Author: trasz Date: Tue May 14 20:59:44 2019 New Revision: 347580 URL: https://svnweb.freebsd.org/changeset/base/347580
Log: Fix handling of r10 in Linux ptrace(2). This fixes decoding of the 'flags' argument to mmap(2) with Linux strace(1). Reviewed by: dchagin MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D20223 Modified: head/sys/amd64/linux/linux_ptrace.c Modified: head/sys/amd64/linux/linux_ptrace.c ============================================================================== --- head/sys/amd64/linux/linux_ptrace.c Tue May 14 20:41:24 2019 (r347579) +++ head/sys/amd64/linux/linux_ptrace.c Tue May 14 20:59:44 2019 (r347580) @@ -338,18 +338,27 @@ linux_ptrace_getregs(struct thread *td, pid_t pid, voi map_regs_to_linux(&b_reg, &l_reg); - /* - * The strace(1) utility depends on RAX being set to -ENOSYS - * on syscall entry. - */ error = kern_ptrace(td, PT_LWPINFO, pid, &lwpinfo, sizeof(lwpinfo)); if (error != 0) { printf("%s: PT_LWPINFO failed with error %d\n", __func__, error); return (error); } - if (lwpinfo.pl_flags & PL_FLAG_SCE) - l_reg.rax = -38; // XXX: Don't hardcode? + if (lwpinfo.pl_flags & PL_FLAG_SCE) { + /* + * The strace(1) utility depends on RAX being set to -ENOSYS + * on syscall entry; otherwise it loops printing those: + * + * [ Process PID=928 runs in 64 bit mode. ] + * [ Process PID=928 runs in x32 mode. ] + */ + l_reg.rax = -38; /* -ENOSYS */ + /* + * Undo the mangling done in exception.S:fast_syscall_common(). + */ + l_reg.r10 = l_reg.rcx; + } + error = copyout(&l_reg, (void *)data, sizeof(l_reg)); return (error); } @@ -399,21 +408,27 @@ linux_ptrace_getregset_prstatus(struct thread *td, pid map_regs_to_linux_regset(&b_reg, fsbase, gsbase, &l_regset); - /* - * The strace(1) utility depends on RAX being set to -ENOSYS - * on syscall entry; otherwise it loops printing those: - * - * [ Process PID=928 runs in 64 bit mode. ] - * [ Process PID=928 runs in x32 mode. ] - */ error = kern_ptrace(td, PT_LWPINFO, pid, &lwpinfo, sizeof(lwpinfo)); if (error != 0) { printf("%s: PT_LWPINFO failed with error %d\n", __func__, error); return (error); } - if (lwpinfo.pl_flags & PL_FLAG_SCE) - l_regset.rax = -38; // XXX: Don't hardcode? + if (lwpinfo.pl_flags & PL_FLAG_SCE) { + /* + * The strace(1) utility depends on RAX being set to -ENOSYS + * on syscall entry; otherwise it loops printing those: + * + * [ Process PID=928 runs in 64 bit mode. ] + * [ Process PID=928 runs in x32 mode. ] + */ + l_regset.rax = -38; /* -ENOSYS */ + + /* + * Undo the mangling done in exception.S:fast_syscall_common(). + */ + l_regset.r10 = l_regset.rcx; + } len = MIN(iov.iov_len, sizeof(l_regset)); error = copyout(&l_regset, (void *)iov.iov_base, len); _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
