Re: [PATCH 2/2] gdbstub: i386: Fix gdb_get_reg16() parameter to unbreak gdb

[Philippe Mathieu-Daudé]

On 4/9/20 6:49 PM, Peter Xu wrote:
> 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.

You are correct.

Fixes: a010bdbe719 ("extend GByteArray to read register helpers")

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

Same problem in m68k_fpu_gdb_get_reg().

TODO for 5.1, rename mem_buf -> array.

> Cc: Alex Bennée <address@hidden>
> Cc: Philippe Mathieu-Daudé <address@hidden>
> Signed-off-by: Peter Xu <address@hidden>
> ---
>   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 f3d23b614e..b98a99500a 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;