From owner-dev-commits-src-main@freebsd.org Wed Feb 17 16:08:18 2021 Return-Path: Delivered-To: dev-commits-src-main@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 4FC3C54853F; Wed, 17 Feb 2021 16:08:18 +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 "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4DgjS21sLKz3lm2; Wed, 17 Feb 2021 16:08:18 +0000 (UTC) (envelope-from git@FreeBSD.org) 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 2852327679; Wed, 17 Feb 2021 16:08:18 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 11HG8IC9000957; Wed, 17 Feb 2021 16:08:18 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 11HG8Ivs000956; Wed, 17 Feb 2021 16:08:18 GMT (envelope-from git) Date: Wed, 17 Feb 2021 16:08:18 GMT Message-Id: <202102171608.11HG8Ivs000956@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mitchell Horne Subject: git: bd012c715923 - main - arm64: handle watchpoint exceptions from EL0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: mhorne X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: bd012c71592323d957b409bb5e0cf7940729650e Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-main@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for the main branch of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 Feb 2021 16:08:18 -0000 The branch main has been updated by mhorne: URL: https://cgit.FreeBSD.org/src/commit/?id=bd012c71592323d957b409bb5e0cf7940729650e commit bd012c71592323d957b409bb5e0cf7940729650e Author: Mitchell Horne AuthorDate: 2021-02-05 21:46:48 +0000 Commit: Mitchell Horne CommitDate: 2021-02-17 16:05:00 +0000 arm64: handle watchpoint exceptions from EL0 This is a prerequisite to allowing the use of hardware watchpoints for userspace debuggers. This is also a slight departure from the x86 behaviour, since `si_addr` returns the data address that triggered the watchpoint, not the address of the instruction that was executed. Otherwise, there is no straightforward way for the application to determine which watchpoint was triggered. Make a note of this in the siginfo(3) man page. Reviewed by: jhb, markj (earlier version) Tested by: Michał Górny (mgorny@gentoo.org) MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D28561 --- share/man/man3/siginfo.3 | 7 ++++++- sys/arm64/arm64/trap.c | 6 ++++++ sys/arm64/include/armreg.h | 1 + 3 files changed, 13 insertions(+), 1 deletion(-) diff --git a/share/man/man3/siginfo.3 b/share/man/man3/siginfo.3 index fc4ea2ba1df7..acc8785b2f0d 100644 --- a/share/man/man3/siginfo.3 +++ b/share/man/man3/siginfo.3 @@ -27,7 +27,7 @@ .\" .\" $FreeBSD$ .\" -.Dd July 28, 2020 +.Dd February 17, 2021 .Dt SIGINFO 3 .Os .Sh NAME @@ -218,6 +218,11 @@ and may report the address of the faulting memory access (if available) in .Va si_addr instead. +Additionally +.Dv SIGTRAP +raised by a hardware watchpoint exception may report the data address that +triggered the watchpoint in +.Va si_addr . .Pp Sychronous signals set .Va si_trapno diff --git a/sys/arm64/arm64/trap.c b/sys/arm64/arm64/trap.c index 0b2d4760cea3..cb3a05ad0163 100644 --- a/sys/arm64/arm64/trap.c +++ b/sys/arm64/arm64/trap.c @@ -474,6 +474,7 @@ do_el0_sync(struct thread *td, struct trapframe *frame) case EXCP_UNKNOWN: case EXCP_DATA_ABORT_L: case EXCP_DATA_ABORT: + case EXCP_WATCHPT_EL0: far = READ_SPECIALREG(far_el1); break; } @@ -534,6 +535,11 @@ do_el0_sync(struct thread *td, struct trapframe *frame) exception); userret(td, frame); break; + case EXCP_WATCHPT_EL0: + call_trapsignal(td, SIGTRAP, TRAP_TRACE, (void *)far, + exception); + userret(td, frame); + break; case EXCP_MSR: /* * The CPU can raise EXCP_MSR when userspace executes an mrs diff --git a/sys/arm64/include/armreg.h b/sys/arm64/include/armreg.h index f2bce02782ec..70390d4ebf1e 100644 --- a/sys/arm64/include/armreg.h +++ b/sys/arm64/include/armreg.h @@ -230,6 +230,7 @@ #define EXCP_BRKPT_EL0 0x30 /* Hardware breakpoint, from same EL */ #define EXCP_SOFTSTP_EL0 0x32 /* Software Step, from lower EL */ #define EXCP_SOFTSTP_EL1 0x33 /* Software Step, from same EL */ +#define EXCP_WATCHPT_EL0 0x34 /* Watchpoint, from lower EL */ #define EXCP_WATCHPT_EL1 0x35 /* Watchpoint, from same EL */ #define EXCP_BRK 0x3c /* Breakpoint */