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: [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 whic

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

fixed this to work with x86_64 and arm64, but not s390. Cc: Alexei Starovoitov Cc: David S. Miller Cc: Ananth N Mavinakayanahalli Cc: Michael Ellerman Signed-off-by: Naveen N. Rao --- ... + +#ifdef __powerpc__ +#define BPF_KPROBE_READ_RET_IP(ip, ctx){ (ip) = (ctx)->link; }

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 CONFIG_SAMP

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 Cc: David S. Miller Cc: Ananth N Mavinakayanahalli Cc: Michael Ellerman Signed-off-by: Naveen N. Rao --- samples/bpf/Makefile | 11 --- 1 file changed, 4 insertions(+), 7

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 Cc: David S. Miller Cc: Ananth N Mavinakayanahalli Cc: Michael Ellerman Signed-off-by: Naveen N. Rao --- samples/bpf/map_perf_test_user.c | 1 + 1 file changed, 1 insertion(+) diff --git a/samples/bpf

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 overhea

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 > Cc: He Kuang > Cc: Alexei Starovoitov > Cc: Arnaldo Carvalho de Melo > Cc: Brendan Gregg > Cc: Jiri Olsa > Cc: Masami Hiramatsu > Cc: Namhyung Kim > Cc: Peter Zijlstra > Cc: Zefan Li > Cc: pi3or

Re: [PATCH] bpf: doc: "neg" opcode has no operands

On Mon, Mar 28, 2016 at 02:56:47PM -0700, Kees Cook wrote: > From: Dave Anderson > > Fixes a copy-paste-o in the BPF opcode table: "neg" takes no arguments > and thus has no addressing modes. > > Signed-off-by: Dave Anderson > Signed-off-by: Kees Cook Acked-by: Alexei Starovoitov

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

@ 3.60GHz > Kernel : v4.5.0 >MEAN STDVAR > BASE800214.9502853.083 > PRE1 2253846.7009997.014 > PRE2 2257495.5408516.293 > POST 2250896.1008933.921 > > Where 'BASE' is pure p

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

or > the reading is unreliable. > > Signed-off-by: Wang Nan > Cc: He Kuang > Cc: Alexei Starovoitov > Cc: Arnaldo Carvalho de Melo > Cc: Brendan Gregg > Cc: Jiri Olsa > Cc: Masami Hiramatsu > Cc: Namhyung Kim > Cc: Peter Zijlstra > Cc: Zefan Li > Cc: pi3or

Re: [PATCH 3/4] perf core: Prepare writing into ring buffer from end

s test result after this > patch. See [4] for detail experimental setup. > > Considering the stdvar, this patch doesn't hurt performance. > > For the detail of testing method, please refer to [2]. > > [1] http://lkml.kernel.org/g/56f52e83.70...@huawei.com > [2] http://lkml.

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. > > > >

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 net-next] bpf: avoid copying junk bytes in bpf_get_current_comm()

On 3/11/16 10:02 AM, Daniel Borkmann wrote: Would strscpy() help in this case (see 30035e45753b ("string: provide strscpy()"))? I've looked at it too, but 990486c8af04 scared me a little, it's not easily backport-able and mainly I don't think it's faster than strlcpy for small strings like comm

Re: [PATCH net-next] bpf: avoid copying junk bytes in bpf_get_current_comm()

On 3/11/16 2:24 AM, Daniel Borkmann wrote: On 03/10/2016 05:02 AM, Alexei Starovoitov wrote: Lots of places in the kernel use memcpy(buf, comm, TASK_COMM_LEN); but the result is typically passed to print("%s", buf) and extra bytes after zero don't cause any harm. In bp

[PATCH net-next] bpf: avoid copying junk bytes in bpf_get_current_comm()

: introduce current->pid, tgid, uid, gid, comm accessors") Reported-by: Tobias Waldekranz Signed-off-by: Alexei Starovoitov --- Targeting net-next, since it's too late for net. I think it makes sense for stable as well. kernel/bpf/helpers.c | 2 +- 1 file changed, 1 insertion(+), 1 del

