From c6ee95216b1a98c909e24659741622aaf563df86 Mon Sep 17 00:00:00 2001 From: Sandra Loosemore Date: Tue, 27 Aug 2019 16:33:17 -0600 Subject: [PATCH] gdbstub: Fix handler for 'F' packet MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Richard Henderson Message-Id: <20190827223317.8614-1-sandra@codesourcery.com> Signed-off-by: Alex Bennée --- gdbstub.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/gdbstub.c b/gdbstub.c index 5c067594ba..4cf8af365e 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; }