Commit 4f710866 authored by Peter Maydell's avatar Peter Maydell Committed by Laurent Vivier
Browse files

gdbstub: Clarify what gdb_handlesig() is doing 



gdb_handlesig()'s behaviour is not entirely obvious at first
glance. Add a doc comment for it, and also add a comment
explaining why it's ok for gdb_do_syscallv() to ignore
gdb_handlesig()'s return value. (Coverity complains about
this: CID 1390850.)

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Message-Id: <20180515181958.25837-1-peter.maydell@linaro.org>
Signed-off-by: default avatarLaurent Vivier <laurent@vivier.eu>
parent b0a7413d

gdbstub.c

+6 −0
Original line number Diff line number Diff line
@@ -1558,6 +1558,12 @@ void gdb_do_syscallv(gdb_syscall_complete_cb cb, const char *fmt, va_list va) 
    *p = 0;

#ifdef CONFIG_USER_ONLY

    put_packet(s, s->syscall_buf);

    /* Return control to gdb for it to process the syscall request.

     * Since the protocol requires that gdb hands control back to us

     * using a "here are the results" F packet, we don't need to check

     * gdb_handlesig's return value (which is the signal to deliver if

     * execution was resumed via a continue packet).

     */

    gdb_handlesig(s->c_cpu, 0);

#else

    /* In this case wait to send the syscall packet until notification that

include/exec/gdbstub.h

+15 −0
Original line number Diff line number Diff line
@@ -48,6 +48,21 @@ int use_gdb_syscalls(void); 
void gdb_set_stop_cpu(CPUState *cpu);

void gdb_exit(CPUArchState *, int);

#ifdef CONFIG_USER_ONLY

/**

 * gdb_handlesig: yield control to gdb

 * @cpu: CPU

 * @sig: if non-zero, the signal number which caused us to stop

 *

 * This function yields control to gdb, when a user-mode-only target

 * needs to stop execution. If @sig is non-zero, then we will send a

 * stop packet to tell gdb that we have stopped because of this signal.

 *

 * This function will block (handling protocol requests from gdb)

 * until gdb tells us to continue target execution. When it does

 * return, the return value is a signal to deliver to the target,

 * or 0 if no signal should be delivered, ie the signal that caused

 * us to stop should be ignored.

 */

int gdb_handlesig(CPUState *, int);

void gdb_signalled(CPUArchState *, int);

void gdbserver_fork(CPUState *);