Re: [PATCH] bpf: make bpf_stackmap_copy conditionally called

On Thu, Mar 10, 2016 at 02:43:42AM +0100, Arnd Bergmann wrote: > Changing the bpf syscall to use the new bpf_stackmap_copy() helper for > BPF_MAP_TYPE_STACK_TRACE causes a link error when CONFIG_PERF_EVENTS > is disabled: > > kernel/built-in.o: In function `map_lookup_elem': > :(.text+0x7fca4): un

[PATCH net-next 3/3] 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 --- samples/bpf/Makefile | 4 + samples/bpf/map_perf_test_kern.c | 100 + samples/bpf/map_perf_test_user.c | 155

[PATCH net-next 2/3] samples/bpf: stress test bpf_get_stackid

increase stress by also calling bpf_get_stackid() from various *spin* functions Signed-off-by: Alexei Starovoitov --- samples/bpf/spintest_kern.c | 9 + 1 file changed, 9 insertions(+) diff --git a/samples/bpf/spintest_kern.c b/samples/bpf/spintest_kern.c index ef8ac33bb2e9

[PATCH net-next 1/3] samples/bpf: add bpf map stress test

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 --- samples/bpf/Makefile| 4 +++ samples/bpf/spintest_kern.c

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

On Tue, Mar 08, 2016 at 03:31:10PM -0500, David Miller wrote: ... > > Patch 10: stress test for hash 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 > > > > Re

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 invo

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

n the same cpu. Signed-off-by: Alexei Starovoitov --- kernel/bpf/Makefile | 2 +- kernel/bpf/percpu_freelist.c | 100 +++ kernel/bpf/percpu_freelist.h | 31 ++ 3 files changed, 132 insertions(+), 1 deletion(-) create mode 100644 kerne

[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 --- samples/bpf/bpf_load.c | 62 ++ samples/bpf/bpf_load.h | 6 samples/bpf/offwaketime_user.c | 67

[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 --- samples/bpf/bpf_load.c | 5 - 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/samples/bpf/bpf_load.c b

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

can be large and number of map update/delete per second is low, it may make sense to use it. Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 2 + include/uapi/linux/bpf.h | 3 + kernel/bpf/hashtab.c | 240 +-- kernel/bpf/sysca

[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 Acked-by: Daniel Borkmann --- include/linux/bpf.h | 3 +++ kernel/bpf/sys

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

lookup 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

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

Suggested-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- 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 bd3bdf2486a7..76d5a794e426 100644 --- a/kernel/bpf

[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 --- 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 index 7bd9edd02d9b..47bf0858f9e4

[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 --- samples/bpf/bpf_helpers.h | 1 + samples/bpf/bpf_load.c | 3 ++- samples/bpf/fds_example.c | 2 +- samples/bpf/libbpf.c| 5 +++-- samples/bpf/libbpf.h| 2

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

ess test for hash 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 Reported-by: Tom Zanussi Alexei Starovoitov (12): bpf: prevent kprobe+bpf deadl

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 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

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

[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 --- samples/bpf/Makefile | 4 + samples/bpf/map_perf_test_kern.c | 100 + samples/bpf/map_perf_test_user.c | 155

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

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 --- samples/bpf/Makefile| 4 +++ samples/bpf/spintest_kern.c

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

large and number of map update/delete per second is low, it may make sense to use it. Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 3 + kernel/bpf/hashtab.c | 264 ++- kernel/bpf/syscall.c

[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 --- samples/bpf/bpf_load.c | 62 ++ samples/bpf/bpf_load.h | 6 samples/bpf/offwaketime_user.c | 67

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

n the same cpu. Signed-off-by: Alexei Starovoitov --- kernel/bpf/Makefile | 2 +- kernel/bpf/percpu_freelist.c | 81 kernel/bpf/percpu_freelist.h | 31 + 3 files changed, 113 insertions(+), 1 deletion(-) create mode 100644 k

