diff mbox series

[PULL,02/12] gdbstub: Fix handler for 'F' packet

Message ID 20190902102122.1128-3-alex.bennee@linaro.org (mailing list archive)
State New, archived
Headers show
Series [PULL,01/12] gdbstub: Fix handling of '!' packet with new infra | expand

Commit Message

Alex Bennée Sept. 2, 2019, 10:21 a.m. UTC 
From: Sandra Loosemore <sandra@codesourcery.com>

Handling of the 'F' packet has been broken since commit
4b20fab101b9e2d0fb47454209637a17fc7a13d5, which converted it to use
the new packet parsing infrastructure.  Per the GDB RSP specification

https://sourceware.org/gdb/current/onlinedocs/gdb/The-F-Reply-Packet.html

the second parameter may be omitted, but the rewritten implementation
was failing to recognize this case.  The result was that QEMU was
repeatedly resending the fileio request and ignoring GDB's replies of
successful completion.  This patch restores the behavior of the
previous code in allowing the errno parameter to be omitted and
passing 0 to the callback in that case.

Signed-off-by: Sandra Loosemore <sandra@codesourcery.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190827223317.8614-1-sandra@codesourcery.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
diff mbox series

Patch

diff --git a/gdbstub.c b/gdbstub.c
index 5c067594bae..4cf8af365e2 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -1820,11 +1820,15 @@  static void handle_read_all_regs(GdbCmdContext *gdb_ctx, void *user_ctx)
 
 static void handle_file_io(GdbCmdContext *gdb_ctx, void *user_ctx)
 {
-    if (gdb_ctx->num_params >= 2 && gdb_ctx->s->current_syscall_cb) {
+    if (gdb_ctx->num_params >= 1 && gdb_ctx->s->current_syscall_cb) {
         target_ulong ret, err;
 
         ret = (target_ulong)gdb_ctx->params[0].val_ull;
-        err = (target_ulong)gdb_ctx->params[1].val_ull;
+        if (gdb_ctx->num_params >= 2) {
+            err = (target_ulong)gdb_ctx->params[1].val_ull;
+        } else {
+            err = 0;
+        }
         gdb_ctx->s->current_syscall_cb(gdb_ctx->s->c_cpu, ret, err);
         gdb_ctx->s->current_syscall_cb = NULL;
     }