From owner-svn-src-all@freebsd.org Tue Jul 21 23:22:24 2015 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C17DC9A7AC3; Tue, 21 Jul 2015 23:22:24 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 9E0E01CED; Tue, 21 Jul 2015 23:22:24 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.70]) by repo.freebsd.org (8.14.9/8.14.9) with ESMTP id t6LNMOTC011255; Tue, 21 Jul 2015 23:22:24 GMT (envelope-from markj@FreeBSD.org) Received: (from markj@localhost) by repo.freebsd.org (8.14.9/8.14.9/Submit) id t6LNMOLb011251; Tue, 21 Jul 2015 23:22:24 GMT (envelope-from markj@FreeBSD.org) Message-Id: <201507212322.t6LNMOLb011251@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: markj set sender to markj@FreeBSD.org using -f From: Mark Johnston Date: Tue, 21 Jul 2015 23:22:24 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r285776 - in head/sys: amd64/amd64 i386/i386 X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 21 Jul 2015 23:22:24 -0000 Author: markj Date: Tue Jul 21 23:22:23 2015 New Revision: 285776 URL: https://svnweb.freebsd.org/changeset/base/285776 Log: Let the unwinder handle faults during function prologues or epilogues. The i386 and amd64 DDB stack unwinders contain code to detect and handle the case where the first frame is not completely set up or torn down. This code was accidentally unused however, since db_backtrace() was never called with a non-NULL trap frame. This change fixes that. Also remove get_rsp() from the amd64 code. It appears to have come from i386, which needs to take into account whether the exception triggered a CPL switch, since SS:ESP is only pushed onto the stack if so. On amd64, SS:RSP is pushed regardless, so get_rsp() was doing the wrong thing for kernel-mode exceptions. As a result, we can also remove custom print functions for these registers. Reviewed by: jhb Sponsored by: EMC / Isilon Storage Division Differential Revision: https://reviews.freebsd.org/D2881 Modified: head/sys/amd64/amd64/db_trace.c head/sys/i386/i386/db_trace.c Modified: head/sys/amd64/amd64/db_trace.c ============================================================================== --- head/sys/amd64/amd64/db_trace.c Tue Jul 21 23:13:11 2015 (r285775) +++ head/sys/amd64/amd64/db_trace.c Tue Jul 21 23:22:23 2015 (r285776) @@ -61,8 +61,6 @@ static db_varfcn_t db_dr5; static db_varfcn_t db_dr6; static db_varfcn_t db_dr7; static db_varfcn_t db_frame; -static db_varfcn_t db_rsp; -static db_varfcn_t db_ss; CTASSERT(sizeof(struct dbreg) == sizeof(((struct pcpu *)NULL)->pc_dbreg)); @@ -76,12 +74,12 @@ struct db_variable db_regs[] = { { "es", DB_OFFSET(tf_es), db_frame }, { "fs", DB_OFFSET(tf_fs), db_frame }, { "gs", DB_OFFSET(tf_gs), db_frame }, - { "ss", NULL, db_ss }, + { "ss", DB_OFFSET(tf_ss), db_frame }, { "rax", DB_OFFSET(tf_rax), db_frame }, { "rcx", DB_OFFSET(tf_rcx), db_frame }, { "rdx", DB_OFFSET(tf_rdx), db_frame }, { "rbx", DB_OFFSET(tf_rbx), db_frame }, - { "rsp", NULL, db_rsp }, + { "rsp", DB_OFFSET(tf_rsp), db_frame }, { "rbp", DB_OFFSET(tf_rbp), db_frame }, { "rsi", DB_OFFSET(tf_rsi), db_frame }, { "rdi", DB_OFFSET(tf_rdi), db_frame }, @@ -130,13 +128,6 @@ DB_DRX_FUNC(dr5) DB_DRX_FUNC(dr6) DB_DRX_FUNC(dr7) -static __inline long -get_rsp(struct trapframe *tf) -{ - return ((ISPL(tf->tf_cs)) ? tf->tf_rsp : - (db_expr_t)tf + offsetof(struct trapframe, tf_rsp)); -} - static int db_frame(struct db_variable *vp, db_expr_t *valuep, int op) { @@ -153,34 +144,6 @@ db_frame(struct db_variable *vp, db_expr return (1); } -static int -db_rsp(struct db_variable *vp, db_expr_t *valuep, int op) -{ - - if (kdb_frame == NULL) - return (0); - - if (op == DB_VAR_GET) - *valuep = get_rsp(kdb_frame); - else if (ISPL(kdb_frame->tf_cs)) - kdb_frame->tf_rsp = *valuep; - return (1); -} - -static int -db_ss(struct db_variable *vp, db_expr_t *valuep, int op) -{ - - if (kdb_frame == NULL) - return (0); - - if (op == DB_VAR_GET) - *valuep = (ISPL(kdb_frame->tf_cs)) ? kdb_frame->tf_ss : rss(); - else if (ISPL(kdb_frame->tf_cs)) - kdb_frame->tf_ss = *valuep; - return (1); -} - #define NORMAL 0 #define TRAP 1 #define INTERRUPT 2 @@ -304,7 +267,7 @@ db_nextframe(struct amd64_frame **fp, db tf = (struct trapframe *)((long)*fp + 16); if (INKERNEL((long) tf)) { - rsp = get_rsp(tf); + rsp = tf->tf_rsp; rip = tf->tf_rip; rbp = tf->tf_rbp; switch (frame_type) { @@ -380,20 +343,20 @@ db_backtrace(struct thread *td, struct t instr = db_get_value(pc, 4, FALSE); if ((instr & 0xffffffff) == 0xe5894855) { /* pushq %rbp; movq %rsp, %rbp */ - actframe = (void *)(get_rsp(tf) - 8); + actframe = (void *)(tf->tf_rsp - 8); } else if ((instr & 0xffffff) == 0xe58948) { /* movq %rsp, %rbp */ - actframe = (void *)get_rsp(tf); + actframe = (void *)tf->tf_rsp; if (tf->tf_rbp == 0) { /* Fake frame better. */ frame = actframe; } } else if ((instr & 0xff) == 0xc3) { /* ret */ - actframe = (void *)(get_rsp(tf) - 8); + actframe = (void *)(tf->tf_rsp - 8); } else if (offset == 0) { /* Probably an assembler symbol. */ - actframe = (void *)(get_rsp(tf) - 8); + actframe = (void *)(tf->tf_rsp - 8); } } else if (strcmp(name, "fork_trampoline") == 0) { /* @@ -448,9 +411,11 @@ int db_trace_thread(struct thread *thr, int count) { struct pcb *ctx; + struct trapframe *tf; ctx = kdb_thr_ctx(thr); - return (db_backtrace(thr, NULL, (struct amd64_frame *)ctx->pcb_rbp, + tf = thr == kdb_thread ? kdb_frame : NULL; + return (db_backtrace(thr, tf, (struct amd64_frame *)ctx->pcb_rbp, ctx->pcb_rip, ctx->pcb_rsp, count)); } Modified: head/sys/i386/i386/db_trace.c ============================================================================== --- head/sys/i386/i386/db_trace.c Tue Jul 21 23:13:11 2015 (r285775) +++ head/sys/i386/i386/db_trace.c Tue Jul 21 23:22:23 2015 (r285776) @@ -541,9 +541,11 @@ int db_trace_thread(struct thread *thr, int count) { struct pcb *ctx; + struct trapframe *tf; ctx = kdb_thr_ctx(thr); - return (db_backtrace(thr, NULL, (struct i386_frame *)ctx->pcb_ebp, + tf = thr == kdb_thread ? kdb_frame : NULL; + return (db_backtrace(thr, tf, (struct i386_frame *)ctx->pcb_ebp, ctx->pcb_eip, ctx->pcb_esp, count)); }