[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 --- samples/bpf/bpf_load.c | 5 - 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/samples/bpf/bpf_load.c b

[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 --- samples/bpf/bpf_helpers.h | 1 + samples/bpf/bpf_load.c | 3 ++- samples/bpf/fds_example.c | 2 +- samples/bpf/libbpf.c| 5 +++-- samples/bpf/libbpf.h| 2

[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 --- 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 index af02f7518c0a..d1e63f48e39c

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

checks Patches 4-7: prepare test infra Patch 8: stress test for hash map infra. It attaches to spin_lock functions and bpf_map_update/delete are called from different contexts (except nmi, which is unsupported by bpf still) Patch 9: map performance test Reported-by: Daniel Wagner Reported-by: To

[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 --- include/linux/bpf.h | 3 +++ kernel/bpf/syscall.c | 13 + kernel/tr

Re: [PATCH net-next 1/3] perf: generalize perf_callchain

On 2/25/16 8:47 AM, Peter Zijlstra wrote: On Wed, Feb 17, 2016 at 07:58:57PM -0800, Alexei Starovoitov wrote: +static inline int perf_callchain_store(struct perf_callchain_entry *entry, u64 ip) { + if (entry->nr < PERF_MAX_STACK_DEPTH) { entry->ip[entry-&g

Re: [PATCH net-next 1/3] perf: generalize perf_callchain

On 2/25/16 6:18 AM, Peter Zijlstra wrote: On Wed, Feb 17, 2016 at 07:58:57PM -0800, Alexei Starovoitov wrote: . avoid walking the stack when there is no room left in the buffer . generalize get_perf_callchain() to be called from bpf helper If it does two things it should be two patches

Re: [PATCH net-next 2/3] bpf: introduce BPF_MAP_TYPE_STACK_TRACE

On 2/25/16 6:23 AM, Peter Zijlstra wrote: + id = hash & (smap->n_buckets - 1); Its not at all clear where the corresponding rcu_read_lock() is at. >+ bucket = rcu_dereference(smap->buckets[id]); bpf programs of all types are always executing under rcu_read_lock(). This is fundamental

Re: [PATCH v2] bpf: grab rcu read lock for bpf_percpu_hash_update

") > Signed-off-by: Sasha Levin thank you. Acked-by: Alexei Starovoitov

Re: [RFC][PATCH 00/10] Add trace event support to eBPF

On Thu, Feb 18, 2016 at 03:27:18PM -0600, Tom Zanussi wrote: > On Tue, 2016-02-16 at 20:51 -0800, Alexei Starovoitov wrote: > > On Tue, Feb 16, 2016 at 04:35:27PM -0600, Tom Zanussi wrote: > > > On Sun, 2016-02-14 at 01:02 +0100, Alexei Starovoitov wrote: > > > > On F

Re: [PATCH] bpf: grab rcu read lock for bpf_percpu_hash_update

On Thu, Feb 18, 2016 at 09:56:22PM -0500, Sasha Levin wrote: > bpf_percpu_hash_update() expects rcu lock to be held and warns if it's not, > which pointed out a missing rcu read lock. > > Fixes: 15a07b338 ("bpf: add lookup/update support for per-cpu hash and array > maps") > Signed-off-by: Sasha

[PATCH net-next 3/3] samples/bpf: offwaketime example

y were woken up. The combined stacks, task names, and total time is summarized in kernel context for efficiency. Example: $ sudo ./offwaketime | flamegraph.pl > demo.svg Open demo.svg in the browser as FlameGraph visualization. Signed-off-by: Alexei Starovoitov --- samples/bpf/Makefi

[PATCH net-next 0/3] bpf_get_stackid() and stack_trace map

hash_futex 1.05% sched_bench [kernel.vmlinux][k] do_futex 1.05% sched_bench [kernel.vmlinux][k] get_futex_key_refs.isra.13 The hotest part of bpf_get_stackid() is inlined jhash2, so we may consider using some faster hash in the future, but it's good enough for now. Alexe

