There is no particular reason why you can't have a watchpoint in TCG
that covers a large chunk of the address space. We could be clever
about it but these cases are pretty rare and we can assume the user
will expect a little performance degradation.
NB: In my testing gdb will silently squash a watchpoint like:
watch (char[0x7fffffffff]) *0x0
to a 4 byte watchpoint. Practically it will limit the maximum size
based on max-value-size. However given enough of a tweak the sky is
the limit.
Reported-by: Alexander Bulekov <alx...@bu.edu>
Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
---
exec.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/exec.c b/exec.c
index 5162f0d12f9..851ac180fe7 100644
--- a/exec.c
+++ b/exec.c
@@ -1056,7 +1056,11 @@ int cpu_watchpoint_insert(CPUState *cpu, vaddr addr,
vaddr len,
QTAILQ_INSERT_TAIL(&cpu->watchpoints, wp, entry);
}
- tlb_flush_page(cpu, addr);
+ if (((addr + len) & TARGET_PAGE_MASK) != (addr & TARGET_PAGE_MASK)) {
+ tlb_flush(cpu);
+ } else {
+ tlb_flush_page(cpu, addr);
+ }
if (watchpoint)
*watchpoint = wp;
--
2.20.1
