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[v2,2/2] gdbstub: i386: Fix gdb_get_reg16() parameter to unbreak gdb

Message ID 20200409182538.40816-3-peterx@redhat.com (mailing list archive)
State New, archived
Headers show
Series gdbstub: Unbreak i386 with gdb remote | expand

Commit Message

Peter Xu April 9, 2020, 6:25 p.m. UTC
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.

Cc: Alex Bennée <alex.bennee@linaro.org>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Fixes: b7b8756a9c ("target/i386: use gdb_get_reg helpers", 2020-03-17)
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 target/i386/gdbstub.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Peter Xu April 9, 2020, 6:56 p.m. UTC | #1
On Thu, Apr 09, 2020 at 02:25:38PM -0400, 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.
> 
> Cc: Alex Bennée <alex.bennee@linaro.org>
> Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
> Fixes: b7b8756a9c ("target/i386: use gdb_get_reg helpers", 2020-03-17)

So I think this should still be:

Fixes: a010bdbe71 ("gdbstub: extend GByteArray to read register helpers")

As Phil & Laurent pointed out.

> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> Signed-off-by: Peter Xu <peterx@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 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;
> -- 
> 2.24.1
>
diff mbox series

Patch

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;