[PATCH net-next 2/3] bpf: introduce BPF_MAP_TYPE_STACK_TRACE

ata (including other stackid) and used as a key into maps. Userspace will access stackmap using standard lookup/delete syscall commands to retrieve full stack trace for given stackid. Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 21 + ker

[PATCH net-next 1/3] perf: generalize perf_callchain

. avoid walking the stack when there is no room left in the buffer . generalize get_perf_callchain() to be called from bpf helper Signed-off-by: Alexei Starovoitov --- arch/x86/include/asm/stacktrace.h | 2 +- arch/x86/kernel/cpu/perf_event.c | 4 ++-- arch/x86/kernel/dumpstack.c | 6

Re: [RFC][PATCH 00/10] Add trace event support to eBPF

On Tue, Feb 16, 2016 at 04:35:27PM -0600, Tom Zanussi wrote: > On Sun, 2016-02-14 at 01:02 +0100, Alexei Starovoitov wrote: > > On Fri, Feb 12, 2016 at 10:11:18AM -0600, Tom Zanussi wrote: > > this hist triggers belong in the kernel. BPF already can do > > way more co

Re: [RFC][PATCH 00/10] Add trace event support to eBPF

On Fri, Feb 12, 2016 at 10:11:18AM -0600, Tom Zanussi wrote: > Hi, > > As promised in previous threads, this patchset shares some common > functionality with the hist triggers code and enables trace events to > be accessed from eBPF programs. great that you've started working on BPF! > It needs

Re: [tip:perf/urgent] perf/bpf: Convert perf_event_array to use struct file

On Fri, Jan 29, 2016 at 03:28:40AM -0800, tip-bot for Alexei Starovoitov wrote: > Commit-ID: e03e7ee34fdd1c3ef494949a75cb8c61c7265fa9 > Gitweb: http://git.kernel.org/tip/e03e7ee34fdd1c3ef494949a75cb8c61c7265fa9 > Author: Alexei Starovoitov > AuthorDate: Mon, 25 Jan 2016 20

[tip:perf/urgent] perf/bpf: Convert perf_event_array to use struct file

Commit-ID: e03e7ee34fdd1c3ef494949a75cb8c61c7265fa9 Gitweb: http://git.kernel.org/tip/e03e7ee34fdd1c3ef494949a75cb8c61c7265fa9 Author: Alexei Starovoitov AuthorDate: Mon, 25 Jan 2016 20:59:49 -0800 Committer: Ingo Molnar CommitDate: Fri, 29 Jan 2016 08:35:25 +0100 perf/bpf: Convert

Re: [RFC PATCH v2 1/3] getcpu_cache system call: cache CPU number of running thread

On Wed, Jan 27, 2016 at 11:54:41AM -0500, Mathieu Desnoyers wrote: > Expose a new system call allowing threads to register one userspace > memory area where to store the CPU number on which the calling thread is > running. Scheduler migration sets the TIF_NOTIFY_RESUME flag on the > current thread.

Re: [PATCH v2] perf: Synchronously cleanup child events

On Wed, Jan 27, 2016 at 10:58:22AM +0100, Peter Zijlstra wrote: > > > Meaning there gotta be always a user space process > > that will be holding perf_event FDs. > > By using fget() the BPF array thing will hold the FDs, right? I mean > once you do a full fget() userspace can go and kill itself,

Re: make samples/bpf/ using gcc instead of clang/llvm

On Tue, Jan 26, 2016 at 09:51:54PM -0800, Joel Fernandes wrote: > Hi Brendan, Alexei, > > I noticed your patch fixing the $subject issue. > > https://patchwork.ozlabs.org/patch/471118/ > > However, I still see make samples/bpf/ using gcc instead of clang. > > Here's a verbose kbuild output of m

