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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
466698e654 ("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 <iii@linux.ibm.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Ilya Leoshkevich 2019-07-11 16:29:29 +02:00 committed by Daniel Borkmann
parent 05c2dc17da
commit 7cd04535ab
1 changed files with 55 additions and 20 deletions
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75
tools/testing/selftests/bpf/bpf_helpers.h
View File

@ -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)