| /* Misc. low level support for i386. |
| |
| Copyright (C) 2009, 2010 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| /* Support for hardware watchpoints and breakpoints using the i386 |
| debug registers. |
| |
| This provides several functions for inserting and removing |
| hardware-assisted breakpoints and watchpoints, testing if one or |
| more of the watchpoints triggered and at what address, checking |
| whether a given region can be watched, etc. |
| |
| The functions below implement debug registers sharing by reference |
| counts, and allow to watch regions up to 16 bytes long |
| (32 bytes on 64 bit hosts). */ |
| |
| |
| /* Debug registers' indices. */ |
| #define DR_FIRSTADDR 0 |
| #define DR_LASTADDR 3 |
| #define DR_NADDR 4 /* The number of debug address registers. */ |
| #define DR_STATUS 6 |
| #define DR_CONTROL 7 |
| |
| /* Global state needed to track h/w watchpoints. */ |
| |
| struct i386_debug_reg_state |
| { |
| /* Mirror the inferior's DRi registers. We keep the status and |
| control registers separated because they don't hold addresses. |
| Note that since we can change these mirrors while threads are |
| running, we never trust them to explain a cause of a trap. |
| For that, we need to peek directly in the inferior registers. */ |
| CORE_ADDR dr_mirror[DR_NADDR]; |
| unsigned dr_status_mirror, dr_control_mirror; |
| |
| /* Reference counts for each debug register. */ |
| int dr_ref_count[DR_NADDR]; |
| }; |
| |
| /* Initialize STATE. */ |
| extern void i386_low_init_dregs (struct i386_debug_reg_state *state); |
| |
| /* Insert a watchpoint to watch a memory region which starts at |
| address ADDR and whose length is LEN bytes. Watch memory accesses |
| of the type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */ |
| extern int i386_low_insert_watchpoint (struct i386_debug_reg_state *state, |
| char type_from_packet, CORE_ADDR addr, |
| int len); |
| |
| /* Remove a watchpoint that watched the memory region which starts at |
| address ADDR, whose length is LEN bytes, and for accesses of the |
| type TYPE_FROM_PACKET. Return 0 on success, -1 on failure. */ |
| extern int i386_low_remove_watchpoint (struct i386_debug_reg_state *state, |
| char type_from_packet, CORE_ADDR addr, |
| int len); |
| |
| /* Return non-zero if we can watch a memory region that starts at |
| address ADDR and whose length is LEN bytes. */ |
| extern int i386_low_region_ok_for_watchpoint (struct i386_debug_reg_state *state, |
| CORE_ADDR addr, int len); |
| |
| /* If the inferior has some break/watchpoint that triggered, set the |
| address associated with that break/watchpoint and return true. |
| Otherwise, return false. */ |
| extern int i386_low_stopped_data_address (struct i386_debug_reg_state *state, |
| CORE_ADDR *addr_p); |
| |
| /* Return true if the inferior has some watchpoint that triggered. |
| Otherwise return false. */ |
| extern int i386_low_stopped_by_watchpoint (struct i386_debug_reg_state *state); |
| |
| /* Each target needs to provide several low-level functions |
| that will be called to insert watchpoints and hardware breakpoints |
| into the inferior, remove them, and check their status. These |
| functions are: |
| |
| i386_dr_low_set_control -- set the debug control (DR7) |
| register to a given value |
| |
| i386_dr_low_set_addr -- put an address into one debug register |
| |
| i386_dr_low_get_status -- return the value of the debug |
| status (DR6) register. |
| */ |
| |
| /* Update the inferior's debug register REGNUM from STATE. */ |
| extern void i386_dr_low_set_addr (const struct i386_debug_reg_state *state, |
| int regnum); |
| |
| /* Return the inferior's debug register REGNUM. */ |
| extern CORE_ADDR i386_dr_low_get_addr (int regnum); |
| |
| /* Update the inferior's DR7 debug control register from STATE. */ |
| extern void i386_dr_low_set_control (const struct i386_debug_reg_state *state); |
| |
| /* Return the value of the inferior's DR7 debug control register. */ |
| extern unsigned i386_dr_low_get_control (void); |
| |
| /* Return the value of the inferior's DR6 debug status register. */ |
| extern unsigned i386_dr_low_get_status (void); |