diff mbox series

[bpf-next,v1,2/2] selftests/bpf: Fix cross-compile issue for some files and a static compile issue for "-lzstd"

Message ID 20240827133959.1269178-3-yikai.lin@vivo.com (mailing list archive)
State New
Headers show
Series Enable vmtest for cross-compile arm64 on x86_64 host, and fix some related issues. | expand

Commit Message

Lin Yikai Aug. 27, 2024, 1:39 p.m. UTC 
1. Fix cross-compile issue for some files:
[Issue]
When cross-compiling bpf selftests for arm64 on x86_64 host, the following error occurs:
progs/loop2.c:20:7: error: incomplete definition of type 'struct user_pt_regs'
   20 |                 if (PT_REGS_RC(ctx) & 1)
      |                     ^~~~~~~~~~~~~~~

There are same error in files: loop1.c, loop2.c, loop3.c, loop6.c ???

[Reason]
On arm64, in file bpf_tracing.h, we use userspace's user_pt_regs,
which is defined in "linux/ptrace.h".
We include the header file by adding "-idirafter /usr/include" for "CLANG_CFLAGS".

However, during cross-compiling, "linux/ptrace.h" is based on x86_64
and has no definition of "struct user_pt_regs".

[Fix]
Thus, to fix this issue, we include the Linux source tree's header file directory.

2. Fix static compile issue for "-lzstd":
[Issue]
By running the command "LDLIBS=-static LDFLAGS=--sysroot=/aarch64-linux-gnu/libc ./vmtest.sh -s -- ./test_progs",
during static cross-compiling, an error occurs:
/aarch64-linux-gnu/bin/ld: aarch64-linux-gnu/libc/usr/lib/libelf.a(elf_compress.o): in function `__libelf_compress':
(.text+0xec): undefined reference to `ZSTD_createCCtx'
/aarch64-linux-gnu/bin/ld: (.text+0xf0): undefined reference to `ZSTD_createCCtx'
...

[Fix]
For static compile, add "LDLIBS += -lzstd".

Signed-off-by: Lin Yikai <yikai.lin@vivo.com>
---
 tools/testing/selftests/bpf/Makefile | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

Comments

Andrii Nakryiko Aug. 27, 2024, 10:49 p.m. UTC | #1 
On Tue, Aug 27, 2024 at 6:40 AM Lin Yikai <yikai.lin@vivo.com> wrote:
>
> 1. Fix cross-compile issue for some files:
> [Issue]
> When cross-compiling bpf selftests for arm64 on x86_64 host, the following error occurs:
> progs/loop2.c:20:7: error: incomplete definition of type 'struct user_pt_regs'
>    20 |                 if (PT_REGS_RC(ctx) & 1)
>       |                     ^~~~~~~~~~~~~~~
>
> There are same error in files: loop1.c, loop2.c, loop3.c, loop6.c ???
>
> [Reason]
> On arm64, in file bpf_tracing.h, we use userspace's user_pt_regs,
> which is defined in "linux/ptrace.h".
> We include the header file by adding "-idirafter /usr/include" for "CLANG_CFLAGS".
>
> However, during cross-compiling, "linux/ptrace.h" is based on x86_64
> and has no definition of "struct user_pt_regs".
>
> [Fix]
> Thus, to fix this issue, we include the Linux source tree's header file directory.
>

Hm.. Not sure that's the right fix. Note -D__TARGET_ARCH_$(SRCARCH) in
BPF_CFLAGS, that __TARGET_ARCH has to match actual target
architecture, so please check that first.

pw-bot: cr

> 2. Fix static compile issue for "-lzstd":
> [Issue]
> By running the command "LDLIBS=-static LDFLAGS=--sysroot=/aarch64-linux-gnu/libc ./vmtest.sh -s -- ./test_progs",
> during static cross-compiling, an error occurs:
> /aarch64-linux-gnu/bin/ld: aarch64-linux-gnu/libc/usr/lib/libelf.a(elf_compress.o): in function `__libelf_compress':
> (.text+0xec): undefined reference to `ZSTD_createCCtx'
> /aarch64-linux-gnu/bin/ld: (.text+0xf0): undefined reference to `ZSTD_createCCtx'
> ...
>
> [Fix]
> For static compile, add "LDLIBS += -lzstd".

we can probably just add it unconditionally, no? But please send it as
a separate change in its own patch

