* [PATCH 0/2] perf bpf: Fix relocation error @ 2016-01-22 9:27 Wang Nan 2016-01-22 9:27 ` [PATCH 1/2] perf test: Add libbpf relocation checker Wang Nan 2016-01-22 9:27 ` [PATCH 2/2] perf bpf: Check relocation target section Wang Nan 0 siblings, 2 replies; 14+ messages in thread From: Wang Nan @ 2016-01-22 9:27 UTC (permalink / raw) To: ast, acme Cc: linux-kernel, Wang Nan, Arnaldo Carvalho de Melo, Daniel Borkmann, Li Zefan, pi3orama Alexei notices me about a bug in llvm [1]. Because of this bug, even a normal BPF program can generate incorrect (or redundant) relocation information. Patch 1 adds a new test case about it (use an buggy BPF script, should fail even LLVM's bug is fixed). Since it is the first test case expected to be fail, test framework is slightly adjusted. Patch 2 adds the checker. [1] https://llvm.org/bugs/show_bug.cgi?id=26243 Wang Nan (2): perf test: Add libbpf relocation checker perf bpf: Check relocation target section tools/lib/bpf/libbpf.c | 34 +++++++++++------- tools/perf/Makefile.perf | 2 +- tools/perf/tests/.gitignore | 1 + tools/perf/tests/Build | 9 ++++- tools/perf/tests/bpf-script-test-relocation.c | 50 +++++++++++++++++++++++++++ tools/perf/tests/bpf.c | 26 +++++++++++--- tools/perf/tests/llvm.c | 17 ++++++--- tools/perf/tests/llvm.h | 5 ++- 8 files changed, 120 insertions(+), 24 deletions(-) create mode 100644 tools/perf/tests/bpf-script-test-relocation.c Cc: Alexei Starovoitov <ast@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Li Zefan <lizefan@huawei.com> Cc: pi3orama@163.com -- 1.8.3.4 ^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH 1/2] perf test: Add libbpf relocation checker 2016-01-22 9:27 [PATCH 0/2] perf bpf: Fix relocation error Wang Nan @ 2016-01-22 9:27 ` Wang Nan 2016-01-22 15:40 ` Arnaldo Carvalho de Melo 2016-01-22 9:27 ` [PATCH 2/2] perf bpf: Check relocation target section Wang Nan 1 sibling, 1 reply; 14+ messages in thread From: Wang Nan @ 2016-01-22 9:27 UTC (permalink / raw) To: ast, acme Cc: linux-kernel, Wang Nan, Arnaldo Carvalho de Melo, Daniel Borkmann, Li Zefan, pi3orama There's a bug in LLVM that it can generate unneeded relocation information. See [1] and [2]. Libbpf should check the target section of a relocation symbol. This patch adds a testcase which reference a global variable (BPF doesn't support global variable). Before fixing libbpf, the new test case can be loaded into kernel, the global variable acts like the first map. It is incorrect. Result: # ~/perf test BPF 37: Test BPF filter : 37.1: Test basic BPF filtering : Ok 37.2: Test BPF prologue generation : Ok 37.3: Test BPF relocation checker : FAILED! # ~/perf test -v BPF ... libbpf: loading object '[bpf_relocation_test]' from buffer libbpf: section .strtab, size 126, link 0, flags 0, type=3 libbpf: section .text, size 0, link 0, flags 6, type=1 libbpf: section .data, size 0, link 0, flags 3, type=1 libbpf: section .bss, size 0, link 0, flags 3, type=8 libbpf: section func=sys_write, size 104, link 0, flags 6, type=1 libbpf: found program func=sys_write libbpf: section .relfunc=sys_write, size 16, link 10, flags 0, type=9 libbpf: section maps, size 16, link 0, flags 3, type=1 libbpf: maps in [bpf_relocation_test]: 16 bytes libbpf: section license, size 4, link 0, flags 3, type=1 libbpf: license of [bpf_relocation_test] is GPL libbpf: section version, size 4, link 0, flags 3, type=1 libbpf: kernel version of [bpf_relocation_test] is 40400 libbpf: section .symtab, size 144, link 1, flags 0, type=2 libbpf: map 0 is "my_table" libbpf: collecting relocating info for: 'func=sys_write' libbpf: relocation: insn_idx=7 Success unexpectedly: libbpf error when dealing with relocation test child finished with -1 ---- end ---- Test BPF filter subtest 2: FAILED! [1] https://llvm.org/bugs/show_bug.cgi?id=26243 [2] https://patchwork.ozlabs.org/patch/571385/ Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Li Zefan <lizefan@huawei.com> Cc: pi3orama@163.com --- tools/perf/Makefile.perf | 2 +- tools/perf/tests/.gitignore | 1 + tools/perf/tests/Build | 9 ++++- tools/perf/tests/bpf-script-test-relocation.c | 50 +++++++++++++++++++++++++++ tools/perf/tests/bpf.c | 26 +++++++++++--- tools/perf/tests/llvm.c | 17 ++++++--- tools/perf/tests/llvm.h | 5 ++- 7 files changed, 98 insertions(+), 12 deletions(-) create mode 100644 tools/perf/tests/bpf-script-test-relocation.c diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index 5d34815..97ce869 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -618,7 +618,7 @@ clean: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(call QUIET_CLEAN, core-progs) $(RM) $(ALL_PROGRAMS) perf perf-read-vdso32 perf-read-vdsox32 $(call QUIET_CLEAN, core-gen) $(RM) *.spec *.pyc *.pyo */*.pyc */*.pyo $(OUTPUT)common-cmds.h TAGS tags cscope* $(OUTPUT)PERF-VERSION-FILE $(OUTPUT)FEATURE-DUMP $(OUTPUT)util/*-bison* $(OUTPUT)util/*-flex* \ $(OUTPUT)util/intel-pt-decoder/inat-tables.c $(OUTPUT)fixdep \ - $(OUTPUT)tests/llvm-src-{base,kbuild,prologue}.c + $(OUTPUT)tests/llvm-src-{base,kbuild,prologue,relocation}.c $(QUIET_SUBDIR0)Documentation $(QUIET_SUBDIR1) clean $(python-clean) diff --git a/tools/perf/tests/.gitignore b/tools/perf/tests/.gitignore index bf016c4..8cc30e7 100644 --- a/tools/perf/tests/.gitignore +++ b/tools/perf/tests/.gitignore @@ -1,3 +1,4 @@ llvm-src-base.c llvm-src-kbuild.c llvm-src-prologue.c +llvm-src-relocation.c diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build index 614899b..1ba628e 100644 --- a/tools/perf/tests/Build +++ b/tools/perf/tests/Build @@ -31,7 +31,7 @@ perf-y += sample-parsing.o perf-y += parse-no-sample-id-all.o perf-y += kmod-path.o perf-y += thread-map.o -perf-y += llvm.o llvm-src-base.o llvm-src-kbuild.o llvm-src-prologue.o +perf-y += llvm.o llvm-src-base.o llvm-src-kbuild.o llvm-src-prologue.o llvm-src-relocation.o perf-y += bpf.o perf-y += topology.o perf-y += cpumap.o @@ -59,6 +59,13 @@ $(OUTPUT)tests/llvm-src-prologue.c: tests/bpf-script-test-prologue.c tests/Build $(Q)sed -e 's/"/\\"/g' -e 's/\(.*\)/"\1\\n"/g' $< >> $@ $(Q)echo ';' >> $@ +$(OUTPUT)tests/llvm-src-relocation.c: tests/bpf-script-test-relocation.c tests/Build + $(call rule_mkdir) + $(Q)echo '#include <tests/llvm.h>' > $@ + $(Q)echo 'const char test_llvm__bpf_test_relocation[] =' >> $@ + $(Q)sed -e 's/"/\\"/g' -e 's/\(.*\)/"\1\\n"/g' $< >> $@ + $(Q)echo ';' >> $@ + ifeq ($(ARCH),$(filter $(ARCH),x86 arm arm64)) perf-$(CONFIG_DWARF_UNWIND) += dwarf-unwind.o endif diff --git a/tools/perf/tests/bpf-script-test-relocation.c b/tools/perf/tests/bpf-script-test-relocation.c new file mode 100644 index 0000000..93af774 --- /dev/null +++ b/tools/perf/tests/bpf-script-test-relocation.c @@ -0,0 +1,50 @@ +/* + * bpf-script-test-relocation.c + * Test BPF loader checking relocation + */ +#ifndef LINUX_VERSION_CODE +# error Need LINUX_VERSION_CODE +# error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig' +#endif +#define BPF_ANY 0 +#define BPF_MAP_TYPE_ARRAY 2 +#define BPF_FUNC_map_lookup_elem 1 +#define BPF_FUNC_map_update_elem 2 + +static void *(*bpf_map_lookup_elem)(void *map, void *key) = + (void *) BPF_FUNC_map_lookup_elem; +static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) = + (void *) BPF_FUNC_map_update_elem; + +struct bpf_map_def { + unsigned int type; + unsigned int key_size; + unsigned int value_size; + unsigned int max_entries; +}; + +#define SEC(NAME) __attribute__((section(NAME), used)) +struct bpf_map_def SEC("maps") my_table = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 1, +}; + +int this_is_a_global_val; + +SEC("func=sys_write") +int bpf_func__sys_write(void *ctx) +{ + int key = 0; + int value = 0; + + /* + * Incorrect relocation. Should not allow this program be + * loaded into kernel. + */ + bpf_map_update_elem(&this_is_a_global_val, &key, &value, 0); + return 0; +} +char _license[] SEC("license") = "GPL"; +int _version SEC("version") = LINUX_VERSION_CODE; diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c index 33689a0..952ca99 100644 --- a/tools/perf/tests/bpf.c +++ b/tools/perf/tests/bpf.c @@ -71,6 +71,15 @@ static struct { (NR_ITERS + 1) / 4, }, #endif + { + LLVM_TESTCASE_BPF_RELOCATION, + "Test BPF relocation checker", + "[bpf_relocation_test]", + "fix 'perf test LLVM' first", + "libbpf error when dealing with relocation", + NULL, + 0, + }, }; static int do_test(struct bpf_object *obj, int (*func)(void), @@ -190,7 +199,7 @@ static int __test__bpf(int idx) ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz, bpf_testcase_table[idx].prog_id, - true); + true, NULL); if (ret != TEST_OK || !obj_buf || !obj_buf_sz) { pr_debug("Unable to get BPF object, %s\n", bpf_testcase_table[idx].msg_compile_fail); @@ -202,14 +211,21 @@ static int __test__bpf(int idx) obj = prepare_bpf(obj_buf, obj_buf_sz, bpf_testcase_table[idx].name); - if (!obj) { + if ((!!bpf_testcase_table[idx].target_func) != (!!obj)) { + if (!obj) + pr_debug("Fail to load BPF object: %s\n", + bpf_testcase_table[idx].msg_load_fail); + else + pr_debug("Success unexpectedly: %s\n", + bpf_testcase_table[idx].msg_load_fail); ret = TEST_FAIL; goto out; } - ret = do_test(obj, - bpf_testcase_table[idx].target_func, - bpf_testcase_table[idx].expect_result); + if (obj) + ret = do_test(obj, + bpf_testcase_table[idx].target_func, + bpf_testcase_table[idx].expect_result); out: bpf__clear(); return ret; diff --git a/tools/perf/tests/llvm.c b/tools/perf/tests/llvm.c index 06f45c1..70edcdf 100644 --- a/tools/perf/tests/llvm.c +++ b/tools/perf/tests/llvm.c @@ -35,6 +35,7 @@ static int test__bpf_parsing(void *obj_buf __maybe_unused, static struct { const char *source; const char *desc; + bool should_load_fail; } bpf_source_table[__LLVM_TESTCASE_MAX] = { [LLVM_TESTCASE_BASE] = { .source = test_llvm__bpf_base_prog, @@ -48,14 +49,19 @@ static struct { .source = test_llvm__bpf_test_prologue_prog, .desc = "Compile source for BPF prologue generation test", }, + [LLVM_TESTCASE_BPF_RELOCATION] = { + .source = test_llvm__bpf_test_relocation, + .desc = "Compile source for BPF relocation test", + .should_load_fail = true, + }, }; - int test_llvm__fetch_bpf_obj(void **p_obj_buf, size_t *p_obj_buf_sz, enum test_llvm__testcase idx, - bool force) + bool force, + bool *should_load_fail) { const char *source; const char *desc; @@ -68,6 +74,8 @@ test_llvm__fetch_bpf_obj(void **p_obj_buf, source = bpf_source_table[idx].source; desc = bpf_source_table[idx].desc; + if (should_load_fail) + *should_load_fail = bpf_source_table[idx].should_load_fail; perf_config(perf_config_cb, NULL); @@ -136,14 +144,15 @@ int test__llvm(int subtest) int ret; void *obj_buf = NULL; size_t obj_buf_sz = 0; + bool should_load_fail = false; if ((subtest < 0) || (subtest >= __LLVM_TESTCASE_MAX)) return TEST_FAIL; ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz, - subtest, false); + subtest, false, &should_load_fail); - if (ret == TEST_OK) { + if (ret == TEST_OK && !should_load_fail) { ret = test__bpf_parsing(obj_buf, obj_buf_sz); if (ret != TEST_OK) { pr_debug("Failed to parse test case '%s'\n", diff --git a/tools/perf/tests/llvm.h b/tools/perf/tests/llvm.h index 5150b4d..0eaa604 100644 --- a/tools/perf/tests/llvm.h +++ b/tools/perf/tests/llvm.h @@ -7,14 +7,17 @@ extern const char test_llvm__bpf_base_prog[]; extern const char test_llvm__bpf_test_kbuild_prog[]; extern const char test_llvm__bpf_test_prologue_prog[]; +extern const char test_llvm__bpf_test_relocation[]; enum test_llvm__testcase { LLVM_TESTCASE_BASE, LLVM_TESTCASE_KBUILD, LLVM_TESTCASE_BPF_PROLOGUE, + LLVM_TESTCASE_BPF_RELOCATION, __LLVM_TESTCASE_MAX, }; int test_llvm__fetch_bpf_obj(void **p_obj_buf, size_t *p_obj_buf_sz, - enum test_llvm__testcase index, bool force); + enum test_llvm__testcase index, bool force, + bool *should_load_fail); #endif -- 1.8.3.4 ^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH 1/2] perf test: Add libbpf relocation checker 2016-01-22 9:27 ` [PATCH 1/2] perf test: Add libbpf relocation checker Wang Nan @ 2016-01-22 15:40 ` Arnaldo Carvalho de Melo 2016-01-22 17:07 ` Alexei Starovoitov 0 siblings, 1 reply; 14+ messages in thread From: Arnaldo Carvalho de Melo @ 2016-01-22 15:40 UTC (permalink / raw) To: Wang Nan; +Cc: ast, linux-kernel, Daniel Borkmann, Li Zefan, pi3orama Em Fri, Jan 22, 2016 at 09:27:20AM +0000, Wang Nan escreveu: > There's a bug in LLVM that it can generate unneeded relocation > information. See [1] and [2]. Libbpf should check the target section > of a relocation symbol. > > This patch adds a testcase which reference a global variable (BPF > doesn't support global variable). Before fixing libbpf, the new test > case can be loaded into kernel, the global variable acts like the first > map. It is incorrect. > > Result: > # ~/perf test BPF > 37: Test BPF filter : > 37.1: Test basic BPF filtering : Ok > 37.2: Test BPF prologue generation : Ok > 37.3: Test BPF relocation checker : FAILED! So I just got a new notebook, a t450s (heya, will be able to test Intel PT, etc) and installed fedora 23 on it, cool, there is clang/llvm in it! And furthermore: [root@jouet ~]# clang --version clang version 3.7.0 (tags/RELEASE_370/final) Target: x86_64-redhat-linux-gnu Thread model: posix [root@jouet ~]# Seems to be the one we need! But... [root@jouet ~]# perf test bpf 37: Test BPF filter : 37.1: Test basic BPF filtering : Skip 37.2: Test BPF prologue generation : Skip [root@jouet ~]# oh well... >From 'perf test -v bpf': ' | $CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS -DLINUX_VERSION_CODE=$LINUX_VERSION_CODE $CLANG_OPTIONS $KERNEL_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c "$CLANG_SOURCE" -target bpf -O2 -o - error: unable to create target: 'No available targets are compatible with this triple, see -version for the available targets.' ---- And after googling 'list clang supported target' [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 Targets: aarch64 - AArch64 (little endian) aarch64_be - AArch64 (big endian) amdgcn - AMD GCN GPUs arm - ARM arm64 - ARM64 (little endian) armeb - ARM (big endian) cpp - C++ backend nvptx - NVIDIA PTX 32-bit nvptx64 - NVIDIA PTX 64-bit ppc32 - PowerPC 32 ppc64 - PowerPC 64 ppc64le - PowerPC 64 LE r600 - AMD GPUs HD2XXX-HD6XXX systemz - SystemZ thumb - Thumb thumbeb - Thumb (big endian) x86 - 32-bit X86: Pentium-Pro and above x86-64 - 64-bit X86: EM64T and AMD64 [root@jouet ~]# Oops, no bpf, so the good thing is that if we uninstall clang and try that test again: [root@jouet ~]# dnf remove clang llvm Dependencies resolved. ============================================================== Package