1, u64 r2, u64 r3, u64 r4, u64

Re: [PATCH net-next v3 1/2] bpf: Add bpf_copy_to_user BPF helper to be called in tracers (kprobes)

On Tue, Jul 19, 2016 at 01:17:53PM +0200, Daniel Borkmann wrote: > >+return -EINVAL; > >+ > >+/* Is this a user address, or a kernel address? */ > >+if (!access_ok(VERIFY_WRITE, to, size)) > >+return -EINVAL; > >+ > >+return probe_kernel_write(to, from, size); >

Re: [PATCH net-next v3 1/2] bpf: Add bpf_copy_to_user BPF helper to be called in tracers (kprobes)

On Wed, Jul 20, 2016 at 01:19:51AM +0200, Daniel Borkmann wrote: > On 07/19/2016 06:34 PM, Alexei Starovoitov wrote: > >On Tue, Jul 19, 2016 at 01:17:53PM +0200, Daniel Borkmann wrote: > >>>+ return -EINVAL; > >>>+ > >>>+ /

Re: [PATCH 1/1] tracing, bpf: Implement function bpf_probe_write

On Wed, Jul 13, 2016 at 01:31:57PM -0700, Sargun Dhillon wrote: > > > On Wed, 13 Jul 2016, Alexei Starovoitov wrote: > > > On Wed, Jul 13, 2016 at 03:36:11AM -0700, Sargun Dhillon wrote: > >> Provides BPF programs, attached to kprobes a safe way to write to >

Re: [PATCH 1/1] tracing, bpf: Implement function bpf_probe_write

On Fri, Jul 15, 2016 at 07:16:01PM -0700, Sargun Dhillon wrote: > > > On Thu, 14 Jul 2016, Alexei Starovoitov wrote: > > >On Wed, Jul 13, 2016 at 01:31:57PM -0700, Sargun Dhillon wrote: > >> > >> > >>On Wed, 13 Jul 2016, Alexei Starovoitov wrote:

Re: [RFC PATCH v2 00/26] perf tools: Support uBPF script

On Tue, Jun 28, 2016 at 07:47:53PM +0800, Hekuang wrote: > > > 在 2016/6/27 4:48, Alexei Starovoitov 写道: > >On Sun, Jun 26, 2016 at 11:20:52AM +, He Kuang wrote: > >> bounds check just like ubpf library does. > >hmm. I don't think I suggested to hack

Re: [PATCH net] udp: prevent bugcheck if filter truncates packet too much

On Sat, Jul 09, 2016 at 01:31:40AM +0200, Eric Dumazet wrote: > On Fri, 2016-07-08 at 17:52 +0200, Michal Kubecek wrote: > > If socket filter truncates an udp packet below the length of UDP header > > in udpv6_queue_rcv_skb() or udp_queue_rcv_skb(), it will trigger a > > BUG_ON in

Re: [PATCH v2 1/3] perf/core: Add a tracepoint for perf sampling

On Thu, Aug 04, 2016 at 04:28:53PM +0200, Peter Zijlstra wrote: > On Wed, Aug 03, 2016 at 11:57:05AM -0700, Brendan Gregg wrote: > > > As for pmu tracepoints: if I were to instrument it (although I wasn't > > planning to), I'd put a tracepoint in perf_event_overflow() called > >

Re: [RFC V2 PATCH 00/25] Kernel NET policy

On Wed, Dec 31, 2014 at 08:38:49PM -0500, kan.li...@intel.com wrote: > > Changes since V1: > - Using work queue to set Rx network flow classification rules and search >available NET policy object asynchronously. > - Using RCU lock to replace read-write lock > - Redo performance test and

Re: [PATCH v2 1/3] perf/core: Add a tracepoint for perf sampling

On Thu, Aug 04, 2016 at 09:13:16PM -0700, Brendan Gregg wrote: > On Thu, Aug 4, 2016 at 6:43 PM, Alexei Starovoitov > <alexei.starovoi...@gmail.com> wrote: > > On Thu, Aug 04, 2016 at 04:28:53PM +0200, Peter Zijlstra wrote: > >> On Wed, Aug 03, 2016 at 11:57:05AM

Re: [PATCH v2 1/3] perf/core: Add a tracepoint for perf sampling

On Fri, Aug 05, 2016 at 12:52:09PM +0200, Peter Zijlstra wrote: > > > > Currently overflow_handler is set at event alloc time. If we start > > > > changing it on the fly with atomic xchg(), afaik things shouldn't > > > > break, since each overflow_handler is run to completion and doesn't > > > >

Re: [PATCH v4 1/2] bpf: Add bpf_probe_write BPF helper to be called in tracers (kprobes)

On Fri, Jul 22, 2016 at 05:05:27PM -0700, Sargun Dhillon wrote: > It was tested with the tracex7 program on x86-64. it's my fault to start tracexN tradition that turned out to be cumbersome, let's not continue it. Instead could you rename it to something meaningful? Like test_probe_write_user ?

Re: [RFC PATCH v2 00/26] perf tools: Support uBPF script

On Wed, Jun 29, 2016 at 06:35:12PM +0800, Wangnan (F) wrote: > > > On 2016/6/29 18:15, Hekuang wrote: > >hi > > > >在 2016/6/28 22:57, Alexei Starovoitov 写道: > >> > >> return 0; > >> } > >>@@ -465,7 +465,7 @@ EXPORT_SYMBOL_

Re: Potential issues (security and otherwise) with the current cgroup-bpf API

On Fri, Feb 03, 2017 at 01:07:39PM -0800, Andy Lutomirski wrote: > > Is there any plan to address this? If not, I'll try to write that > patch this weekend. yes. I'm working on 'disallow program override' flag. It got stalled, because netns discussion got stalled. Later today will send a patch

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