From 7cd04535abc95c50ba9bfa48efc76274b63c70f5 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Thu, 11 Jul 2019 16:29:29 +0200 Subject: [PATCH] selftests/bpf: make PT_REGS_* work in userspace Right now, on certain architectures, these macros are usable only with kernel headers. This patch makes it possible to use them with userspace headers and, as a consequence, not only in BPF samples, but also in BPF selftests. On s390, provide the forward declaration of struct pt_regs and cast it to user_pt_regs in PT_REGS_* macros. This is necessary, because instead of the full struct pt_regs, s390 exposes only its first member user_pt_regs to userspace, and bpf_helpers.h is used with both userspace (in selftests) and kernel (in samples) headers. It was added in commit 466698e654e8 ("s390/bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program type"). Ditto on arm64. On x86, provide userspace versions of PT_REGS_* macros. Unlike s390 and arm64, x86 provides struct pt_regs to both userspace and kernel, however, with different member names. Signed-off-by: Ilya Leoshkevich Acked-by: Andrii Nakryiko Reviewed-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/bpf_helpers.h | 75 ++++++++++++++++++++++--------- 1 file changed, 55 insertions(+), 20 deletions(-) diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index f6e3768..f804f21 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -358,6 +358,7 @@ static int (*bpf_skb_adjust_room)(void *ctx, __s32 len_diff, __u32 mode, #if defined(bpf_target_x86) +#ifdef __KERNEL__ #define PT_REGS_PARM1(x) ((x)->di) #define PT_REGS_PARM2(x) ((x)->si) #define PT_REGS_PARM3(x) ((x)->dx) @@ -368,19 +369,49 @@ static int (*bpf_skb_adjust_room)(void *ctx, __s32 len_diff, __u32 mode, #define PT_REGS_RC(x) ((x)->ax) #define PT_REGS_SP(x) ((x)->sp) #define PT_REGS_IP(x) ((x)->ip) +#else +#ifdef __i386__ +/* i386 kernel is built with -mregparm=3 */ +#define PT_REGS_PARM1(x) ((x)->eax) +#define PT_REGS_PARM2(x) ((x)->edx) +#define PT_REGS_PARM3(x) ((x)->ecx) +#define PT_REGS_PARM4(x) 0 +#define PT_REGS_PARM5(x) 0 +#define PT_REGS_RET(x) ((x)->esp) +#define PT_REGS_FP(x) ((x)->ebp) +#define PT_REGS_RC(x) ((x)->eax) +#define PT_REGS_SP(x) ((x)->esp) +#define PT_REGS_IP(x) ((x)->eip) +#else +#define PT_REGS_PARM1(x) ((x)->rdi) +#define PT_REGS_PARM2(x) ((x)->rsi) +#define PT_REGS_PARM3(x) ((x)->rdx) +#define PT_REGS_PARM4(x) ((x)->rcx) +#define PT_REGS_PARM5(x) ((x)->r8) +#define PT_REGS_RET(x) ((x)->rsp) +#define PT_REGS_FP(x) ((x)->rbp) +#define PT_REGS_RC(x) ((x)->rax) +#define PT_REGS_SP(x) ((x)->rsp) +#define PT_REGS_IP(x) ((x)->rip) +#endif +#endif #elif defined(bpf_target_s390) -#define PT_REGS_PARM1(x) ((x)->gprs[2]) -#define PT_REGS_PARM2(x) ((x)->gprs[3]) -#define PT_REGS_PARM3(x) ((x)->gprs[4]) -#define PT_REGS_PARM4(x) ((x)->gprs[5]) -#define PT_REGS_PARM5(x) ((x)->gprs[6]) -#define PT_REGS_RET(x) ((x)->gprs[14]) -#define PT_REGS_FP(x) ((x)->gprs[11]) /* Works only with CONFIG_FRAME_POINTER */ -#define PT_REGS_RC(x) ((x)->gprs[2]) -#define PT_REGS_SP(x) ((x)->gprs[15]) -#define PT_REGS_IP(x) ((x)->psw.addr) +/* s390 provides user_pt_regs instead of struct pt_regs to userspace */ +struct pt_regs; +#define PT_REGS_S390 const volatile user_pt_regs +#define PT_REGS_PARM1(x) (((PT_REGS_S390 *)(x))->gprs[2]) +#define PT_REGS_PARM2(x) (((PT_REGS_S390 *)(x))->gprs[3]) +#define PT_REGS_PARM3(x) (((PT_REGS_S390 *)(x))->gprs[4]) +#define PT_REGS_PARM4(x) (((PT_REGS_S390 *)(x))->gprs[5]) +#define PT_REGS_PARM5(x) (((PT_REGS_S390 *)(x))->gprs[6]) +#define PT_REGS_RET(x) (((PT_REGS_S390 *)(x))->gprs[14]) +/* Works only with CONFIG_FRAME_POINTER */ +#define PT_REGS_FP(x) (((PT_REGS_S390 *)(x))->gprs[11]) +#define PT_REGS_RC(x) (((PT_REGS_S390 *)(x))->gprs[2]) +#define PT_REGS_SP(x) (((PT_REGS_S390 *)(x))->gprs[15]) +#define PT_REGS_IP(x) (((PT_REGS_S390 *)(x))->psw.addr) #elif defined(bpf_target_arm) @@ -397,16 +428,20 @@ static int (*bpf_skb_adjust_room)(void *ctx, __s32 len_diff, __u32 mode, #elif defined(bpf_target_arm64) -#define PT_REGS_PARM1(x) ((x)->regs[0]) -#define PT_REGS_PARM2(x) ((x)->regs[1]) -#define PT_REGS_PARM3(x) ((x)->regs[2]) -#define PT_REGS_PARM4(x) ((x)->regs[3]) -#define PT_REGS_PARM5(x) ((x)->regs[4]) -#define PT_REGS_RET(x) ((x)->regs[30]) -#define PT_REGS_FP(x) ((x)->regs[29]) /* Works only with CONFIG_FRAME_POINTER */ -#define PT_REGS_RC(x) ((x)->regs[0]) -#define PT_REGS_SP(x) ((x)->sp) -#define PT_REGS_IP(x) ((x)->pc) +/* arm64 provides struct user_pt_regs instead of struct pt_regs to userspace */ +struct pt_regs; +#define PT_REGS_ARM64 const volatile struct user_pt_regs +#define PT_REGS_PARM1(x) (((PT_REGS_ARM64 *)(x))->regs[0]) +#define PT_REGS_PARM2(x) (((PT_REGS_ARM64 *)(x))->regs[1]) +#define PT_REGS_PARM3(x) (((PT_REGS_ARM64 *)(x))->regs[2]) +#define PT_REGS_PARM4(x) (((PT_REGS_ARM64 *)(x))->regs[3]) +#define PT_REGS_PARM5(x) (((PT_REGS_ARM64 *)(x))->regs[4]) +#define PT_REGS_RET(x) (((PT_REGS_ARM64 *)(x))->regs[30]) +/* Works only with CONFIG_FRAME_POINTER */ +#define PT_REGS_FP(x) (((PT_REGS_ARM64 *)(x))->regs[29]) +#define PT_REGS_RC(x) (((PT_REGS_ARM64 *)(x))->regs[0]) +#define PT_REGS_SP(x) (((PT_REGS_ARM64 *)(x))->sp) +#define PT_REGS_IP(x) (((PT_REGS_ARM64 *)(x))->pc) #elif defined(bpf_target_mips) -- 2.7.4