Messages in this thread | | | Date | Thu, 26 Jul 2018 10:15:34 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | BPF relocation 'perf test' entries failing was: Re: [GIT PULL 00/27] perf/core improvements and fixes |
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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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