Re: [PATCH v2] perf: Synchronously cleanup child events

On Tue, Jan 26, 2016 at 06:24:25PM +0100, Peter Zijlstra wrote: > On Tue, Jan 26, 2016 at 05:16:37PM +0100, Peter Zijlstra wrote: > > > +struct file *perf_event_get(unsigned int fd) > > > { > > > + struct file *file; > > > > > > + file = fget_raw(fd); > > > > fget_raw() to guarantee the return

Re: [PATCH v2] perf: Synchronously cleanup child events

++--- > 2 files changed, 150 insertions(+), 157 deletions(-) I think I understand what you're trying to do and the patch looks good to me. As far as BPF side I did the following... does it match the model you outlined above? I did basic testing and it looks fine.

Re: [PATCH 0/5] perf core: Read from overwrite ring buffer

On Mon, Jan 25, 2016 at 08:33:48AM +, Wang Nan wrote: > This is the v3 of this series. Compare with v2, tailsize method is > removed, ioctl command PERF_EVENT_IOC_PAUSE_OUTPUT is changed to > _IOW('$', 9, __u32) since it has an input value, commit message > is slightly adjusted. > > New test r

Re: [PATCH v2] perf: Synchronously cleanup child events

On Fri, Jan 22, 2016 at 01:38:47PM +0100, Peter Zijlstra wrote: > On Fri, Jan 22, 2016 at 01:35:40PM +0200, Alexander Shishkin wrote: > > Peter Zijlstra writes: > > > > > So I think there's a number of problems still :-( I've been looking at how perf_event->owner is handled and couldn't figure o

Re: [PATCH 0/6] perf core: Read from overwrite ring buffer

On Fri, Jan 22, 2016 at 12:13:48PM +, Wang Nan wrote: > This is v2 of this series. > > Compare with v1: > > Fixes several bugs in v1. > > Corresponsing perf has finished and can be found from: > > https://git.kernel.org/cgit/linux/kernel/git/pi3orama/linux.git/ > branch: perf/overwrite-b

Re: [PATCH 1/6] perf core: Introduce new ioctl options to pause and resume ring buffer

off all events attached to this ring buffer. > This patch is for supporting overwritable ring buffer with TAILSIZE > selected. TAILSIZE is dropped. pls adjust commit log. > Signed-off-by: Wang Nan > Cc: He Kuang > Cc: Alexei Starovoitov > Cc: Arnaldo Carvalho de Melo > Cc:

Re: clang --target=bpf missing on f23 was: Re: [PATCH 1/2] perf test: Add libbpf relocation checker

On Fri, Jan 22, 2016 at 12:35:42PM -0500, Adam Jackson wrote: > On Fri, 2016-01-22 at 14:22 -0300, Arnaldo Carvalho de Melo wrote: > > > the 'bpf' target for clang is being used together with perf to > > build scriptlets into object code that then gets uploaded to the kernel > > via sys_bpf(),

Re: [PATCH 23/33] x86/asm/bpf: Create stack frames in bpf_jit.S

On Fri, Jan 22, 2016 at 11:36:14AM -0600, Josh Poimboeuf wrote: > On Fri, Jan 22, 2016 at 09:18:23AM -0800, Alexei Starovoitov wrote: > > On Fri, Jan 22, 2016 at 09:58:04AM -0600, Josh Poimboeuf wrote: > > > On Thu, Jan 21, 2016 at 08:18:46PM -0800, Alexei Starovoitov wrote: >

Re: [RFC PATCH 1/1] seccomp: provide information about the previous syscall

On Fri, Jan 22, 2016 at 03:30:00PM +0900, Daniel Sangorrin wrote: > This patch allows applications to restrict the order in which > its system calls may be requested. In order to do that, we > provide seccomp-BPF scripts with information about the > previous system call requested. > > An example u