Arch Version Repository Size ============================================================== Removing: clang x86_64 3.7.0-3.fc23 @updates 45 M clang-libs x86_64 3.7.0-3.fc23 @updates 14 M gcc-c++ x86_64 5.3.1-2.fc23 @updates 24 M libstdc++-devel x86_64 5.3.1-2.fc23 @updates 9.5 M llvm x86_64 3.7.0-3.fc23 @updates 4.9 M Transaction Summary ============================================================== Remove 5 Packages When I try it again I get nice instructions on how to install it! [root@jouet ~]# perf test bpf 37: Test BPF filter : 37.1: Test basic BPF filtering : Skip 37.2: Test BPF prologue generation : Skip [root@jouet ~]# perf test -v bpf 37: Test BPF filter : 37.1: Test basic BPF filtering : --- start --- test child forked, pid 30062 ERROR: unable to find clang. Hint: Try to install latest clang/llvm to support BPF. Check your $PATH and 'clang-path' option in [llvm] section of ~/.perfconfig. LLVM 3.7 or newer is required. Which can be found from http://llvm.org You may want to try git trunk: git clone http://llvm.org/git/llvm.git and git clone http://llvm.org/git/clang.git Or fetch the latest clang/llvm 3.7 from pre-built llvm packages for debian/ubuntu: http://llvm.org/apt If you are using old version of clang, change 'clang-bpf-cmd-template' option in [llvm] section of ~/.perfconfig to: "$CLANG_EXEC $CLANG_OPTIONS $KERNEL_INC_OPTIONS \ -working-directory $WORKING_DIR -c $CLANG_SOURCE \ -emit-llvm -o - | /path/to/llc -march=bpf -filetype=obj -o -" (Replace /path/to/llc with path to your llc) Failed to compile test case: 'Basic BPF llvm compiling test' Unable to get BPF object, fix 'perf test LLVM' first test child finished with -2 ---- end ---- Test BPF filter subtest 0: Skip 37.2: Test BPF prologue generation : --- force skipped --- Test BPF filter subtest 1: Skip [root@jouet ~]# Lets try it... - Arnaldo ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 1/2] perf test: Add libbpf relocation checker 2016-01-22 15:40 ` Arnaldo Carvalho de Melo @ 2016-01-22 17:07 ` Alexei Starovoitov 2016-01-22 17:22 ` clang --target=bpf missing on f23 was: " Arnaldo Carvalho de Melo 0 siblings, 1 reply; 14+ messages in thread From: Alexei Starovoitov @ 2016-01-22 17:07 UTC (permalink / raw) To: Arnaldo Carvalho de Melo Cc: Wang Nan, ast, linux-kernel, Daniel Borkmann, Li Zefan, pi3orama 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 Targets: > aarch64 - AArch64 (little endian) > aarch64_be - AArch64 (big endian) > amdgcn - AMD GCN GPUs > arm - ARM > arm64 - ARM64 (little endian) > armeb - ARM (big endian) > cpp - C++ backend > nvptx - NVIDIA PTX 32-bit > nvptx64 - NVIDIA PTX 64-bit > ppc32 - PowerPC 32 > ppc64 - PowerPC 64 > ppc64le - PowerPC 64 LE > r600 - AMD GPUs HD2XXX-HD6XXX > systemz - SystemZ > thumb - Thumb > thumbeb - Thumb (big endian) > x86 - 32-bit X86: Pentium-Pro and above > x86-64 - 64-bit X86: EM64T and AMD64 > [root@jouet ~]# ouch, so fedorra enabled all sorts of backends, but disabled BPF?! Can somebody talk to redhat packaging folks? clang/llvm enables BPF backend by default. ^ permalink raw reply [flat|nested] 14+ messages in thread
* clang --target=bpf missing on f23 was: Re: [PATCH 1/2] perf test: Add libbpf relocation checker 2016-01-22 17:07 ` Alexei Starovoitov @ 2016-01-22 17:22 ` Arnaldo Carvalho de Melo 2016-01-22 17:35 ` Adam Jackson 0 siblings, 1 reply; 14+ messages in thread From: Arnaldo Carvalho de Melo @ 2016-01-22 17:22 UTC (permalink / raw) To: Alexei Starovoitov Cc: Wang Nan, ast, linux-kernel, Daniel Borkmann, Li Zefan, pi3orama, Dave Airlie, Adam Jackson Em Fri, Jan 22, 2016 at 09:07:50AM -0800, Alexei Starovoitov escreveu: > 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 Targets: > > aarch64 - AArch64 (little endian) > > aarch64_be - AArch64 (big endian) > > amdgcn - AMD GCN GPUs > > arm - ARM > > arm64 - ARM64 (little endian) > > armeb - ARM (big endian) > > cpp - C++ backend > > nvptx - NVIDIA PTX 32-bit > > nvptx64 - NVIDIA PTX 64-bit > > ppc32 - PowerPC 32 > > ppc64 - PowerPC 64 > > ppc64le - PowerPC 64 LE > > r600 - AMD GPUs HD2XXX-HD6XXX > > systemz - SystemZ > > thumb - Thumb > > thumbeb - Thumb (big endian) > > x86 - 32-bit X86: Pentium-Pro and above > > x86-64 - 64-bit X86: EM64T and AMD64 > > [root@jouet ~]# > > ouch, so fedora enabled all sorts of backends, but disabled BPF?! > Can somebody talk to redhat packaging folks? > clang/llvm enables BPF backend by default. Adding Adam Jackson and Dave Airlie, that last updated llvm. Hi Adam, Dave, 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(), was the decision not to include 'bpf' just an accident? BTW, this is on a recently installed Fedora 23 machine. - Arnaldo [acme@jouet linux]$ rpm -q --changelog llvm-libs | grep -v ^$ | head -20 * Thu Dec 03 2015 Stephan Bergmann <sbergman@redhat.com> 3.7.0-3 - Resolves: rhbz#1282645 add GCC abi_tag support * Thu Oct 29 2015 Adam Jackson <ajax@redhat.com> 3.7.0-2 - Drop -fno-devirtualize - Link with -static-libstdc++ to work around bundled libstdc++ in Steam * Wed Sep 16 2015 Dave Airlie <airlied@redhat.com> 3.7.0-1 - llvm 3.7.0 * Wed Jul 22 2015 Adam Jackson <ajax@redhat.com> 3.6.2-1 - llvm 3.6.2 * Wed Jun 17 2015 Dave Airlie <airlied@redhat.com> 3.6.1-1 - llvm 3.6.1 * Fri May 29 2015 Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> - 3.6.0-2 - Also require gcc-c++ at runtime (#1021645) * Thu Apr 09 2015 Adam Jackson <ajax@redhat.com> 3.6.0-1 - llvm 3.6.0 * Wed Feb 18 2015 Jonathan Wakely <jwakely@redhat.com> - 3.5.0-11 - Add patch for http://llvm.org/bugs/show_bug.cgi?id=22625 * Wed Feb 18 2015 Richard W.M. Jones <rjones@redhat.com> - 3.5.0-10 - Bump release and rebuild. * Tue Feb 17 2015 Peter Robinson <pbrobinson@fedoraproject.org> 3.5.0-9 [acme@jouet linux]$ ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: clang --target=bpf missing on f23 was: Re: [PATCH 1/2] perf test: Add libbpf relocation checker 2016-01-22 17:22 ` clang --target=bpf missing on f23 was: " Arnaldo Carvalho de Melo @ 2016-01-22 17:35 ` Adam Jackson 2016-01-22 17:42 ` Alexei Starovoitov 2016-01-22 17:56 ` Daniel Borkmann 0 siblings, 2 replies; 14+ messages in thread From: Adam Jackson @ 2016-01-22 17:35 UTC (permalink / raw) To: Arnaldo Carvalho de Melo, Alexei Starovoitov Cc: Wang Nan, ast, linux-kernel, Daniel Borkmann, Li Zefan, pi3orama, Dave Airlie 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(), was the decision not to include 'bpf' just an accident? I wouldn't call it a "decision", that would imply intent. The main reason I explicitly list targets for llvm is to limit the CPU backends to arches Fedora actually runs on (which itself is because I really only care about llvmpipe, and am only touching llvm because it's in my way). Had no idea there was a bpf backend, so never thought to enable it. llvm-3.7.0-4.fc2{3,4} are building now with the bpf backend enabled, I'll create an update for F23 when it's built. - ajax ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: clang --target=bpf missing on f23 was: Re: [PATCH 1/2] perf test: Add libbpf relocation checker 2016-01-22 17:35 ` Adam Jackson @ 2016-01-22 17:42 ` Alexei Starovoitov 2016-01-22 21:09 ` David Airlie 2016-01-22 17:56 ` Daniel Borkmann 1 sibling, 1 reply; 14+ messages in thread From: Alexei Starovoitov @ 2016-01-22 17:42 UTC (permalink / raw) To: Adam Jackson Cc: Arnaldo Carvalho de Melo, Wang Nan, ast, linux-kernel, Daniel Borkmann, Li Zefan, pi3orama, Dave Airlie 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(), was the decision not to include 'bpf' just an accident? > > I wouldn't call it a "decision", that would imply intent. The main > reason I explicitly list targets for llvm is to limit the CPU backends > to arches Fedora actually runs on (which itself is because I really > only care about llvmpipe, and am only touching llvm because it's in my > way). Had no idea there was a bpf backend, so never thought to enable > it. > > llvm-3.7.0-4.fc2{3,4} are building now with the bpf backend enabled, > I'll create an update for F23 when it's built. thanks. if you want to reduce the size of binaries, you can probably disable nvptx/amdgcn/r600, since I doubt fedora ships with appropriate sdks that can take advantage of that. ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: clang --target=bpf missing on f23 was: Re: [PATCH 1/2] perf test: Add libbpf relocation checker 2016-01-22 17:42 ` Alexei Starovoitov @ 2016-01-22 21:09 ` David Airlie 0 siblings, 0 replies; 14+ messages in thread From: David Airlie @ 2016-01-22 21:09 UTC (permalink / raw) To: Alexei Starovoitov Cc: Adam Jackson, Arnaldo Carvalho de Melo, Wang Nan, ast, linux-kernel, Daniel Borkmann, Li Zefan, pi3orama ----- Original Message ----- > From: "Alexei Starovoitov" <alexei.starovoitov@gmail.com> > To: "Adam Jackson" <ajax@redhat.com> > Cc: "Arnaldo Carvalho de Melo" <acme@kernel.org>, "Wang Nan" <wangnan0@huawei.com>, ast@kernel.org, > linux-kernel@vger.kernel.org, "Daniel Borkmann" <daniel@iogearbox.net>, "Li Zefan" <lizefan@huawei.com>, > pi3orama@163.com, "Dave Airlie" <airlied@redhat.com> > Sent: Saturday, 23 January, 2016 3:42:30 AM > Subject: 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(), was the decision not to include 'bpf' just an accident? > > > > I wouldn't call it a "decision", that would imply intent. The main > > reason I explicitly list targets for llvm is to limit the CPU backends > > to arches Fedora actually runs on (which itself is because I really > > only care about llvmpipe, and am only touching llvm because it's in my > > way). Had no idea there was a bpf backend, so never thought to enable > > it. > > > > llvm-3.7.0-4.fc2{3,4} are building now with the bpf backend enabled, > > I'll