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Diffstat (limited to 'system/watchpoint.c')
| -rw-r--r-- | system/watchpoint.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/system/watchpoint.c b/system/watchpoint.c new file mode 100644 index 0000000000..45d1f12faf --- /dev/null +++ b/system/watchpoint.c @@ -0,0 +1,226 @@ +/* + * CPU watchpoints + * + * Copyright (c) 2003 Fabrice Bellard + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "qemu/osdep.h" +#include "qemu/main-loop.h" +#include "qemu/error-report.h" +#include "exec/exec-all.h" +#include "exec/translate-all.h" +#include "sysemu/tcg.h" +#include "sysemu/replay.h" +#include "hw/core/tcg-cpu-ops.h" +#include "hw/core/cpu.h" + +/* Add a watchpoint. */ +int cpu_watchpoint_insert(CPUState *cpu, vaddr addr, vaddr len, + int flags, CPUWatchpoint **watchpoint) +{ + CPUWatchpoint *wp; + vaddr in_page; + + /* forbid ranges which are empty or run off the end of the address space */ + if (len == 0 || (addr + len - 1) < addr) { + error_report("tried to set invalid watchpoint at %" + VADDR_PRIx ", len=%" VADDR_PRIu, addr, len); + return -EINVAL; + } + wp = g_malloc(sizeof(*wp)); + + wp->vaddr = addr; + wp->len = len; + wp->flags = flags; + + /* keep all GDB-injected watchpoints in front */ + if (flags & BP_GDB) { + QTAILQ_INSERT_HEAD(&cpu->watchpoints, wp, entry); + } else { + QTAILQ_INSERT_TAIL(&cpu->watchpoints, wp, entry); + } + + in_page = -(addr | TARGET_PAGE_MASK); + if (len <= in_page) { + tlb_flush_page(cpu, addr); + } else { + tlb_flush(cpu); + } + + if (watchpoint) { + *watchpoint = wp; + } + return 0; +} + +/* Remove a specific watchpoint. */ +int cpu_watchpoint_remove(CPUState *cpu, vaddr addr, vaddr len, + int flags) +{ + CPUWatchpoint *wp; + + QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) { + if (addr == wp->vaddr && len == wp->len + && flags == (wp->flags & ~BP_WATCHPOINT_HIT)) { + cpu_watchpoint_remove_by_ref(cpu, wp); + return 0; + } + } + return -ENOENT; +} + +/* Remove a specific watchpoint by reference. */ +void cpu_watchpoint_remove_by_ref(CPUState *cpu, CPUWatchpoint *watchpoint) +{ + QTAILQ_REMOVE(&cpu->watchpoints, watchpoint, entry); + + tlb_flush_page(cpu, watchpoint->vaddr); + + g_free(watchpoint); +} + +/* Remove all matching watchpoints. */ +void cpu_watchpoint_remove_all(CPUState *cpu, int mask) +{ + CPUWatchpoint *wp, *next; + + QTAILQ_FOREACH_SAFE(wp, &cpu->watchpoints, entry, next) { + if (wp->flags & mask) { + cpu_watchpoint_remove_by_ref(cpu, wp); + } + } +} + +#ifdef CONFIG_TCG + +/* + * Return true if this watchpoint address matches the specified + * access (ie the address range covered by the watchpoint overlaps + * partially or completely with the address range covered by the + * access). + */ +static inline bool watchpoint_address_matches(CPUWatchpoint *wp, + vaddr addr, vaddr len) +{ + /* + * We know the lengths are non-zero, but a little caution is + * required to avoid errors in the case where the range ends + * exactly at the top of the address space and so addr + len + * wraps round to zero. + */ + vaddr wpend = wp->vaddr + wp->len - 1; + vaddr addrend = addr + len - 1; + + return !(addr > wpend || wp->vaddr > addrend); +} + +/* Return flags for watchpoints that match addr + prot. */ +int cpu_watchpoint_address_matches(CPUState *cpu, vaddr addr, vaddr len) +{ + CPUWatchpoint *wp; + int ret = 0; + + QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) { + if (watchpoint_address_matches(wp, addr, len)) { + ret |= wp->flags; + } + } + return ret; +} + +/* Generate a debug exception if a watchpoint has been hit. */ +void cpu_check_watchpoint(CPUState *cpu, vaddr addr, vaddr len, + MemTxAttrs attrs, int flags, uintptr_t ra) +{ + CPUClass *cc = CPU_GET_CLASS(cpu); + CPUWatchpoint *wp; + + assert(tcg_enabled()); + if (cpu->watchpoint_hit) { + /* + * We re-entered the check after replacing the TB. + * Now raise the debug interrupt so that it will + * trigger after the current instruction. + */ + qemu_mutex_lock_iothread(); + cpu_interrupt(cpu, CPU_INTERRUPT_DEBUG); + qemu_mutex_unlock_iothread(); + return; + } + + if (cc->tcg_ops->adjust_watchpoint_address) { + /* this is currently used only by ARM BE32 */ + addr = cc->tcg_ops->adjust_watchpoint_address(cpu, addr, len); + } + + assert((flags & ~BP_MEM_ACCESS) == 0); + QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) { + int hit_flags = wp->flags & flags; + + if (hit_flags && watchpoint_address_matches(wp, addr, len)) { + if (replay_running_debug()) { + /* + * replay_breakpoint reads icount. + * Force recompile to succeed, because icount may + * be read only at the end of the block. + */ + if (!cpu->neg.can_do_io) { + /* Force execution of one insn next time. */ + cpu->cflags_next_tb = 1 | CF_LAST_IO | CF_NOIRQ + | curr_cflags(cpu); + cpu_loop_exit_restore(cpu, ra); + } + /* + * Don't process the watchpoints when we are + * in a reverse debugging operation. + */ + replay_breakpoint(); + return; + } + + wp->flags |= hit_flags << BP_HIT_SHIFT; + wp->hitaddr = MAX(addr, wp->vaddr); + wp->hitattrs = attrs; + + if (wp->flags & BP_CPU + && cc->tcg_ops->debug_check_watchpoint + && !cc->tcg_ops->debug_check_watchpoint(cpu, wp)) { + wp->flags &= ~BP_WATCHPOINT_HIT; + continue; + } + cpu->watchpoint_hit = wp; + + mmap_lock(); + /* This call also restores vCPU state */ + tb_check_watchpoint(cpu, ra); + if (wp->flags & BP_STOP_BEFORE_ACCESS) { + cpu->exception_index = EXCP_DEBUG; + mmap_unlock(); + cpu_loop_exit(cpu); + } else { + /* Force execution of one insn next time. */ + cpu->cflags_next_tb = 1 | CF_LAST_IO | CF_NOIRQ + | curr_cflags(cpu); + mmap_unlock(); + cpu_loop_exit_noexc(cpu); + } + } else { + wp->flags &= ~BP_WATCHPOINT_HIT; + } + } +} + +#endif /* CONFIG_TCG */ |