Re: [PATCH 31/33] bpf: Add __bpf_prog_run() to stacktool whitelist

On Thu, Jan 21, 2016 at 10:13:02PM -0600, Josh Poimboeuf wrote: > On Thu, Jan 21, 2016 at 06:55:41PM -0800, Alexei Starovoitov wrote: > > On Thu, Jan 21, 2016 at 04:49:35PM -0600, Josh Poimboeuf wrote: > > > stacktool reports the following false positive warnings: > > >

Re: [PATCH 23/33] x86/asm/bpf: Create stack frames in bpf_jit.S

On Fri, Jan 22, 2016 at 09:58:04AM -0600, Josh Poimboeuf wrote: > On Thu, Jan 21, 2016 at 08:18:46PM -0800, Alexei Starovoitov wrote: > > On Thu, Jan 21, 2016 at 09:55:31PM -0600, Josh Poimboeuf wrote: > > > On Thu, Jan 21, 2016 at 06:44:28PM -0800, Alexei Starovoitov wrote: >

Re: [PATCH 2/2] perf bpf: Check relocation target section

return -LIBBPF_ERRNO__RELOC; > + } May be 'pr_err' instead of 'pr_warning', since such program will fail to load by kernel anyway. Looks good otherwise. Acked-by: Alexei Starovoitov

Re: [PATCH 1/2] perf test: Add libbpf relocation checker

On Fri, Jan 22, 2016 at 12:40:50PM -0300, Arnaldo Carvalho de Melo wrote: > [root@jouet ~]# llc --version > LLVM (http://llvm.org/): > LLVM version 3.7.0 > Optimized build. > Built Dec 4 2015 (15:49:18). > Default target: x86_64-redhat-linux-gnu > Host CPU: broadwell > > Registered Ta

Re: [PATCH 23/33] x86/asm/bpf: Create stack frames in bpf_jit.S

On Thu, Jan 21, 2016 at 09:55:31PM -0600, Josh Poimboeuf wrote: > On Thu, Jan 21, 2016 at 06:44:28PM -0800, Alexei Starovoitov wrote: > > On Thu, Jan 21, 2016 at 04:49:27PM -0600, Josh Poimboeuf wrote: > > > bpf_jit.S has several callable non-leaf functions

Re: [PATCH 0/6] perf core: Read from overwrite ring buffer

On Fri, Jan 22, 2016 at 10:21:19AM +0800, Wangnan (F) wrote: > > > On 2016/1/21 14:51, Wangnan (F) wrote: > > > > > >On 2016/1/20 10:20, Alexei Starovoitov wrote: > >>On Wed, Jan 20, 2016 at 09:37:42AM +0800, Wangnan (F) wrote: > >>> > >>&

Re: [PATCH 31/33] bpf: Add __bpf_prog_run() to stacktool whitelist

On Thu, Jan 21, 2016 at 04:49:35PM -0600, Josh Poimboeuf wrote: > stacktool reports the following false positive warnings: > > stacktool: kernel/bpf/core.o: __bpf_prog_run()+0x5c: sibling call from > callable instruction with changed frame pointer > stacktool: kernel/bpf/core.o: __bpf_prog_ru

Re: [PATCH 23/33] x86/asm/bpf: Create stack frames in bpf_jit.S

E_POINTER is enabled. > > Signed-off-by: Josh Poimboeuf > Cc: Alexei Starovoitov > Cc: net...@vger.kernel.org > --- > arch/x86/net/bpf_jit.S | 9 +++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/net/bpf_jit.S b/arch/x86/net/bpf_jit.S >

Re: [PATCH v2] perf: Synchronously cleanup child events

On Wed, Jan 20, 2016 at 09:32:22AM +0100, Peter Zijlstra wrote: > On Tue, Jan 19, 2016 at 01:58:19PM -0800, Alexei Starovoitov wrote: > > On Tue, Jan 19, 2016 at 09:05:58PM +0100, Peter Zijlstra wrote: > > > > The most obvious place that generates such magical references w