create an update for F23 when it's built. > > thanks. > if you want to reduce the size of binaries, you can probably disable > nvptx/amdgcn/r600, since I doubt fedora ships with appropriate sdks > that can take advantage of that. > amdgcn is the other reason we ship llvm, we could probably drop nvptx. Dave. > ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: clang --target=bpf missing on f23 was: Re: [PATCH 1/2] perf test: Add libbpf relocation checker 2016-01-22 17:35 ` Adam Jackson 2016-01-22 17:42 ` Alexei Starovoitov @ 2016-01-22 17:56 ` Daniel Borkmann 2016-01-22 19:09 ` Arnaldo Carvalho de Melo 1 sibling, 1 reply; 14+ messages in thread From: Daniel Borkmann @ 2016-01-22 17:56 UTC (permalink / raw) To: Adam Jackson, Arnaldo Carvalho de Melo, Alexei Starovoitov Cc: Wang Nan, ast, linux-kernel, Li Zefan, pi3orama, Dave Airlie On 01/22/2016 06:35 PM, 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(), was the decision not to include 'bpf' just an accident? > > I wouldn't call it a "decision", that would imply intent. The main > reason I explicitly list targets for llvm is to limit the CPU backends > to arches Fedora actually runs on (which itself is because I really > only care about llvmpipe, and am only touching llvm because it's in my > way). Had no idea there was a bpf backend, so never thought to enable > it. > > llvm-3.7.0-4.fc2{3,4} are building now with the bpf backend enabled, > I'll create an update for F23 when it's built. Awesome, thanks! ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: clang --target=bpf missing on f23 was: Re: [PATCH 1/2] perf test: Add libbpf relocation checker 2016-01-22 17:56 ` Daniel Borkmann @ 2016-01-22 19:09 ` Arnaldo Carvalho de Melo 0 siblings, 0 replies; 14+ messages in thread From: Arnaldo Carvalho de Melo @ 2016-01-22 19:09 UTC (permalink / raw) To: Daniel Borkmann Cc: Adam Jackson, Alexei Starovoitov, Wang Nan, ast, linux-kernel, Li Zefan, pi3orama, Dave Airlie Em Fri, Jan 22, 2016 at 06:56:02PM +0100, Daniel Borkmann escreveu: > On 01/22/2016 06:35 PM, 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(), was the decision not to include 'bpf' just an accident? > > > >I wouldn't call it a "decision", that would imply intent. The main > >reason I explicitly list targets for llvm is to limit the CPU backends > >to arches Fedora actually runs on (which itself is because I really > >only care about llvmpipe, and am only touching llvm because it's in my > >way). Had no idea there was a bpf backend, so never thought to enable > >it. > > > >llvm-3.7.0-4.fc2{3,4} are building now with the bpf backend enabled, > >I'll create an update for F23 when it's built. > > Awesome, thanks! Seconded, thanks for the fast response and for adding the bpf target! Now that is a good, intentional decision 8-) - Arnaldo ^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH 2/2] perf bpf: Check relocation target section 2016-01-22 9:27 [PATCH 0/2] perf bpf: Fix relocation error Wang Nan 2016-01-22 9:27 ` [PATCH 1/2] perf test: Add libbpf relocation checker Wang Nan @ 2016-01-22 9:27 ` Wang Nan 2016-01-22 17:11 ` Alexei Starovoitov 1 sibling, 1 reply; 14+ messages in thread From: Wang Nan @ 2016-01-22 9:27 UTC (permalink / raw) To: ast, acme Cc: linux-kernel, Wang Nan, Arnaldo Carvalho de Melo, Daniel Borkmann, Li Zefan, pi3orama Libbpf should check target section before doing relocation to ensure the relocation is correct. If not, a bug in LLVM causes error. See [1]. Also, if an incorrect BPF script uses both global variable and map, global variable whould be treated as map and be relocated without error. This patch saves id of map section into obj->efile and compare target section of a relocation symbol against it during relocation. Previous patch introduces a test case about this problem. After this patch: # ~/perf test BPF 37: Test BPF filter : 37.1: Test basic BPF filtering : Ok 37.2: Test BPF prologue generation : Ok 37.3: Test BPF relocation checker : Ok # perf test -v BPF ... 37.3: Test BPF relocation checker : ... libbpf: loading object '[bpf_relocation_test]' from buffer libbpf: section .strtab, size 126, link 0, flags 0, type=3 libbpf: section .text, size 0, link 0, flags 6, type=1 libbpf: section .data, size 0, link 0, flags 3, type=1 libbpf: section .bss, size 0, link 0, flags 3, type=8 libbpf: section func=sys_write, size 104, link 0, flags 6, type=1 libbpf: found program func=sys_write libbpf: section .relfunc=sys_write, size 16, link 10, flags 0, type=9 libbpf: section maps, size 16, link 0, flags 3, type=1 libbpf: maps in [bpf_relocation_test]: 16 bytes libbpf: section license, size 4, link 0, flags 3, type=1 libbpf: license of [bpf_relocation_test] is GPL libbpf: section version, size 4, link 0, flags 3, type=1 libbpf: kernel version of [bpf_relocation_test] is 40400 libbpf: section .symtab, size 