From: Ilya Leoshkevich iii@linux.ibm.com
[ Upstream commit 1f22a6f9f9a0f50218a11a0554709fd34a821fa3 ]
On s390, the first syscall argument should be accessed via orig_gpr2 (see arch/s390/include/asm/syscall.h). Currently gpr[2] is used instead, leading to bpf_syscall_macro test failure.
orig_gpr2 cannot be added to user_pt_regs, since its layout is a part of the ABI. Therefore provide access to it only through PT_REGS_PARM1_CORE_SYSCALL() by using a struct pt_regs flavor.
Reported-by: Andrii Nakryiko andrii@kernel.org Signed-off-by: Ilya Leoshkevich iii@linux.ibm.com Signed-off-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20220209021745.2215452-11-iii@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/lib/bpf/bpf_tracing.h | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h index ad62c17919cf..92bf90e716ea 100644 --- a/tools/lib/bpf/bpf_tracing.h +++ b/tools/lib/bpf/bpf_tracing.h @@ -112,6 +112,10 @@
#elif defined(bpf_target_s390)
+struct pt_regs___s390 { + unsigned long orig_gpr2; +}; + /* s390 provides user_pt_regs instead of struct pt_regs to userspace */ #define __PT_REGS_CAST(x) ((const user_pt_regs *)(x)) #define __PT_PARM1_REG gprs[2] @@ -124,6 +128,8 @@ #define __PT_RC_REG gprs[2] #define __PT_SP_REG gprs[15] #define __PT_IP_REG psw.addr +#define PT_REGS_PARM1_SYSCALL(x) ({ _Pragma("GCC error "use PT_REGS_PARM1_CORE_SYSCALL() instead""); 0l; }) +#define PT_REGS_PARM1_CORE_SYSCALL(x) BPF_CORE_READ((const struct pt_regs___s390 *)(x), orig_gpr2)
#elif defined(bpf_target_arm)