diff options
| -rw-r--r-- | gdb/ChangeLog | 15 | ||||
| -rw-r--r-- | gdb/i386v-nat.c | 175 | ||||
| -rw-r--r-- | gdb/infrun.c | 5 |
3 files changed, 194 insertions, 1 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 72eca92..5b37c43 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,18 @@ +Wed Jun 1 11:08:52 1994 Stan Shebs (shebs@andros.cygnus.com) + + Hardware watchpoints for Linux, from Rick Sladkey + (jrs@world.std.com). + * infrun.c (wait_for_inferior) [HAVE_CONTINUABLE_WATCHPOINT]: Add + new hardware breakpoint recovery method. + * i386v-nat.c (i386_insert_watchpoint, + i386_insert_nonaligned_watchpoint, i386_remove_watchpoint, + i386_stopped_by_watchpoint) [TARGET_CAN_USE_HARWARE_WATCHPOINT]: + New functions to support the 386 hardware debugging registers. + * config/i386/nm-linux.h (TARGET_CAN_USE_HARDWARE_WATCHPOINT, + HAVE_CONTINUABLE_WATCHPOINT, STOPPED_BY_WATCHPOINT, + target_insert_watchpoint, target_remove_watchpoint): Define these + macros to use the hardware debugging functions in i386v-nat.c. + Wed May 25 17:06:15 1994 Jim Kingdon (kingdon@lioth.cygnus.com) * Makefile.in: Replace libgdb.a with libgdb-files. Make "all" diff --git a/gdb/i386v-nat.c b/gdb/i386v-nat.c index 1a6213a..25d3d93 100644 --- a/gdb/i386v-nat.c +++ b/gdb/i386v-nat.c @@ -1,5 +1,5 @@ /* Intel 386 native support for SYSV systems (pre-SVR4). - Copyright (C) 1988, 1989, 1991, 1992 Free Software Foundation, Inc. + Copyright (C) 1988, 1989, 1991, 1992, 1994 Free Software Foundation, Inc. This file is part of GDB. @@ -34,6 +34,10 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <sys/ioctl.h> #include <fcntl.h> +#ifdef TARGET_CAN_USE_HARDWARE_WATCHPOINT +#include <sys/debugreg.h> +#endif + #include <sys/file.h> #include <sys/stat.h> @@ -83,6 +87,175 @@ i386_register_u_addr (blockend, regnum) return (blockend + 4 * regmap[regnum]); } + +#ifdef TARGET_CAN_USE_HARDWARE_WATCHPOINT + +#if !defined (offsetof) +#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER) +#endif + +/* Record the value of the debug control register. */ +static int debug_control_mirror; + +/* Record which address associates with which register. */ +static CORE_ADDR address_lookup[DR_LASTADDR - DR_FIRSTADDR + 1]; + +static int +i386_insert_nonaligned_watchpoint PARAMS ((int, CORE_ADDR, int, int)); + +/* Insert a watchpoint. */ + +int +i386_insert_watchpoint (pid, addr, len, rw) + int pid; + CORE_ADDR addr; + int len; + int rw; +{ + int i; + int read_write_bits, len_bits; + int free_debug_register; + int register_number; + + /* Look for a free debug register. */ + for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++) + { + if (address_lookup[i - DR_FIRSTADDR] == 0) + break; + } + + /* No more debug registers! */ + if (i > DR_LASTADDR) + return -1; + + read_write_bits = ((rw & 1) ? DR_RW_READ : 0) | ((rw & 2) ? DR_RW_WRITE : 0); + + if (len == 1) + len_bits = DR_LEN_1; + else if (len == 2) + { + if (addr % 2) + return i386_insert_nonaligned_watchpoint (pid, addr, len, rw); + len_bits = DR_LEN_2; + } + + else if (len == 4) + { + if (addr % 4) + return i386_insert_nonaligned_watchpoint (pid, addr, len, rw); + len_bits = DR_LEN_4; + } + else + return i386_insert_nonaligned_watchpoint (pid, addr, len, rw); + + free_debug_register = i; + register_number = free_debug_register - DR_FIRSTADDR; + debug_control_mirror |= + ((read_write_bits | len_bits) + << (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * register_number)); + debug_control_mirror |= + (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * register_number)); + debug_control_mirror |= DR_LOCAL_SLOWDOWN; + debug_control_mirror &= ~DR_CONTROL_RESERVED; + + ptrace (6, pid, offsetof (struct user, u_debugreg[DR_CONTROL]), + debug_control_mirror); + ptrace (6, pid, offsetof (struct user, u_debugreg[free_debug_register]), + addr); + + /* Record where we came from. */ + address_lookup[register_number] = addr; + return 0; +} + +static int +i386_insert_nonaligned_watchpoint (pid, addr, len, rw) + int pid; + CORE_ADDR addr; + int len; + int rw; +{ + int align; + int size; + int rv; + + static int size_try_array[16] = { + 1, 1, 1, 1, /* trying size one */ + 2, 1, 2, 1, /* trying size two */ + 2, 1, 2, 1, /* trying size three */ + 4, 1, 2, 1 /* trying size four */ + }; + + rv = 0; + while (len > 0) + { + align = addr % 4; + /* Four is the maximum length for 386. */ + size = (len > 4) ? 3 : len - 1; + size = size_try_array[size * 4 + align]; + + rv = i386_insert_watchpoint (pid, addr, size, rw); + if (rv) + { + i386_remove_watchpoint (pid, addr, size); + return rv; + } + addr += size; + len -= size; + } + return rv; +} + +/* Remove a watchpoint. */ + +int +i386_remove_watchpoint (pid, addr, len) + int pid; + CORE_ADDR addr; + int len; +{ + int i; + int register_number; + + for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++) + { + register_number = i - DR_FIRSTADDR; + if (address_lookup[register_number] == addr) + { + debug_control_mirror &= + ~(1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * register_number)); + address_lookup[register_number] = 0; + } + } + ptrace (6, pid, offsetof (struct user, u_debugreg[DR_CONTROL]), + debug_control_mirror); + ptrace (6, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0); + + return 0; +} + +/* Check if stopped by a watchpoint. */ + +CORE_ADDR +i386_stopped_by_watchpoint (pid) + int pid; +{ + int i; + int status; + + status = ptrace (3, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0); + ptrace (6, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0); + + for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++) + { + if (status & (1 << (i - DR_FIRSTADDR))) + return address_lookup[i - DR_FIRSTADDR]; + } + + return 0; +} + +#endif /* TARGET_CAN_USE_HARDWARE_WATCHPOINT */ #if 0 /* using FLOAT_INFO as is would be a problem. FLOAT_INFO is called diff --git a/gdb/infrun.c b/gdb/infrun.c index 4c39237..08e3bfd 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -680,6 +680,11 @@ switch_thread: } #endif +#ifdef HAVE_CONTINUABLE_WATCHPOINT + /* It may be possible to simply continue after a watchpoint. */ + STOPPED_BY_WATCHPOINT (w); +#endif + stop_frame_address = FRAME_FP (get_current_frame ()); stop_sp = read_sp (); stop_func_start = 0; |