gdbstub: Fix handler for 'F' packet

Handling of the 'F' packet has been broken since commit
4b20fab101, 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>
This commit is contained in:
Sandra Loosemore 2019-08-27 16:33:17 -06:00 committed by Alex Bennée
parent 2bdec39848
commit c6ee95216b

View File

@ -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;
}