>
> Signed-off-by: Lin Yikai <yikai.lin@vivo.com>
> ---
>  tools/testing/selftests/bpf/Makefile | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index ec7d425c4022..5b725bc890d2 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -48,6 +48,10 @@ CFLAGS += -g $(OPT_FLAGS) -rdynamic                                  \
>  LDFLAGS += $(SAN_LDFLAGS)
>  LDLIBS += $(LIBELF_LIBS) -lz -lrt -lpthread
>
> +ifneq (,$(findstring -static,$(LDLIBS)))
> +LDLIBS += -lzstd
> +endif
> +
>  LDLIBS += $(shell $(PKG_CONFIG) --libs libpcap 2>/dev/null)
>  CFLAGS += $(shell $(PKG_CONFIG) --cflags libpcap 2>/dev/null)
>  CFLAGS += $(shell $(PKG_CONFIG) --exists libpcap 2>/dev/null && echo "-DTRAFFIC_MONITOR=1")
> @@ -443,13 +447,19 @@ CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
>  endif
>
>  CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
> +CLANG_CFLAGS = $(CLANG_SYS_INCLUDES)
> +
>  BPF_CFLAGS = -g -Wall -Werror -D__TARGET_ARCH_$(SRCARCH) $(MENDIAN)    \
>              -I$(INCLUDE_DIR) -I$(CURDIR) -I$(APIDIR)                   \
>              -I$(abspath $(OUTPUT)/../usr/include)                      \
>              -Wno-compare-distinct-pointer-types
>  # TODO: enable me -Wsign-compare
>
> -CLANG_CFLAGS = $(CLANG_SYS_INCLUDES)
> +#"make headers_install" at first
> +ifneq ($(CROSS_COMPILE),)
> +src_uapi_dir := $(srctree)/usr/include
> +BPF_CFLAGS += -I$(src_uapi_dir)
> +endif
>
>  $(OUTPUT)/test_l4lb_noinline.o: BPF_CFLAGS += -fno-inline
>  $(OUTPUT)/test_xdp_noinline.o: BPF_CFLAGS += -fno-inline
> --
> 2.34.1
>
Lin Yikai Aug. 28, 2024, 9:54 a.m. UTC | #2 
On 2024/8/28 06:49:18, Lin Yikai reply:

> [Some people who received this message don't often get email from andrii.nakryiko@gmail.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
> 
> On Tue, Aug 27, 2024 at 6:40 AM Lin Yikai <yikai.lin@vivo.com> wrote:
>>
>> 1. Fix cross-compile issue for some files:
>> [Issue]
>> When cross-compiling bpf selftests for arm64 on x86_64 host, the following error occurs:
>> progs/loop2.c:20:7: error: incomplete definition of type 'struct user_pt_regs'
>>     20 |                 if (PT_REGS_RC(ctx) & 1)
>>        |                     ^~~~~~~~~~~~~~~
>>
>> There are same error in files: loop1.c, loop2.c, loop3.c, loop6.c ???
>>
>> [Reason]
>> On arm64, in file bpf_tracing.h, we use userspace's user_pt_regs,
>> which is defined in "linux/ptrace.h".
>> We include the header file by adding "-idirafter /usr/include" for "CLANG_CFLAGS".
>>
>> However, during cross-compiling, "linux/ptrace.h" is based on x86_64
>> and has no definition of "struct user_pt_regs".
>>
>> [Fix]
>> Thus, to fix this issue, we include the Linux source tree's header file directory.
>>
> 
> Hm.. Not sure that's the right fix. Note -D__TARGET_ARCH_$(SRCARCH) in
> BPF_CFLAGS, that __TARGET_ARCH has to match actual target
> architecture, so please check that first.
> 

Hi, Andrii, thanks for your advice.

After searching, I find needed "user_pt_regs" is defined as below:
   bpf-next$ find ./ -name "ptrace.h" | xargs grep -rni "user_pt_regs"
   ./arch/arm64/include/uapi/asm/ptrace.h:88:struct user_pt_regs {

So we can directly add it into include directory
by below approach without "make header_install".

   +ifneq ($(CROSS_COMPILE),)
   +src_uapi_dir := $(srctree)/arch/$(SRCARCH)/include/uapi
   +BPF_CFLAGS += -I$(src_uapi_dir)
   +endif

I'll test it and send a v2 patch.

> pw-bot: cr
> 
>> 2. Fix static compile issue for "-lzstd":
>> [Issue]
>> By running the command "LDLIBS=-static LDFLAGS=--sysroot=/aarch64-linux-gnu/libc ./vmtest.sh -s -- ./test_progs",
>> during static cross-compiling, an error occurs:
>> /aarch64-linux-gnu/bin/ld: aarch64-linux-gnu/libc/usr/lib/libelf.a(elf_compress.o): in function `__libelf_compress':
>> (.text+0xec): undefined reference to `ZSTD_createCCtx'
>> /aarch64-linux-gnu/bin/ld: (.text+0xf0): undefined reference to `ZSTD_createCCtx'
>> ...
>>
>> [Fix]
>> For static compile, add "LDLIBS += -lzstd".
> 
> we can probably just add it unconditionally, no? But please send it as
> a separate change in its own patch
> 
Thanks, I'll try it for v2 patch.

