From: "Alexandra Hájková" <ahajkova@redhat.com>
To: gdb-patches@sourceware.org
Subject: [PATCH v2] remote.c: Make packet_check_result return a structure
Date: Sun, 7 Jan 2024 15:56:51 +0100 [thread overview]
Message-ID: <20240107150213.888213-1-ahajkova@redhat.com> (raw)
packet_check_result currently returns an packet_result enum.
If GDB will recieve an error in a format E.errtext, which
is possible for some q packets, such errtext is lost if
treated by packet_check_result.
Introduce a new structure which bundles enum packet_result
with possible error message or error code returned by
the GDBserver.
I plan to make more GDBserver response checking functions to use
packet_check_result to make remote.c code more consistent.
This will also allow to use E.errtext more in the future.
There's no infrastructure to test this with a test case so
I tested this by modifying store_registers_using_G function
to get an error message:
[remote] Sending packet: $GG00000000 ...
gdbserver: Wrong sized register packet (expected 1792 bytes, got 1793)
gdbserver: Invalid hex digit 71
Killing process(es): 1104002
[remote] Packet received: E01
Could not write registers; remote failure reply '01'
Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
---
v2:
- Added a unit test for packet_check_result.
- Improved formatting and reorganised packet_result structure.
- Renamed pkt_status to pkt_result and result to status varariablese
where suitable.
gdb/remote.c | 147 +++++++++++++++++++++++++++++++++++++++------------
1 file changed, 113 insertions(+), 34 deletions(-)
diff --git a/gdb/remote.c b/gdb/remote.c
index dcc1a0d0639..8e51e588bce 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -149,13 +149,46 @@ get_target_type_name (bool target_connected)
/* Analyze a packet's return value and update the packet config
accordingly. */
-enum packet_result
+enum packet_status
{
PACKET_ERROR,
PACKET_OK,
PACKET_UNKNOWN
};
+/* Keeps packet's return value. If packet's return value is PACKET_ERROR,
+ err_msg contains an error message string from E.string or the number
+ stored as a string from E.num. */
+struct packet_result
+{
+ packet_result (enum packet_status status, std::string err_msg):
+ m_status (status), m_err_msg (std::move (err_msg))
+ {
+ gdb_assert (status == PACKET_ERROR);
+ }
+
+ explicit packet_result (enum packet_status status):
+ m_status (status)
+ {
+ gdb_assert (status != PACKET_ERROR);
+ }
+
+ enum packet_status status () const
+ {
+ return this->m_status;
+ }
+
+ const char *err_msg () const
+ {
+ gdb_assert (this->m_status == PACKET_ERROR);
+ return this->m_err_msg.c_str ();
+ }
+
+private:
+ enum packet_status m_status;
+ std::string m_err_msg;
+};
+
/* Enumeration of packets for a remote target. */
enum {
@@ -732,8 +765,8 @@ struct remote_features
/* Check result value in BUF for packet WHICH_PACKET and update the packet's
support configuration accordingly. */
- packet_result packet_ok (const char *buf, const int which_packet);
- packet_result packet_ok (const gdb::char_vector &buf, const int which_packet);
+ packet_status packet_ok (const char *buf, const int which_packet);
+ packet_status packet_ok (const gdb::char_vector &buf, const int which_packet);
/* Configuration of a remote target's memory read packet. */
memory_packet_config m_memory_read_packet_config;
@@ -1254,7 +1287,7 @@ class remote_target : public process_stratum_target
int unit_size,
ULONGEST *xfered_len);
- packet_result remote_send_printf (const char *format, ...)
+ packet_status remote_send_printf (const char *format, ...)
ATTRIBUTE_PRINTF (2, 3);
target_xfer_status remote_flash_write (ULONGEST address,
@@ -2418,7 +2451,10 @@ add_packet_config_cmd (const unsigned int which_packet, const char *name,
}
}
-static enum packet_result
+/* Check GDBserver's reply packet. Return packet_result
+ structure which contains the packet_status enum
+ and an error message for the PACKET_ERROR case. */
+static packet_result
packet_check_result (const char *buf)
{
if (buf[0] != '\0')
@@ -2428,42 +2464,46 @@ packet_check_result (const char *buf)
if (buf[0] == 'E'
&& isxdigit (buf[1]) && isxdigit (buf[2])
&& buf[3] == '\0')
+ {
/* "Enn" - definitely an error. */
- return PACKET_ERROR;
+ return { PACKET_ERROR, buf + 1 };
+ }
/* Always treat "E." as an error. This will be used for
more verbose error messages, such as E.memtypes. */
if (buf[0] == 'E' && buf[1] == '.')
