Date: Sun, 14 Aug 2016 16:51:26 +0000 (UTC) From: Bruce Evans <bde@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r304085 - in head/sys/i386: i386 include Message-ID: <201608141651.u7EGpQRr095942@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: bde Date: Sun Aug 14 16:51:25 2016 New Revision: 304085 URL: https://svnweb.freebsd.org/changeset/base/304085 Log: Fix the variables $esp, $ds, $es, $fs, $gs and $ss in vm86 mode. Fix PC_REGS() so that printing of instructions works in some useful cases. ddb only understands a single flat address space, but this macro allows mapping $cs:$eip into vm86's flat address space well enough for the MI parts of ddb. This doesn't work for the MD parts that do stack traces, and there are no similar macros for data addresses. PC_REGS() has to use the trapframe pointer instead of the pcb for this. For other CPUs, the trapframe pointer is not available except by tracing back to it. But tracing back through vm86 trapframes is broken even starting with one. Modified: head/sys/i386/i386/db_trace.c head/sys/i386/include/db_machdep.h Modified: head/sys/i386/i386/db_trace.c ============================================================================== --- head/sys/i386/i386/db_trace.c Sun Aug 14 16:32:23 2016 (r304084) +++ head/sys/i386/i386/db_trace.c Sun Aug 14 16:51:25 2016 (r304085) @@ -34,6 +34,7 @@ __FBSDID("$FreeBSD$"); #include <sys/sysent.h> #include <machine/cpu.h> +#include <machine/frame.h> #include <machine/md_var.h> #include <machine/pcb.h> #include <machine/reg.h> @@ -81,8 +82,8 @@ struct db_variable *db_eregs = db_regs + static __inline int get_esp(struct trapframe *tf) { - return ((ISPL(tf->tf_cs)) ? tf->tf_esp : - (db_expr_t)tf + (uintptr_t)DB_OFFSET(tf_esp)); + return ((ISPL(tf->tf_cs) || kdb_frame->tf_eflags & PSL_VM) ? + tf->tf_esp : (intptr_t)&tf->tf_esp); } static int @@ -104,12 +105,32 @@ db_frame(struct db_variable *vp, db_expr static int db_frame_seg(struct db_variable *vp, db_expr_t *valuep, int op) { + struct trapframe_vm86 *tfp; + int off; uint16_t *reg; if (kdb_frame == NULL) return (0); - reg = (uint16_t *)((uintptr_t)kdb_frame + (db_expr_t)vp->valuep); + off = (intptr_t)vp->valuep; + if (kdb_frame->tf_eflags & PSL_VM) { + tfp = (void *)kdb_frame; + switch ((intptr_t)vp->valuep) { + case (intptr_t)DB_OFFSET(tf_cs): + reg = (uint16_t *)&tfp->tf_cs; + break; + case (intptr_t)DB_OFFSET(tf_ds): + reg = (uint16_t *)&tfp->tf_vm86_ds; + break; + case (intptr_t)DB_OFFSET(tf_es): + reg = (uint16_t *)&tfp->tf_vm86_es; + break; + case (intptr_t)DB_OFFSET(tf_fs): + reg = (uint16_t *)&tfp->tf_vm86_fs; + break; + } + } else + reg = (uint16_t *)((uintptr_t)kdb_frame + off); if (op == DB_VAR_GET) *valuep = *reg; else @@ -134,7 +155,16 @@ db_esp(struct db_variable *vp, db_expr_t static int db_gs(struct db_variable *vp, db_expr_t *valuep, int op) { + struct trapframe_vm86 *tfp; + if (kdb_frame != NULL && kdb_frame->tf_eflags & PSL_VM) { + tfp = (void *)kdb_frame; + if (op == DB_VAR_GET) + *valuep = tfp->tf_vm86_gs; + else + tfp->tf_vm86_gs = *valuep; + return (1); + } if (op == DB_VAR_GET) *valuep = rgs(); else @@ -150,8 +180,9 @@ db_ss(struct db_variable *vp, db_expr_t 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)) + *valuep = (ISPL(kdb_frame->tf_cs) || + kdb_frame->tf_eflags & PSL_VM) ? kdb_frame->tf_ss : rss(); + else if (ISPL(kdb_frame->tf_cs) || kdb_frame->tf_eflags & PSL_VM) kdb_frame->tf_ss = *valuep; return (1); } Modified: head/sys/i386/include/db_machdep.h ============================================================================== --- head/sys/i386/include/db_machdep.h Sun Aug 14 16:32:23 2016 (r304084) +++ head/sys/i386/include/db_machdep.h Sun Aug 14 16:51:25 2016 (r304085) @@ -35,7 +35,10 @@ typedef vm_offset_t db_addr_t; /* address - unsigned */ typedef int db_expr_t; /* expression - signed */ -#define PC_REGS() ((db_addr_t)kdb_thrctx->pcb_eip) +#define PC_REGS() ((db_addr_t)(kdb_frame->tf_eflags & PSL_VM ? \ + (kdb_frame->tf_eip & 0xffff) + \ + ((kdb_frame->tf_cs & 0xffff) << 4) : \ + kdb_frame->tf_eip)) #define BKPT_INST 0xcc /* breakpoint instruction */ #define BKPT_SIZE (1) /* size of breakpoint inst */
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201608141651.u7EGpQRr095942>