Florian Hofhammer <[email protected]> writes:
> The opaque register handle encodes whether a register is read-only in
> the lowest bit and prevents writing to the register via the plugin API
> in this case.
>
> Signed-off-by: Florian Hofhammer <[email protected]>
> ---
> plugins/api.c | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/plugins/api.c b/plugins/api.c
> index b2c52d2a09..3a8479ddce 100644
> --- a/plugins/api.c
> +++ b/plugins/api.c
> @@ -424,6 +424,7 @@ static GArray *create_register_handles(GArray
> *gdbstub_regs)
> for (int i = 0; i < gdbstub_regs->len; i++) {
> GDBRegDesc *grd = &g_array_index(gdbstub_regs, GDBRegDesc, i);
> qemu_plugin_reg_descriptor desc;
> + gint plugin_ro_bit = 0;
>
> /* skip "un-named" regs */
> if (!grd->name) {
> @@ -431,7 +432,6 @@ static GArray *create_register_handles(GArray
> *gdbstub_regs)
> }
>
> /* Create a record for the plugin */
> - desc.handle = GINT_TO_POINTER(grd->gdb_reg + 1);
> desc.name = g_intern_string(grd->name);
> desc.is_readonly = false;
> if (g_strcmp0(desc.name, pc_str) == 0
> @@ -442,7 +442,9 @@ static GArray *create_register_handles(GArray
> *gdbstub_regs)
> || g_strcmp0(desc.name, rpc_str) == 0
> ) {
> desc.is_readonly = true;
> + plugin_ro_bit = 1;
> }
> + desc.handle = GINT_TO_POINTER((grd->gdb_reg << 1) | plugin_ro_bit);
> desc.feature = g_intern_string(grd->feature_name);
> g_array_append_val(find_data, desc);
> }
> @@ -467,7 +469,7 @@ bool qemu_plugin_read_register(struct
> qemu_plugin_register *reg,
> return false;
> }
>
> - return (gdb_read_register(current_cpu, buf, GPOINTER_TO_INT(reg) - 1) >
> 0);
> + return (gdb_read_register(current_cpu, buf, GPOINTER_TO_INT(reg) >> 1) >
> 0);
> }
>
> bool qemu_plugin_write_register(struct qemu_plugin_register *reg,
> @@ -476,11 +478,12 @@ bool qemu_plugin_write_register(struct
> qemu_plugin_register *reg,
> g_assert(current_cpu);
>
> if (buf->len == 0 || (qemu_plugin_get_cb_flags() !=
> QEMU_PLUGIN_CB_RW_REGS &&
> - qemu_plugin_get_cb_flags() !=
> QEMU_PLUGIN_CB_RW_REGS_PC)) {
> + qemu_plugin_get_cb_flags() !=
> QEMU_PLUGIN_CB_RW_REGS_PC)
> + || (GPOINTER_TO_INT(reg) & 1)) {
Maybe this is better as:
g_assert(GPOINTER_TO_INT(reg) & 1 == 0);
if (buf->len == 0 || (qemu_plugin_get_cb_flags() !=
QEMU_PLUGIN_CB_RW_REGS &&...
again the plugin is trying to do something it shouldn't.
> return false;
> }
>
> - return (gdb_write_register(current_cpu, buf->data, GPOINTER_TO_INT(reg)
> - 1) > 0);
> + return (gdb_write_register(current_cpu, buf->data, GPOINTER_TO_INT(reg)
> >> 1) > 0);
> }
>
> void qemu_plugin_set_pc(uint64_t vaddr)
--
Alex Bennée
Virtualisation Tech Lead @ Linaro
