Module: wine
Branch: master
Commit: eb63a5f3c3c1851f212bd14f91da329bf3166e42
URL: https://source.winehq.org/git/wine.git/?a=commit;h=eb63a5f3c3c1851f212bd14f…
Author: Zebediah Figura <z.figura12(a)gmail.com>
Date: Sun Jan 14 19:01:15 2018 -0600
winedbg/gdbproxy: Replace memory read over a breakpoint with the real value.
Normally, when we hit a breakpoint, we remove it before stopping and add it
after continuing. gdb, however, reads the process memory before requesting
that the breakpoint be removed, and apparently caches it until the `stepi`
instruction is executed; as a result, it thinks that the interrupt byte that
is present in the code is an actual interrupt and not a breakpoint, and so
tries to step over it as one byte instead of executing the real instruction
at that location.
Signed-off-by: Zebediah Figura <z.figura12(a)gmail.com>
Signed-off-by: Alexandre Julliard <julliard(a)winehq.org>
---
programs/winedbg/gdbproxy.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/programs/winedbg/gdbproxy.c b/programs/winedbg/gdbproxy.c
index c02ad3b..7b9a476 100644
--- a/programs/winedbg/gdbproxy.c
+++ b/programs/winedbg/gdbproxy.c
@@ -1568,6 +1568,28 @@ static enum packet_return packet_thread(struct gdb_context* gdbctx)
}
}
+static BOOL read_memory(struct gdb_context *gdbctx, char *addr, char *buffer, SIZE_T blk_len, SIZE_T *r)
+{
+ /* Wrapper around process_io->read() that replaces values displaced by breakpoints. */
+
+ BOOL ret;
+
+ ret = gdbctx->process->process_io->read(gdbctx->process->handle, addr, buffer, blk_len, r);
+ if (ret)
+ {
+ struct gdb_ctx_Xpoint *xpt;
+
+ for (xpt = &gdbctx->Xpoints[NUM_XPOINT - 1]; xpt >= gdbctx->Xpoints; xpt--)
+ {
+ char *xpt_addr = xpt->addr;
+
+ if (xpt->type != -1 && xpt_addr >= addr && xpt_addr < addr + blk_len)
+ buffer[xpt_addr - addr] = xpt->val;
+ }
+ }
+ return ret;
+}
+
static enum packet_return packet_read_memory(struct gdb_context* gdbctx)
{
char *addr;
@@ -1584,8 +1606,7 @@ static enum packet_return packet_read_memory(struct gdb_context* gdbctx)
for (nread = 0; nread < len; nread += r, addr += r)
{
blk_len = min(sizeof(buffer), len - nread);
- if (!gdbctx->process->process_io->read(gdbctx->process->handle, addr, buffer, blk_len, &r) ||
- r == 0)
+ if (!read_memory(gdbctx, addr, buffer, blk_len, &r) || r == 0)
{
/* fail at first address, return error */
if (nread == 0) return packet_reply_error(gdbctx, EFAULT);