On Tue, Jun 12, 2018 at 05:41:26PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Tue, Jun 12, 2018 at 05:31:24PM -0300, Arnaldo Carvalho de Melo escreveu:
> > Em Thu, Jun 07, 2018 at 01:07:01PM -0700, Martin KaFai Lau escreveu:
> > > On Thu, Jun 07, 2018 at 04:30:29PM -0300, Arnaldo Carvalho de Melo wrote:
> > > > So this must be available in a newer llvm version? Which one?
> >
> > > I should have put in the details in my last email or
> > > in the commit message, my bad.
> >
> > > 1. The tools/testing/selftests/bpf/Makefile has the CLANG_FLAGS and
> > > LLC_FLAGS needed to compile the bpf prog. It requires a new
> > > "-mattr=dwarf" llc option which was added to the future
> > > llvm 7.0.
>
> > [root@jouet bpf]# pahole hello.o
> > struct clang version 5.0.1 (tags/RELEASE_501/final) {
> > clang version 5.0.1 (tags/RELEASE_501/final) clang version 5.0.1
> > (tags/RELEASE_501/final); /* 0 4 */
> > clang version 5.0.1 (tags/RELEASE_501/final) clang version 5.0.1
> > (tags/RELEASE_501/final); /* 4 4 */
> > clang version 5.0.1 (tags/RELEASE_501/final) clang version 5.0.1
> > (tags/RELEASE_501/final); /* 8 4 */
> > clang version 5.0.1 (tags/RELEASE_501/final) clang version 5.0.1
> > (tags/RELEASE_501/final); /* 12 4 */
> >
> > /* size: 16, cachelines: 1, members: 4 */
> > /* last cacheline: 16 bytes */
> > };
> > [root@jouet bpf]#
> >
> > Ok, I guess I saw this case in the llvm/clang git logs, so this one was
> > generated with the older clang, will regenerate and add that "-mattr=dwarf"
> > part.
>
> [root@jouet bpf]# pahole hello.o
> struct clang version 7.0.0
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_clang.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=_Qzsu689xEjjl9JvYCvJsIZLZZKDLB6rM-Uc0gqQvyg&e=
> 8c873daccce7ee5339b9fd82c81fe02b73543b65)
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_llvm.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=cFz6VP_YIYy_hubsx05WDqpTDyXl0Wnx_RAmAl1dbpg&e=
> 98c78e82f54be8fb0bb5f02e3ca674fbde10ef34) {
> clang version 7.0.0
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_clang.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=_Qzsu689xEjjl9JvYCvJsIZLZZKDLB6rM-Uc0gqQvyg&e=
> 8c873daccce7ee5339b9fd82c81fe02b73543b65)
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_llvm.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=cFz6VP_YIYy_hubsx05WDqpTDyXl0Wnx_RAmAl1dbpg&e=
> 98c78 clang version 7.0.0
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_clang.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=_Qzsu689xEjjl9JvYCvJsIZLZZKDLB6rM-Uc0gqQvyg&e=
> 8c873daccce7ee5339b9fd82c81fe02b73543b65)
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_llvm.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=cFz6VP_YIYy_hubsx05WDqpTDyXl0Wnx_RAmAl1dbpg&e=
> 98c78e82f54be8fb0bb5f02e3ca674fbde10ef34); /* 0 4 */
> clang version 7.0.0
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_clang.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=_Qzsu689xEjjl9JvYCvJsIZLZZKDLB6rM-Uc0gqQvyg&e=
> 8c873daccce7ee5339b9fd82c81fe02b73543b65)
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_llvm.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=cFz6VP_YIYy_hubsx05WDqpTDyXl0Wnx_RAmAl1dbpg&e=
> 98c78 clang version 7.0.0
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_clang.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=_Qzsu689xEjjl9JvYCvJsIZLZZKDLB6rM-Uc0gqQvyg&e=
> 8c873daccce7ee5339b9fd82c81fe02b73543b65)
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_llvm.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=cFz6VP_YIYy_hubsx05WDqpTDyXl0Wnx_RAmAl1dbpg&e=
> 98c78e82f54be8fb0bb5f02e3ca674fbde10ef34); /* 4 4 */
> clang version 7.0.0
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_clang.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=_Qzsu689xEjjl9JvYCvJsIZLZZKDLB6rM-Uc0gqQvyg&e=