144, link 1, flags 0, type=2 libbpf: map 0 is "my_table" libbpf: collecting relocating info for: 'func=sys_write' libbpf: Program 'func=sys_write' contains non-map related relo data pointing to section 65522 bpf: failed to load buffer Compile BPF program failed. test child finished with 0 ---- end ---- Test BPF filter subtest 2: Ok [1] https://llvm.org/bugs/show_bug.cgi?id=26243 Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Li Zefan <lizefan@huawei.com> Cc: pi3orama@163.com --- tools/lib/bpf/libbpf.c | 34 ++++++++++++++++++++++------------ 1 file changed, 22 insertions(+), 12 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 8334a5a..8fa781f 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -201,6 +201,7 @@ struct bpf_object { Elf_Data *data; } *reloc; int nr_reloc; + int maps_shndx; } efile; /* * All loaded bpf_object is linked in a list, which is @@ -350,6 +351,7 @@ static struct bpf_object *bpf_object__new(const char *path, */ obj->efile.obj_buf = obj_buf; obj->efile.obj_buf_sz = obj_buf_sz; + obj->efile.maps_shndx = -1; obj->loaded = false; @@ -529,12 +531,12 @@ bpf_object__init_maps(struct bpf_object *obj, void *data, } static int -bpf_object__init_maps_name(struct bpf_object *obj, int maps_shndx) +bpf_object__init_maps_name(struct bpf_object *obj) { int i; Elf_Data *symbols = obj->efile.symbols; - if (!symbols || maps_shndx < 0) + if (!symbols || obj->efile.maps_shndx < 0) return -EINVAL; for (i = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) { @@ -544,7 +546,7 @@ bpf_object__init_maps_name(struct bpf_object *obj, int maps_shndx) if (!gelf_getsym(symbols, i, &sym)) continue; - if (sym.st_shndx != maps_shndx) + if (sym.st_shndx != obj->efile.maps_shndx) continue; map_name = elf_strptr(obj->efile.elf, @@ -572,7 +574,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj) Elf *elf = obj->efile.elf; GElf_Ehdr *ep = &obj->efile.ehdr; Elf_Scn *scn = NULL; - int idx = 0, err = 0, maps_shndx = -1; + int idx = 0, err = 0; /* Elf is corrupted/truncated, avoid calling elf_strptr. */ if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) { @@ -625,7 +627,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj) else if (strcmp(name, "maps") == 0) { err = bpf_object__init_maps(obj, data->d_buf, data->d_size); - maps_shndx = idx; + obj->efile.maps_shndx = idx; } else if (sh.sh_type == SHT_SYMTAB) { if (obj->efile.symbols) { pr_warning("bpf: multiple SYMTAB in %s\n", @@ -674,8 +676,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj) pr_warning("Corrupted ELF file: index of strtab invalid\n"); return LIBBPF_ERRNO__FORMAT; } - if (maps_shndx >= 0) - err = bpf_object__init_maps_name(obj, maps_shndx); + if (obj->efile.maps_shndx >= 0) + err = bpf_object__init_maps_name(obj); out: return err; } @@ -697,7 +699,8 @@ bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx) static int bpf_program__collect_reloc(struct bpf_program *prog, size_t nr_maps, GElf_Shdr *shdr, - Elf_Data *data, Elf_Data *symbols) + Elf_Data *data, Elf_Data *symbols, + int maps_shndx) { int i, nrels; @@ -724,9 +727,6 @@ bpf_program__collect_reloc(struct bpf_program *prog, return -LIBBPF_ERRNO__FORMAT; } - insn_idx = rel.r_offset / sizeof(struct bpf_insn); - pr_debug("relocation: insn_idx=%u\n", insn_idx); - if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) { @@ -735,6 +735,15 @@ bpf_program__collect_reloc(struct bpf_program *prog, return -LIBBPF_ERRNO__FORMAT; } + if (sym.st_shndx != maps_shndx) { + pr_warning("Program '%s' contains non-map related relo data pointing to section %u\n", + prog->section_name, sym.st_shndx); + return -LIBBPF_ERRNO__RELOC; + } + + insn_idx = rel.r_offset / sizeof(struct bpf_insn); + pr_debug("relocation: insn_idx=%u\n", insn_idx); + if (insns[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) { pr_warning("bpf: relocation: invalid relo for insns[%d].code 0x%x\n", insn_idx, insns[insn_idx].code); @@ -863,7 +872,8 @@ static int bpf_object__collect_reloc(struct bpf_object *obj) err = bpf_program__collect_reloc(prog, nr_maps, shdr, data, - obj->efile.symbols); + obj->efile.symbols, + obj->efile.maps_shndx); if (err) return err; } -- 1.8.3.4 ^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH 2/2] perf bpf: Check relocation target section 2016-01-22 9:27 ` [PATCH 2/2] perf bpf: Check relocation target section Wang Nan @ 2016-01-22 17:11 ` Alexei Starovoitov 2016-01-25 1:56 ` Wangnan (F) 0 siblings, 1 reply; 14+ messages in thread From: Alexei Starovoitov @ 2016-01-22 17:11 UTC (permalink / raw) To: Wang Nan Cc: ast, acme, linux-kernel, Arnaldo Carvalho de Melo, Daniel Borkmann, Li Zefan, pi3orama On Fri, Jan 22, 2016 at 09:27:21AM +0000, Wang Nan wrote: > Libbpf should check target section before doing relocation to ensure > the relocation is correct. If not, a bug in LLVM causes error. See [1]. > Also, if an incorrect BPF script