eBPF "restricted C" code can be compiled with LLVM/clang using target triplets like armv7l-unknown-linux-gnueabihf and loaded/run with small cross-compiled gobpf/elf [1] programs without requiring a full BCC port which is also undesirable on small embedded systems due to its size footprint. The only missing pieces are these helper macros which otherwise have to be redefined by each eBPF arm program.
[1] https://github.com/iovisor/gobpf/tree/master/elf
Signed-off-by: Adrian Ratiu adrian.ratiu@collabora.com --- tools/testing/selftests/bpf/bpf_helpers.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index 6c77cf7bedce..f7883576f445 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -232,6 +232,9 @@ static int (*bpf_skb_pull_data)(void *, int len) = #elif defined(__TARGET_ARCH_s930x) #define bpf_target_s930x #define bpf_target_defined +#elif defined(__TARGET_ARCH_arm) + #define bpf_target_arm + #define bpf_target_defined #elif defined(__TARGET_ARCH_arm64) #define bpf_target_arm64 #define bpf_target_defined @@ -254,6 +257,8 @@ static int (*bpf_skb_pull_data)(void *, int len) = #define bpf_target_x86 #elif defined(__s390x__) #define bpf_target_s930x +#elif defined(__arm__) + #define bpf_target_arm #elif defined(__aarch64__) #define bpf_target_arm64 #elif defined(__mips__) @@ -291,6 +296,19 @@ static int (*bpf_skb_pull_data)(void *, int len) = #define PT_REGS_SP(x) ((x)->gprs[15]) #define PT_REGS_IP(x) ((x)->psw.addr)
+#elif defined(bpf_target_arm) + +#define PT_REGS_PARM1(x) ((x)->uregs[0]) +#define PT_REGS_PARM2(x) ((x)->uregs[1]) +#define PT_REGS_PARM3(x) ((x)->uregs[2]) +#define PT_REGS_PARM4(x) ((x)->uregs[3]) +#define PT_REGS_PARM5(x) ((x)->uregs[4]) +#define PT_REGS_RET(x) ((x)->uregs[14]) +#define PT_REGS_FP(x) ((x)->uregs[11]) /* Works only with CONFIG_FRAME_POINTER */ +#define PT_REGS_RC(x) ((x)->uregs[0]) +#define PT_REGS_SP(x) ((x)->uregs[13]) +#define PT_REGS_IP(x) ((x)->uregs[12]) + #elif defined(bpf_target_arm64)
#define PT_REGS_PARM1(x) ((x)->regs[0])
On Mon, Mar 4, 2019 at 12:50 PM Adrian Ratiu adrian.ratiu@collabora.com wrote:
eBPF "restricted C" code can be compiled with LLVM/clang using target triplets like armv7l-unknown-linux-gnueabihf and loaded/run with small cross-compiled gobpf/elf [1] programs without requiring a full BCC port which is also undesirable on small embedded systems due to its size footprint. The only missing pieces are these helper macros which otherwise have to be redefined by each eBPF arm program.
[1] https://github.com/iovisor/gobpf/tree/master/elf
Signed-off-by: Adrian Ratiu adrian.ratiu@collabora.com
I think this is for bpf-next tree, which is closed during the merge window. Please resubmit when the bpf-next trees is opened (usually in 2 weeks).
Thanks, Song
tools/testing/selftests/bpf/bpf_helpers.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index 6c77cf7bedce..f7883576f445 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -232,6 +232,9 @@ static int (*bpf_skb_pull_data)(void *, int len) = #elif defined(__TARGET_ARCH_s930x) #define bpf_target_s930x #define bpf_target_defined +#elif defined(__TARGET_ARCH_arm)
#define bpf_target_arm
#define bpf_target_defined
#elif defined(__TARGET_ARCH_arm64) #define bpf_target_arm64 #define bpf_target_defined @@ -254,6 +257,8 @@ static int (*bpf_skb_pull_data)(void *, int len) = #define bpf_target_x86 #elif defined(__s390x__) #define bpf_target_s930x +#elif defined(__arm__)
#define bpf_target_arm
#elif defined(__aarch64__) #define bpf_target_arm64 #elif defined(__mips__) @@ -291,6 +296,19 @@ static int (*bpf_skb_pull_data)(void *, int len) = #define PT_REGS_SP(x) ((x)->gprs[15]) #define PT_REGS_IP(x) ((x)->psw.addr)
+#elif defined(bpf_target_arm)
+#define PT_REGS_PARM1(x) ((x)->uregs[0]) +#define PT_REGS_PARM2(x) ((x)->uregs[1]) +#define PT_REGS_PARM3(x) ((x)->uregs[2]) +#define PT_REGS_PARM4(x) ((x)->uregs[3]) +#define PT_REGS_PARM5(x) ((x)->uregs[4]) +#define PT_REGS_RET(x) ((x)->uregs[14]) +#define PT_REGS_FP(x) ((x)->uregs[11]) /* Works only with CONFIG_FRAME_POINTER */ +#define PT_REGS_RC(x) ((x)->uregs[0]) +#define PT_REGS_SP(x) ((x)->uregs[13]) +#define PT_REGS_IP(x) ((x)->uregs[12])
#elif defined(bpf_target_arm64)
#define PT_REGS_PARM1(x) ((x)->regs[0])
2.20.1
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