Re: [PATCH] net: filter: make JITs zero A for SKF_AD_ALU_XOR_X

> Acked-by: Daniel Borkmann good catch indeed. Classic bpf jits didn't have much love. Great to see this work. Acked-by: Alexei Starovoitov -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

Re: [PATCH 08/10] bpf samples: Add utils.[ch] for using BPF

On Fri, Dec 18, 2015 at 03:04:00PM +0800, Wangnan (F) wrote: > > >>However, linux/err.h is not a part of uapi. To make libbpf work, one has to > >>create its > >>own err.h. > >Why tools/include/linux/err.h is not suitable for everyone? > > > >>Now I'm thinking provide LIBBPF_{IS_ERR,PTR_ERR}(), i

Re: [PATCH 4/6] bpf: hash: convert per-hashtable lock into per-bucket bit spinlock

On Wed, Dec 16, 2015 at 02:58:08PM +0800, Ming Lei wrote: > On Wed, Dec 16, 2015 at 1:01 PM, Yang Shi wrote: > > > > > I recalled Steven confirmed raw_spin_lock has the lockdep benefit too in the > > patch review for changing to raw lock. > > > > Please check this thread out > > http://lists.ope

Re: [PATCH 08/10] bpf samples: Add utils.[ch] for using BPF

On Fri, Dec 18, 2015 at 09:47:11AM +0800, Wangnan (F) wrote: > > This is a limitation in tools/lib/bpf/libbpf.h, which has a #include > > in its header. > > libbpf.h requires this include because its API uses ERR_PTR() to encode > error code. > For example, when calling bpf_object__open(), calle

Re: [PATCH 08/10] bpf samples: Add utils.[ch] for using BPF

On Thu, Dec 17, 2015 at 05:23:12AM +, Wang Nan wrote: > We are going to uses libbpf to replace old libbpf.[ch] and > bpf_load.[ch]. This is the first patch of this work. In this patch, > several macros and helpers in libbpf.[ch] and bpf_load.[ch] are > merged into utils.[ch]. utils.[ch] utilize

Re: [PATCH 5/6] bpf: hash: avoid to call kmalloc() in eBPF prog

On Tue, Dec 15, 2015 at 07:21:03PM +0800, Ming Lei wrote: > kmalloc() is often a bit time-consuming, also > one atomic counter has to be used to track the total > allocated elements, which is also not good. > > This patch pre-allocates element pool in htab_map_alloc(), > then use percpu_ida to all

Re: [PATCH 4/6] bpf: hash: convert per-hashtable lock into per-bucket bit spinlock

On Tue, Dec 15, 2015 at 07:21:02PM +0800, Ming Lei wrote: > Both htab_map_update_elem() and htab_map_delete_elem() can be > called from eBPF program, and they may be in kernel hot path, > so it isn't efficient to use a per-hashtable lock in this two > helpers. > > The per-hashtable spinlock is use

Re: [PATCH v4 09/16] perf tools: Enable indices setting syntax for BPF maps

On Mon, Dec 14, 2015 at 12:39:40PM +0800, Wangnan (F) wrote: > > And what do you think about the BPF function prototype? Should we put them > into kernel headers? What about:: > +#define DEFINE_BPF_FUNC(rettype, name, arglist...) static rettype > (*name)(arglist) = (void *)BPF_FUNC_##name tld

Re: [PATCH v4 09/16] perf tools: Enable indices setting syntax for BPF maps

On Mon, Dec 14, 2015 at 11:27:36AM +0800, Wangnan (F) wrote: > > > On 2015/12/12 2:21, Alexei Starovoitov wrote: > >On Fri, Dec 11, 2015 at 08:39:35PM +0800, pi3orama wrote: > >>>static u64 (*bpf_ktime_get_ns)(void) = > >>> (void *)5; > >>>

Re: [PATCH v4 09/16] perf tools: Enable indices setting syntax for BPF maps

On Fri, Dec 11, 2015 at 08:39:35PM +0800, pi3orama wrote: > > static u64 (*bpf_ktime_get_ns)(void) = > > (void *)5; > > static int (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) = > > (void *)6; > > static int (*bpf_get_smp_processor_id)(void) = > > (void *)8; > > static int (*

