From nobody Fri Jun 13 19:20:14 2025 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4bJq3f5xzfz51045; Fri, 13 Jun 2025 19:20:14 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R11" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4bJq3f52kZz42q5; Fri, 13 Jun 2025 19:20:14 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1749842414; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=J2FbB8BPiZ6E1atbOFGSppV4+Wjd4ynBH4k6swxr9rU=; b=yPlqfpXHWilg6S35rqozY+RxByo6G5W3k2J8suuxQnQhyFeaVMZqw3LfKyBckUaOiWJRn3 orDUHMfuTdT3B1EJhDN9/U1+4aml6hwAdG6fwzb3KFsvLMvGsY9N0zikfL0V4WyhRQzpxM z/Rgr1uhIizglwVt5xAjGwi2QA7gg+t9oV8onHyoPU5Ngw/cjlYQrtNeRuVKiAeQnrehpf fSZ3SWE3NXdRTqyQHbcMIK8hjgx9uD21tZity6dYfjJdLqKjIWvl/drFldWWCT7xdNTFe7 66cYQH2br6V+v9qoQXtRaIz8Ahhgz1J5O8fJD4pqcBmnf0KnOuE6/CcV30ZF5g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1749842414; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=J2FbB8BPiZ6E1atbOFGSppV4+Wjd4ynBH4k6swxr9rU=; b=dGi6guYOmBzGhJUUWsmMhda+pIrpmVv/lEeyreLJkDG8C+1ay5rXI9XGJctPrbSKSftgk2 ENl7GQBGJeZhiAYmr9AgY7cGKoxghbQ7bU+UawarNGgf4ixuT6SeGLLb3vP/jKJbvqna2g WzhuhxXwaqGrqoQnU7tvqu2CryugQTDJRsKMMdRwlvNvZiefjXFpFBrXRVtKW3jirtyYBa WV+dtquZtTRrl3kqyL1sRFYwk1pa5VpG9TnO/zcso+xKCdjMiMa8GIX7wKBbMvNiVtwqYw a6YccKPoXFyvmBdS3nK2S3BlSSmiMgwkUjb0ws8Ms4khk6NjCaKmJ+K7Bj06EQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1749842414; a=rsa-sha256; cv=none; b=X9a/pKjvoQqWTISIHeqTtULI7ywf2cLfZoPfaLfGz/o1d/VRx+5sheGU9tAfRhm4Myn/zh HNm0W5lW7ZJtolBa7WmJhNih74m+LHRjtbbJZ5P9WcJBeP5g3eVfith0fs5qfBsCEQ6uJp MPwtQL9/Z+40lZLt1/XGhSvX2XG3+h6kGjjMFSodz8CFCq+R+j0IgSZC5ExdiOdLc+ds5D CcfqVQU14C86b4YPNIdwBFcIhb+qXPL3BF6o13KWTS5UO2Y2As2QntdFz+K6lz2w1f5L7s QmTp3QIFIAzwpasaUUFjwLxBAtKQDB8n2BUH3H2ZVtZavVdY/jVhrVGLUNnIoQ== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4bJq3f49X7z19GG; Fri, 13 Jun 2025 19:20:14 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 55DJKE50006187; Fri, 13 Jun 2025 19:20:14 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 55DJKEGT006179; Fri, 13 Jun 2025 19:20:14 GMT (envelope-from git) Date: Fri, 13 Jun 2025 19:20:14 GMT Message-Id: <202506131920.55DJKEGT006179@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mark Johnston Subject: git: 48a656c588f9 - main - linux: Fix usage of ptrace(PT_GET_SC_ARGS) List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: markj X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 48a656c588f9fb995b9c524b57dd5febd9f69168 Auto-Submitted: auto-generated The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=48a656c588f9fb995b9c524b57dd5febd9f69168 commit 48a656c588f9fb995b9c524b57dd5febd9f69168 Author: Mark Johnston AuthorDate: 2025-06-13 19:03:03 +0000 Commit: Mark Johnston CommitDate: 2025-06-13 19:19:59 +0000 linux: Fix usage of ptrace(PT_GET_SC_ARGS) The native handler expects the argument to be a pointer to an array of 8 syscall arguments, whereas the emulation provided an array that holds up to 6. Handle this by adding a new range of Linuxulator-specific ptrace commands. In particular, introduce PTLINUX_GET_SC_ARGS, which always copies exactly six arguments. This fixes the problem and removes the hack of checking the target thread ABI to decide whether to apply a Linux-specific quirk to PT_GET_SC_ARGS. Reviewed by: kib MFC after: 2 weeks Sponsored by: Klara, Inc. Differential Revision: https://reviews.freebsd.org/D50758 --- sys/compat/freebsd32/freebsd32_misc.c | 3 +++ sys/compat/linux/linux_ptrace.c | 18 ++++-------------- sys/kern/sys_process.c | 27 +++++++++++++++++++++------ sys/sys/ptrace.h | 8 ++++++++ 4 files changed, 36 insertions(+), 20 deletions(-) diff --git a/sys/compat/freebsd32/freebsd32_misc.c b/sys/compat/freebsd32/freebsd32_misc.c index cc777f2bf830..75fdb1f544ca 100644 --- a/sys/compat/freebsd32/freebsd32_misc.c +++ b/sys/compat/freebsd32/freebsd32_misc.c @@ -1177,6 +1177,9 @@ freebsd32_ptrace(struct thread *td, struct freebsd32_ptrace_args *uap) pscr_args[i] = pscr_args32[i]; r.sr.pscr_args = pscr_args; break; + case PTLINUX_FIRST ... PTLINUX_LAST: + error = EINVAL; + break; default: addr = uap->addr; break; diff --git a/sys/compat/linux/linux_ptrace.c b/sys/compat/linux/linux_ptrace.c index 421760eab2a9..0dbfd2177122 100644 --- a/sys/compat/linux/linux_ptrace.c +++ b/sys/compat/linux/linux_ptrace.c @@ -386,21 +386,11 @@ linux_ptrace_get_syscall_info(struct thread *td, pid_t pid, if (lwpinfo.pl_flags & PL_FLAG_SCE) { si.op = LINUX_PTRACE_SYSCALL_INFO_ENTRY; si.entry.nr = lwpinfo.pl_syscall_code; - /* - * The use of PT_GET_SC_ARGS there is special, - * implementation of PT_GET_SC_ARGS for Linux-ABI - * callers emulates Linux bug which strace(1) depends - * on: at initialization it tests whether ptrace works - * by calling close(2), or some other single-argument - * syscall, _with six arguments_, and then verifies - * whether it can fetch them all using this API; - * otherwise it bails out. - */ - error = kern_ptrace(td, PT_GET_SC_ARGS, pid, - &si.entry.args, sizeof(si.entry.args)); + error = kern_ptrace(td, PTLINUX_GET_SC_ARGS, pid, + si.entry.args, sizeof(si.entry.args)); if (error != 0) { - linux_msg(td, "PT_GET_SC_ARGS failed with error %d", - error); + linux_msg(td, + "PT_LINUX_GET_SC_ARGS failed with error %d", error); return (error); } } else if (lwpinfo.pl_flags & PL_FLAG_SCX) { diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c index 8b382cb3048e..821c537065b3 100644 --- a/sys/kern/sys_process.c +++ b/sys/kern/sys_process.c @@ -690,6 +690,9 @@ sys_ptrace(struct thread *td, struct ptrace_args *uap) break; r.sr.pscr_args = pscr_args; break; + case PTLINUX_FIRST ... PTLINUX_LAST: + error = EINVAL; + break; default: addr = uap->addr; break; @@ -1166,7 +1169,9 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data) break; case PT_GET_SC_ARGS: - CTR1(KTR_PTRACE, "PT_GET_SC_ARGS: pid %d", p->p_pid); + case PTLINUX_GET_SC_ARGS: + CTR2(KTR_PTRACE, "%s: pid %d", req == PT_GET_SC_ARGS ? + "PT_GET_SC_ARGS" : "PT_LINUX_GET_SC_ARGS", p->p_pid); if (((td2->td_dbgflags & (TDB_SCE | TDB_SCX)) == 0 && td2->td_sa.code == 0) #ifdef COMPAT_FREEBSD32 @@ -1176,11 +1181,21 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data) error = EINVAL; break; } - bzero(addr, sizeof(td2->td_sa.args)); - /* See the explanation in linux_ptrace_get_syscall_info(). */ - bcopy(td2->td_sa.args, addr, SV_PROC_ABI(td->td_proc) == - SV_ABI_LINUX ? sizeof(td2->td_sa.args) : - td2->td_sa.callp->sy_narg * sizeof(syscallarg_t)); + if (req == PT_GET_SC_ARGS) { + bzero(addr, sizeof(td2->td_sa.args)); + bcopy(td2->td_sa.args, addr, td2->td_sa.callp->sy_narg * + sizeof(syscallarg_t)); + } else { + /* + * Emulate a Linux bug which which strace(1) depends on: + * at initialization it tests whether ptrace works by + * calling close(2), or some other single-argument + * syscall, _with six arguments_, and then verifies + * whether it can fetch them all using this API; + * otherwise it bails out. + */ + bcopy(td2->td_sa.args, addr, 6 * sizeof(syscallarg_t)); + } break; case PT_GET_SC_RET: diff --git a/sys/sys/ptrace.h b/sys/sys/ptrace.h index 3a7b87bfc85f..13291cd31cf5 100644 --- a/sys/sys/ptrace.h +++ b/sys/sys/ptrace.h @@ -87,8 +87,16 @@ #define PT_SC_REMOTE 44 /* Execute a syscall */ #define PT_FIRSTMACH 64 /* for machine-specific requests */ +#define PT_LASTMACH 127 #include /* machine-specific requests, if any */ +#ifdef _KERNEL +/* Space for Linux ptrace emulation. */ +#define PTLINUX_FIRST 128 +#define PTLINUX_LAST 191 +#define PTLINUX_GET_SC_ARGS (PTLINUX_FIRST + 0) +#endif + /* Events used with PT_GET_EVENT_MASK and PT_SET_EVENT_MASK */ #define PTRACE_EXEC 0x0001 #define PTRACE_SCE 0x0002