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 ~]#
Hi Arnaldo,
I came across the same problem. Does the following patch fix it?
https://lkml.org/lkml/2018/7/26/669
- 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 ~]#
>
>
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 ~]#
> >
> >
Em Thu, Jul 26, 2018 at 03:58:05PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Thu, Jul 26, 2018 at 11:04:08PM +0530, Sandipan Das escreveu:
> > 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...
Right, when it said it was running:
40.3: BPF prologue generation
In fact it was running:
40.4: BPF relocation checker
That error message in the 'perf test -v' output:
libbpf: Program 'func=sys_write' contains non-map related relo data pointing to section 65522
Was the _expected_ one for "40.4: BPF relocation checker", then it
failed when it couldn't run the off by one "last" subtest, duh.
Thomas, this was a problem introduced by a patch from you, just for
reference, this one:
Fixes: 9ef0112442bd ("perf test: Fix subtest number when showing results")
I should have caught this by running 'perf test' before/after applying
that patch, I'll now make sure this is done before sending pull reqs
upstream.
In fact I did after, and thought, hey, some BPF related regression, I
must've updated clang/llvm and something new appeared on the radar, so I
went that direction and went nowhere, well, now I have an uptodate
llvm/clang combo to play with BTF, pahole, etc 8-)
Thanks!
- Arnaldo
On 07/26/2018 09:14 PM, Arnaldo Carvalho de Melo wrote:
> Em Thu, Jul 26, 2018 at 03:58:05PM -0300, Arnaldo Carvalho de Melo escreveu:
>> Em Thu, Jul 26, 2018 at 11:04:08PM +0530, Sandipan Das escreveu:
>>> 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...
>
> Right, when it said it was running:
>
> 40.3: BPF prologue generation
>
> In fact it was running:
>
> 40.4: BPF relocation checker
>
> That error message in the 'perf test -v' output:
>
> libbpf: Program 'func=sys_write' contains non-map related relo data pointing to section 65522
>
> Was the _expected_ one for "40.4: BPF relocation checker", then it
> failed when it couldn't run the off by one "last" subtest, duh.
>
> Thomas, this was a problem introduced by a patch from you, just for
> reference, this one:
>
> Fixes: 9ef0112442bd ("perf test: Fix subtest number when showing results")
>
> I should have caught this by running 'perf test' before/after applying
> that patch, I'll now make sure this is done before sending pull reqs
> upstream.
>
> In fact I did after, and thought, hey, some BPF related regression, I
> must've updated clang/llvm and something new appeared on the radar, so I
> went that direction and went nowhere, well, now I have an uptodate
> llvm/clang combo to play with BTF, pahole, etc 8-)
>
> Thanks!
>
> - Arnaldo
Sandipan,
thanks for fixing what I have messed up.
Arnaldo,
sorry for the hickup, I should have caught this too. In fact I ran
perf test before and after, but redirected the output and just
looked at the grep'ed lines on the screen....
I should be looked more carefully...
Apologies for the mess and thanks again for fixing this.
--
Thomas Richter, Dept 3303, IBM s390 Linux Development, Boeblingen, Germany
--
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