uses both global variable and > map, global variable whould be treated as map and be relocated > without error. > > This patch saves id of map section into obj->efile and compare > target section of a relocation symbol against it during relocation. ... > [1] https://llvm.org/bugs/show_bug.cgi?id=26243 ... > Signed-off-by: Wang Nan <wangnan0@huawei.com> > > + if (sym.st_shndx != maps_shndx) { > + pr_warning("Program '%s' contains non-map related relo data pointing to section %u\n", > + prog->section_name, sym.st_shndx); > + 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 <ast@kernel.org> ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 2/2] perf bpf: Check relocation target section 2016-01-22 17:11 ` Alexei Starovoitov @ 2016-01-25 1:56 ` Wangnan (F) 2016-01-25 2:04 ` Wangnan (F) 0 siblings, 1 reply; 14+ messages in thread From: Wangnan (F) @ 2016-01-25 1:56 UTC (permalink / raw) To: Alexei Starovoitov Cc: ast, acme, linux-kernel, Arnaldo Carvalho de Melo, Daniel Borkmann, Li Zefan, pi3orama On 2016/1/23 1:11, Alexei Starovoitov wrote: > On Fri, Jan 22, 2016 at 09:27:21AM +0000, Wang Nan wrote: >> Libbpf should check target section before doing relocation to ensure >> the relocation is correct. If not, a bug in LLVM causes error. See [1]. >> Also, if an incorrect BPF script uses both global variable and >> map, global variable whould be treated as map and be relocated >> without error. >> >> This patch saves id of map section into obj->efile and compare >> target section of a relocation symbol against it during relocation. > ... >> [1] https://llvm.org/bugs/show_bug.cgi?id=26243 > ... >> Signed-off-by: Wang Nan <wangnan0@huawei.com> >> >> + if (sym.st_shndx != maps_shndx) { >> + pr_warning("Program '%s' contains non-map related relo data pointing to section %u\n", >> + prog->section_name, sym.st_shndx); >> + return -LIBBPF_ERRNO__RELOC; >> + } > May be 'pr_err' instead of 'pr_warning', since such program will fail > to load by kernel anyway. Libbpf doesn't issue pr_error even in fatal exception because it doesn't define pr_err at all. It reports error code and let perf deal with error. Thank you. > Looks good otherwise. > Acked-by: Alexei Starovoitov <ast@kernel.org> > ^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 2/2] perf bpf: Check relocation target section 2016-01-25 1:56 ` Wangnan (F) @ 2016-01-25 2:04 ` Wangnan (F) 0 siblings, 0 replies; 14+ messages in thread From: Wangnan (F) @ 2016-01-25 2:04 UTC (permalink / raw) To: Alexei Starovoitov Cc: ast, acme, linux-kernel, Arnaldo Carvalho de Melo, Daniel Borkmann, Li Zefan, pi3orama On 2016/1/25 9:56, Wangnan (F) wrote: > > > On 2016/1/23 1:11, Alexei Starovoitov wrote: >> On Fri, Jan 22, 2016 at 09:27:21AM +0000, Wang Nan wrote: >>> Libbpf should check target section before doing relocation to ensure >>> the relocation is correct. If not, a bug in LLVM causes error. See [1]. >>> Also, if an incorrect BPF script uses both global variable and >>> map, global variable whould be treated as map and be relocated >>> without error. >>> >>> This patch saves id of map section into obj->efile and compare >>> target section of a relocation symbol against it during relocation. >> ... >>> [1] https://llvm.org/bugs/show_bug.cgi?id=26243 >> ... >>> Signed-off-by: Wang Nan <wangnan0@huawei.com> >>> + if (sym.st_shndx != maps_shndx) { >>> + pr_warning("Program '%s' contains non-map related relo >>> data pointing to section %u\n", >>> + prog->section_name, sym.st_shndx); >>> + return -LIBBPF_ERRNO__RELOC; There's a trailing whitespace. Sorry. >>> + } >> May be 'pr_err' instead of 'pr_warning', since such program will fail >> to load by kernel anyway. > > Libbpf doesn't issue pr_error even in fatal exception because it > doesn't define > pr_err at all. It reports error code and let perf deal with error. > > Thank you. > >> Looks good otherwise. >> Acked-by: Alexei Starovoitov <ast@kernel.org> >> > ^ permalink raw reply [flat|nested] 14+ messages in thread
end of thread, other threads:[~2016-01-25 2:05 UTC | newest] Thread overview: 14+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2016-01-22 9:27 [PATCH 0/2] perf bpf: Fix relocation error Wang Nan 2016-01-22 9:27 ` [PATCH 1/2] perf test: Add libbpf relocation checker Wang Nan 2016-01-22 15:40 ` Arnaldo Carvalho de Melo 2016-01-22 17:07 ` Alexei Starovoitov 2016-01-22 17:22 ` clang --target=bpf missing on f23 was: " Arnaldo Carvalho de Melo 2016-01-22 17:35 ` Adam Jackson 2016-01-22 17:42 ` Alexei Starovoitov 2016-01-22 21:09 ` David Airlie 2016-01-22 17:56 ` Daniel Borkmann 2016-01-22 19:09 ` Arnaldo Carvalho de Melo 2016-01-22 9:27 ` [PATCH 2/2] perf bpf: Check relocation target section Wang Nan 2016-01-22 17:11 ` Alexei Starovoitov 2016-01-25 1:56 ` Wangnan (F) 2016-01-25 2:04 ` Wangnan (F)
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