From bbc40fefcee0d69d61ceaf8c0695d2ce43cdc87b Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Tue, 14 Apr 2020 21:06:25 +0100 Subject: [PATCH] gdbstub: i386: Fix gdb_get_reg16() parameter to unbreak gdb MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: (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) Fixes: a010bdbe719 ("extend GByteArray to read register helpers") Signed-off-by: Peter Xu Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Alex Bennée Tested-by: Stefano Garzarella Reviewed-by: Richard Henderson Message-Id: <20200409164954.36902-3-peterx@redhat.com> Message-Id: <20200414200631.12799-12-alex.bennee@linaro.org> --- 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;