On Thu, Apr 09, 2020 at 10:15:27PM +0100, Alex Bennée wrote:
> From: Peter Xu <pet...@redhat.com>
>
> We should only pass in gdb_get_reg16() with the GByteArray* object
> itself, no need to shift. Without this patch, gdb remote attach will
> crash QEMU.
>
> Fixes: a010bdbe719 ("extend GByteArray to read register helpers")
> Signed-off-by: Peter Xu <pet...@redhat.com>
> Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
> Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
> Message-Id: <20200409164954.36902-3-pet...@redhat.com>
> ---
> target/i386/gdbstub.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/target/i386/gdbstub.c b/target/i386/gdbstub.c
> index f3d23b614ee..b98a99500ae 100644
> --- a/target/i386/gdbstub.c
> +++ b/target/i386/gdbstub.c
> @@ -106,7 +106,7 @@ int x86_cpu_gdb_read_register(CPUState *cs, GByteArray
> *mem_buf, int n)
> } else if (n >= IDX_FP_REGS && n < IDX_FP_REGS + 8) {
> floatx80 *fp = (floatx80 *) &env->fpregs[n - IDX_FP_REGS];
> int len = gdb_get_reg64(mem_buf, cpu_to_le64(fp->low));
> - len += gdb_get_reg16(mem_buf + len, cpu_to_le16(fp->high));
> + len += gdb_get_reg16(mem_buf, cpu_to_le16(fp->high));
> return len;
> } else if (n >= IDX_XMM_REGS && n < IDX_XMM_REGS + CPU_NB_REGS) {
> n -= IDX_XMM_REGS;
> --
> 2.20.1
>
>
I had the following issue while attaching to qemu started with gdbserver
listening:
(gdb) target remote :1234
Remote debugging using :1234
Remote communication error. Target disconnected.: Connection reset by peer.
$ qemu-system-x86_64 -m 1G -smp 4 ... -s
ERROR:qemu/gdbstub.c:1843:handle_read_all_regs: assertion failed: (len ==
gdbserver_state.mem_buf->len)
Bail out! ERROR:qemu/gdbstub.c:1843:handle_read_all_regs: assertion failed:
(len == gdbserver_state.mem_buf->len)
Thanks to Philippe, I tried this patch and it solves my issue:
Tested-by: Stefano Garzarella <sgarz...@redhat.com>
Thanks,
Stefano
