Messages in this thread | | | Date | Thu, 26 Jul 2018 15:58:05 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: BPF relocation 'perf test' entries failing was: Re: [GIT PULL 00/27] perf/core improvements and fixes |
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Em Thu, Jul 26, 2018 at 11:04:08PM +0530, Sandipan Das escreveu: > Hi Arnaldo, > > I came across the same problem. Does the following patch fix it? > https://lkml.org/lkml/2018/7/26/669
Oh my, that one was subtle... Checking...
- Arnaldo
> - Sandipan > > On Thursday 26 July 2018 06:45 PM, Arnaldo Carvalho de Melo wrote: > > Em Wed, Jul 25, 2018 at 02:59:34PM -0300, Arnaldo Carvalho de Melo escreveu: > >> Hi Ingo, > >> > >> Please consider pulling, I'm now investigating why these failed: > >> > >> 38: LLVM search and compile : > >> 38.1: Basic BPF llvm compile : Ok > >> 38.2: kbuild searching : Ok > >> 38.3: Compile source for BPF prologue generation : Ok > >> 38.4: Compile source for BPF relocation : FAILED! > >> 40: BPF filter : > >> 40.1: Basic BPF filtering : Ok > >> 40.2: BPF pinning : Ok > >> 40.3: BPF prologue generation : Ok > >> 40.4: BPF relocation checker : FAILED! > >> > >> I think these failures are not related to changes in this patch > >> kit. Details about the test environment, versions, etc. > > > > So, here are more details: > > > > The relevant bit seems to be: > > > > libbpf: Program 'func=sys_write' contains non-map related relo data pointing to section 65522 > > > > So this seems to be something that was caught by the kernel verifier and > > now is being caught by libbpf, /me goes to read the tools/lib/bpf > > changelog... > > > > - Arnaldo > > > > BPF filter subtest 2: Ok > > 40.3: BPF prologue generation : > > --- start --- > > test child forked, pid 13336 > > Kernel build dir is set to /lib/modules/4.18.0-rc6-00093-g9981b4fb8684/build > > set env: KBUILD_DIR=/lib/modules/4.18.0-rc6-00093-g9981b4fb8684/build > > unset env: KBUILD_OPTS > > include option is set to -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h > > set env: NR_CPUS=4 > > set env: LINUX_VERSION_CODE=0x41200 > > set env: CLANG_EXEC=/usr/lib64/ccache/clang > > set env: CLANG_OPTIONS=-xc > > set env: KERNEL_INC_OPTIONS= -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h > > set env: PERF_BPF_INC_OPTIONS=-I/home/acme/lib/include/perf/bpf > > set env: WORKING_DIR=/lib/modules/4.18.0-rc6-00093-g9981b4fb8684/build > > set env: CLANG_SOURCE=- > > llvm compiling command template: echo '/* > > * 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; > > ' | $CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS -DLINUX_VERSION_CODE=$LINUX_VERSION_CODE $CLANG_OPTIONS $KERNEL_INC_OPTIONS $PERF_BPF_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c "$CLANG_SOURCE" -target bpf -O2 -o - > > llvm compiling command : echo '/* > > * 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; > > ' | /usr/lib64/ccache/clang -D__KERNEL__ -D__NR_CPUS__=4 -DLINUX_VERSION_CODE=0x41200 -xc -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h -I/home/acme/lib/include/perf/bpf -Wno-unused-value -Wno-pointer-sign -working-directory /lib/modules/4.18.0-rc6-00093-g9981b4fb8684/build -c - -target bpf -O2 -o - > > libbpf: loading object '[bpf_relocation_test]' from buffer > > libbpf: section(1) .strtab, size 115, link 0, flags 0, type=3 > > libbpf: skip section(1) .strtab > > libbpf: section(2) .text, size 0, link 0, flags 6, type=1 > > libbpf: skip section(2) .text > > libbpf: section(3) func=sys_write, size 104, link 0, flags 6, type=1 > > libbpf: found program func=sys_write > > libbpf: section(4) .relfunc=sys_write, size 16, link 8, flags 0, type=9 > > libbpf: section(5) maps, size 16, link 0, flags 3, type=1 > > libbpf: section(6) license, size 4, link 0, flags 3, type=1 > > libbpf: license of [bpf_relocation_test] is GPL > > libbpf: section(7) version, size 4, link 0, flags 3, type=1 > > libbpf: kernel version of [bpf_relocation_test] is 41200 > > libbpf: section(8) .symtab, size 144, link 1, flags 0, type=2 > > libbpf: maps in [bpf_relocation_test]: 1 maps in 16 bytes > > libbpf: map 0 is "my_table" > > libbpf: collecting relocating info for: 'func=sys_write' > > libbpf: relo for 5 value 4 name 21 > > 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 ---- > > BPF filter subtest 3: Ok > > 40.4: BPF relocation checker : > > --- start --- > > test child forked, pid 13746 > > test child finished with -1 > > ---- end ---- > > BPF filter subtest 4: FAILED! > > [root@seventh ~]# > > > >
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