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Diffstat (limited to 'exec.c')
-rw-r--r--exec.c44
1 files changed, 31 insertions, 13 deletions
diff --git a/exec.c b/exec.c
index 7dddcc8034..f3e7fb6bcf 100644
--- a/exec.c
+++ b/exec.c
@@ -582,12 +582,10 @@ int cpu_watchpoint_insert(CPUState *cpu, vaddr addr, vaddr len,
int cpu_watchpoint_insert(CPUState *cpu, vaddr addr, vaddr len,
int flags, CPUWatchpoint **watchpoint)
{
- vaddr len_mask = ~(len - 1);
CPUWatchpoint *wp;
- /* sanity checks: allow power-of-2 lengths, deny unaligned watchpoints */
- if ((len & (len - 1)) || (addr & ~len_mask) ||
- len == 0 || len > TARGET_PAGE_SIZE) {
+ /* 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;
@@ -595,7 +593,7 @@ int cpu_watchpoint_insert(CPUState *cpu, vaddr addr, vaddr len,
wp = g_malloc(sizeof(*wp));
wp->vaddr = addr;
- wp->len_mask = len_mask;
+ wp->len = len;
wp->flags = flags;
/* keep all GDB-injected watchpoints in front */
@@ -616,11 +614,10 @@ int cpu_watchpoint_insert(CPUState *cpu, vaddr addr, vaddr len,
int cpu_watchpoint_remove(CPUState *cpu, vaddr addr, vaddr len,
int flags)
{
- vaddr len_mask = ~(len - 1);
CPUWatchpoint *wp;
QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
- if (addr == wp->vaddr && len_mask == wp->len_mask
+ if (addr == wp->vaddr && len == wp->len
&& flags == (wp->flags & ~BP_WATCHPOINT_HIT)) {
cpu_watchpoint_remove_by_ref(cpu, wp);
return 0;
@@ -650,6 +647,27 @@ void cpu_watchpoint_remove_all(CPUState *cpu, int mask)
}
}
}
+
+/* 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 cpu_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);
+}
+
#endif
/* Add a breakpoint. */
@@ -861,7 +879,7 @@ hwaddr memory_region_section_get_iotlb(CPUState *cpu,
/* Make accesses to pages with watchpoints go via the
watchpoint trap routines. */
QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
- if (vaddr == (wp->vaddr & TARGET_PAGE_MASK)) {
+ if (cpu_watchpoint_address_matches(wp, vaddr, TARGET_PAGE_SIZE)) {
/* Avoid trapping reads of pages with a write breakpoint. */
if ((prot & PAGE_WRITE) || (wp->flags & BP_MEM_READ)) {
iotlb = PHYS_SECTION_WATCH + paddr;
@@ -1625,7 +1643,7 @@ static const MemoryRegionOps notdirty_mem_ops = {
};
/* Generate a debug exception if a watchpoint has been hit. */
-static void check_watchpoint(int offset, int len_mask, int flags)
+static void check_watchpoint(int offset, int len, int flags)
{
CPUState *cpu = current_cpu;
CPUArchState *env = cpu->env_ptr;
@@ -1643,8 +1661,8 @@ static void check_watchpoint(int offset, int len_mask, int flags)
}
vaddr = (cpu->mem_io_vaddr & TARGET_PAGE_MASK) + offset;
QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
- if ((vaddr == (wp->vaddr & len_mask) ||
- (vaddr & wp->len_mask) == wp->vaddr) && (wp->flags & flags)) {
+ if (cpu_watchpoint_address_matches(wp, vaddr, len)
+ && (wp->flags & flags)) {
wp->flags |= BP_WATCHPOINT_HIT;
if (!cpu->watchpoint_hit) {
cpu->watchpoint_hit = wp;
@@ -1670,7 +1688,7 @@ static void check_watchpoint(int offset, int len_mask, int flags)
static uint64_t watch_mem_read(void *opaque, hwaddr addr,
unsigned size)
{
- check_watchpoint(addr & ~TARGET_PAGE_MASK, ~(size - 1), BP_MEM_READ);
+ check_watchpoint(addr & ~TARGET_PAGE_MASK, size, BP_MEM_READ);
switch (size) {
case 1: return ldub_phys(&address_space_memory, addr);
case 2: return lduw_phys(&address_space_memory, addr);
@@ -1682,7 +1700,7 @@ static uint64_t watch_mem_read(void *opaque, hwaddr addr,
static void watch_mem_write(void *opaque, hwaddr addr,
uint64_t val, unsigned size)
{
- check_watchpoint(addr & ~TARGET_PAGE_MASK, ~(size - 1), BP_MEM_WRITE);
+ check_watchpoint(addr & ~TARGET_PAGE_MASK, size, BP_MEM_WRITE);
switch (size) {
case 1:
stb_phys(&address_space_memory, addr, val);