diff mbox series

[v9,04/24] gdbstub: use 0 ("any process") on packets with no PID

Message ID 20230804220032.295411-5-richard.henderson@linaro.org
State Superseded
Headers show
Series linux-user + tcg patch queue | expand

Commit Message

Richard Henderson Aug. 4, 2023, 10 p.m. UTC 
From: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>

Previously, qemu-user would always report PID 1 to GDB. This was changed
at dc14a7a6e9 (gdbstub: Report the actual qemu-user pid, 2023-06-30),
but read_thread_id() still considers GDB packets with "no PID" as "PID
1", which is not the qemu-user PID. Fix that by parsing "no PID" as "0",
which the GDB Remote Protocol defines as "any process".

Note that this should have no effect for system emulation as, in this
case, gdb_create_default_process() will assign PID 1 for the first
process and that is what the gdbstub uses for GDB requests with no PID,
or PID 0.

This issue was found with hexagon-lldb, which sends a "Hg" packet with
only the thread-id, but no process-id, leading to the invalid usage of
"PID 1" by qemu-hexagon and a subsequent "E22" reply.

Signed-off-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <78a3b06f6ab90a7ff8e73ae14a996eb27ec76c85.1690904195.git.quic_mathbern@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 gdbstub/gdbstub.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index ce8b42eb15..e74ecc78cc 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -537,7 +537,7 @@  static GDBThreadIdKind read_thread_id(const char *buf, const char **end_buf,
         /* Skip '.' */
         buf++;
     } else {
-        p = 1;
+        p = 0;
     }
 
     ret = qemu_strtoul(buf, &buf, 16, &t);