>>
>> Signed-off-by: Lin Yikai <yikai.lin@vivo.com>
>> ---
>>   tools/testing/selftests/bpf/Makefile | 12 +++++++++++-
>>   1 file changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
>> index ec7d425c4022..5b725bc890d2 100644
>> --- a/tools/testing/selftests/bpf/Makefile
>> +++ b/tools/testing/selftests/bpf/Makefile
>> @@ -48,6 +48,10 @@ CFLAGS += -g $(OPT_FLAGS) -rdynamic                                  \
>>   LDFLAGS += $(SAN_LDFLAGS)
>>   LDLIBS += $(LIBELF_LIBS) -lz -lrt -lpthread
>>
>> +ifneq (,$(findstring -static,$(LDLIBS)))
>> +LDLIBS += -lzstd
>> +endif
>> +
>>   LDLIBS += $(shell $(PKG_CONFIG) --libs libpcap 2>/dev/null)
>>   CFLAGS += $(shell $(PKG_CONFIG) --cflags libpcap 2>/dev/null)
>>   CFLAGS += $(shell $(PKG_CONFIG) --exists libpcap 2>/dev/null && echo "-DTRAFFIC_MONITOR=1")
>> @@ -443,13 +447,19 @@ CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
>>   endif
>>
>>   CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
>> +CLANG_CFLAGS = $(CLANG_SYS_INCLUDES)
>> +
>>   BPF_CFLAGS = -g -Wall -Werror -D__TARGET_ARCH_$(SRCARCH) $(MENDIAN)    \
>>               -I$(INCLUDE_DIR) -I$(CURDIR) -I$(APIDIR)                   \
>>               -I$(abspath $(OUTPUT)/../usr/include)                      \
>>               -Wno-compare-distinct-pointer-types
>>   # TODO: enable me -Wsign-compare
>>
>> -CLANG_CFLAGS = $(CLANG_SYS_INCLUDES)
>> +#"make headers_install" at first
>> +ifneq ($(CROSS_COMPILE),)
>> +src_uapi_dir := $(srctree)/usr/include
>> +BPF_CFLAGS += -I$(src_uapi_dir)
>> +endif
>>
>>   $(OUTPUT)/test_l4lb_noinline.o: BPF_CFLAGS += -fno-inline
>>   $(OUTPUT)/test_xdp_noinline.o: BPF_CFLAGS += -fno-inline
>> --
>> 2.34.1
>>
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index ec7d425c4022..5b725bc890d2 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -48,6 +48,10 @@  CFLAGS += -g $(OPT_FLAGS) -rdynamic					\
 LDFLAGS += $(SAN_LDFLAGS)
 LDLIBS += $(LIBELF_LIBS) -lz -lrt -lpthread
 
+ifneq (,$(findstring -static,$(LDLIBS)))
+LDLIBS += -lzstd
+endif
+
 LDLIBS += $(shell $(PKG_CONFIG) --libs libpcap 2>/dev/null)
 CFLAGS += $(shell $(PKG_CONFIG) --cflags libpcap 2>/dev/null)
 CFLAGS += $(shell $(PKG_CONFIG) --exists libpcap 2>/dev/null && echo "-DTRAFFIC_MONITOR=1")
@@ -443,13 +447,19 @@  CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
 endif
 
 CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
+CLANG_CFLAGS = $(CLANG_SYS_INCLUDES)
+
 BPF_CFLAGS = -g -Wall -Werror -D__TARGET_ARCH_$(SRCARCH) $(MENDIAN)	\
 	     -I$(INCLUDE_DIR) -I$(CURDIR) -I$(APIDIR)			\
 	     -I$(abspath $(OUTPUT)/../usr/include)			\
 	     -Wno-compare-distinct-pointer-types
 # TODO: enable me -Wsign-compare
 
-CLANG_CFLAGS = $(CLANG_SYS_INCLUDES)
+#"make headers_install" at first
+ifneq ($(CROSS_COMPILE),)
+src_uapi_dir := $(srctree)/usr/include
+BPF_CFLAGS += -I$(src_uapi_dir)
+endif
 
 $(OUTPUT)/test_l4lb_noinline.o: BPF_CFLAGS += -fno-inline
 $(OUTPUT)/test_xdp_noinline.o: BPF_CFLAGS += -fno-inline