> 8c873daccce7ee5339b9fd82c81fe02b73543b65)
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_llvm.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=cFz6VP_YIYy_hubsx05WDqpTDyXl0Wnx_RAmAl1dbpg&e=
> 98c78 clang version 7.0.0
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_clang.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=_Qzsu689xEjjl9JvYCvJsIZLZZKDLB6rM-Uc0gqQvyg&e=
> 8c873daccce7ee5339b9fd82c81fe02b73543b65)
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_llvm.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=cFz6VP_YIYy_hubsx05WDqpTDyXl0Wnx_RAmAl1dbpg&e=
> 98c78e82f54be8fb0bb5f02e3ca674fbde10ef34); /* 8 4 */
> clang version 7.0.0
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_clang.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=_Qzsu689xEjjl9JvYCvJsIZLZZKDLB6rM-Uc0gqQvyg&e=
> 8c873daccce7ee5339b9fd82c81fe02b73543b65)
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_llvm.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=cFz6VP_YIYy_hubsx05WDqpTDyXl0Wnx_RAmAl1dbpg&e=
> 98c78 clang version 7.0.0
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_clang.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=_Qzsu689xEjjl9JvYCvJsIZLZZKDLB6rM-Uc0gqQvyg&e=
> 8c873daccce7ee5339b9fd82c81fe02b73543b65)
> (https://urldefense.proofpoint.com/v2/url?u=http-3A__llvm.org_git_llvm.git&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=4d495SlcvobgBOFahId75gM-V2su4Qq2wiLOGkU-adI&s=cFz6VP_YIYy_hubsx05WDqpTDyXl0Wnx_RAmAl1dbpg&e=
> 98c78e82f54be8fb0bb5f02e3ca674fbde10ef34); /* 12 4 */
>
> /* size: 16, cachelines: 1, members: 4 */
> /* last cacheline: 16 bytes */
> };
That means the "-mattr=dwarf" is not effective.
Can you share your clang and llc command to create hello.o?
> [root@jouet bpf]#
>
> Ideas?
>
> [root@jouet bpf]# trace -e open*,hello.c
> clang-6.0: error: unknown argument: '-mattr=dwarf'
> ERROR: unable to compile hello.c
> Hint: Check error message shown above.
> Hint: You can also pre-compile it into .o using:
> clang -target bpf -O2 -c hello.c
> with proper -I and -D options.
> event syntax error: 'hello.c'
> \___ Failed to load hello.c from source: Error when
> compiling BPF scriptlet
>
> (add -v to see detail)
> Run 'perf list' for a list of valid events
>
> Usage: perf trace [<options>] [<command>]
> or: perf trace [<options>] -- <command> [<options>]
> or: perf trace record [<options>] [<command>]
> or: perf trace record [<options>] -- <command> [<options>]
>
> -e, --event <event> event/syscall selector. use 'perf list' to list
> available events
> [root@jouet bpf]#
>
> [root@jouet bpf]# trace -v -e open*,hello.c
> bpf: builtin compilation failed: -95, try external compiler
> Kernel build dir is set to /lib/modules/4.17.0-rc5/build
> set env: KBUILD_DIR=/lib/modules/4.17.0-rc5/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=0x41100
> set env: CLANG_EXEC=/usr/local/bin/clang
> set env: CLANG_OPTIONS=-g -mattr=dwarf
> 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/4.17.0-rc5/build
> set env: CLANG_SOURCE=/home/acme/bpf/hello.c
> llvm compiling command template: $CLANG_EXEC -D__KERNEL__
> -D__NR_CPUS__=$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 : /usr/local/bin/clang -D__KERNEL__ -D__NR_CPUS__=4
> -DLINUX_VERSION_CODE=0x41100 -g -mattr=dwarf -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/4.17.0-rc5/build -c /home/acme/bpf/hello.c
> -target bpf -O2 -o -
> clang-6.0: error: unknown argument: '-mattr=dwarf'
> ERROR: unable to compile hello.c
> Hint: Check error message shown above.
> Hint: You can also pre-compile it into .o using:
> clang -target bpf -O2 -c hello.c
> with proper -I and -D options.
> event syntax error: 'hello.c'
> \___ Failed to load hello.c from source: Error when
> compiling BPF scriptlet
>