Re: [PATCH] bpf: constify bpf_verifier_ops structure

On Fri, Dec 11, 2015 at 01:12:56PM -0500, Steven Rostedt wrote: > On Fri, 11 Dec 2015 18:35:59 +0100 > Julia Lawall wrote: > > > This bpf_verifier_ops structure is never modified, like the other > > bpf_verifier_ops structures, so declare it as const. > > > > Done with the help of Coccinelle. >

Re: [PATCH] bpf: constify bpf_verifier_ops structure

On Fri, Dec 11, 2015 at 06:35:59PM +0100, Julia Lawall wrote: > This bpf_verifier_ops structure is never modified, like the other > bpf_verifier_ops structures, so declare it as const. > > Done with the help of Coccinelle. > > Signed-off-by: Julia Lawall Acked-by: Alexei

Re: use-after-free in __perf_install_in_context

On Thu, Dec 10, 2015 at 10:02:51AM +0100, Peter Zijlstra wrote: > On Wed, Dec 09, 2015 at 07:54:35PM -0800, Alexei Starovoitov wrote: > > Freeing memory is a requirement regardless. > > Even when kernel running with kasan, there must be a way to stop > > stack collection

Re: use-after-free in __perf_install_in_context

On Wed, Dec 09, 2015 at 10:17:17AM +0100, Dmitry Vyukov wrote: > > We would happily share this code with other subsystems, or even better > reuse an existing solutions. But to the best of my knowledge there is > no such existing solution, and I still know basically nothing about > what you were ha

Re: [PATCH perf/core 00/22] perf refcnt debugger API and fixes

On Wed, Dec 09, 2015 at 10:41:38AM -0300, Arnaldo Carvalho de Melo wrote: > Em Wed, Dec 09, 2015 at 11:10:48AM +0900, Masami Hiramatsu escreveu: > > Hi Arnaldo, > > > > Here is a series of patches for perf refcnt debugger and > > some fixes. > > > > In this series I've replaced all atomic referen

Re: use-after-free in __perf_install_in_context

On Tue, Dec 08, 2015 at 07:35:20PM +0100, Dmitry Vyukov wrote: > On Tue, Dec 8, 2015 at 7:05 PM, Alexei Starovoitov > wrote: > > On Tue, Dec 08, 2015 at 06:56:23PM +0100, Dmitry Vyukov wrote: > >> On Tue, Dec 8, 2015 at 6:54 PM, Alexei Starovoitov > >> wrote: > &

Re: use-after-free in __perf_install_in_context

On Tue, Dec 08, 2015 at 06:56:23PM +0100, Dmitry Vyukov wrote: > On Tue, Dec 8, 2015 at 6:54 PM, Alexei Starovoitov > wrote: > > On Tue, Dec 08, 2015 at 05:12:04PM +0100, Dmitry Vyukov wrote: > >> On Tue, Dec 8, 2015 at 4:24 AM, Alexei Starovoitov > >> wrote: > &

Re: use-after-free in __perf_install_in_context

On Tue, Dec 08, 2015 at 05:12:04PM +0100, Dmitry Vyukov wrote: > On Tue, Dec 8, 2015 at 4:24 AM, Alexei Starovoitov > wrote: > > On Mon, Dec 07, 2015 at 05:09:21PM +0100, Dmitry Vyukov wrote: > >> > So it would be _awesome_ if we could somehow extend this callchain to >

Re: use-after-free in __perf_install_in_context

On Mon, Dec 07, 2015 at 05:09:21PM +0100, Dmitry Vyukov wrote: > > So it would be _awesome_ if we could somehow extend this callchain to > > include the site that calls call_rcu(). > > We have a patch for KASAN in works that adds so-called stack depot > which allows to map a stack trace onto uint3

<    6   7   8   9   10   11   12   13   14   15   >