- return PACKET_ERROR;
+ {
+ return { PACKET_ERROR, buf + 2 };
+ }
/* The packet may or may not be OK. Just assume it is. */
- return PACKET_OK;
+ return packet_result ( PACKET_OK );
}
else
+ {
/* The stub does not support the packet. */
- return PACKET_UNKNOWN;
+ return packet_result ( PACKET_UNKNOWN );
+ }
}
-static enum packet_result
+static packet_result
packet_check_result (const gdb::char_vector &buf)
{
return packet_check_result (buf.data ());
}
-packet_result
+packet_status
remote_features::packet_ok (const char *buf, const int which_packet)
{
packet_config *config = &m_protocol_packets[which_packet];
packet_description *descr = &packets_descriptions[which_packet];
- enum packet_result result;
-
if (config->detect != AUTO_BOOLEAN_TRUE
&& config->support == PACKET_DISABLE)
internal_error (_("packet_ok: attempt to use a disabled packet"));
- result = packet_check_result (buf);
- switch (result)
+ packet_result result = packet_check_result (buf);
+ switch (result.status ())
{
case PACKET_OK:
case PACKET_ERROR:
@@ -2498,10 +2538,10 @@ remote_features::packet_ok (const char *buf, const int which_packet)
break;
}
- return result;
+ return result.status ();
}
-packet_result
+packet_status
remote_features::packet_ok (const gdb::char_vector &buf, const int which_packet)
{
return packet_ok (buf.data (), which_packet);
@@ -3000,7 +3040,7 @@ remote_target::set_syscall_catchpoint (int pid, bool needed, int any_count,
gdb::array_view<const int> syscall_counts)
{
const char *catch_packet;
- enum packet_result result;
+ enum packet_status result;
int n_sysno = 0;
if (m_features.packet_support (PACKET_QCatchSyscalls) == PACKET_DISABLE)
@@ -8791,9 +8831,10 @@ remote_target::send_g_packet ()
xsnprintf (rs->buf.data (), get_remote_packet_size (), "g");
putpkt (rs->buf);
getpkt (&rs->buf);
- if (packet_check_result (rs->buf) == PACKET_ERROR)
+ packet_result result = packet_check_result (rs->buf);
+ if (result.status () == PACKET_ERROR)
error (_("Could not read registers; remote failure reply '%s'"),
- rs->buf.data ());
+ result.err_msg ());
/* We can get out of synch in various cases. If the first character
in the buffer is not a hex character, assume that has happened
@@ -9099,9 +9140,10 @@ remote_target::store_registers_using_G (const struct regcache *regcache)
bin2hex (regs, p, rsa->sizeof_g_packet);
putpkt (rs->buf);
getpkt (&rs->buf);
- if (packet_check_result (rs->buf) == PACKET_ERROR)
+ packet_result pkt_status = packet_check_result (rs->buf);
+ if (pkt_status.status () == PACKET_ERROR)
error (_("Could not write registers; remote failure reply '%s'"),
- rs->buf.data ());
+ pkt_status.err_msg ());
}
/* Store register REGNUM, or all registers if REGNUM == -1, from the contents
@@ -9683,7 +9725,7 @@ remote_target::remote_read_bytes (CORE_ADDR memaddr,
FORMAT and the remaining arguments, then gets the reply. Returns
whether the packet was a success, a failure, or unknown. */
-packet_result
+packet_status
remote_target::remote_send_printf (const char *format, ...)
{
struct remote_state *rs = get_remote_state ();
@@ -9705,8 +9747,9 @@ remote_target::remote_send_printf (const char *format, ...)
rs->buf[0] = '\0';
getpkt (&rs->buf);
+ packet_result pkt_status = packet_check_result (rs->buf);
- return packet_check_result (rs->buf);
+ return pkt_status.status ();
}
/* Flash writing can take quite some time. We'll set
@@ -9718,7 +9761,7 @@ void
remote_target::flash_erase (ULONGEST address, LONGEST length)
{
int addr_size = gdbarch_addr_bit (current_inferior ()->arch ()) / 8;
- enum packet_result ret;
+ enum packet_status ret;
scoped_restore restore_timeout
= make_scoped_restore (&remote_timeout, remote_flash_timeout);
@@ -11308,7 +11351,7 @@ remote_target::verify_memory (const gdb_byte *data, CORE_ADDR lma, ULONGEST size
if (target_has_execution ()
&& m_features.packet_support (PACKET_qCRC) != PACKET_DISABLE)
{
- enum packet_result result;
+ enum packet_status status;
/* Make sure the remote is pointing at the right process. */
set_general_process ();
@@ -11324,10 +11367,10 @@ remote_target::verify_memory (const gdb_byte *data, CORE_ADDR lma, ULONGEST size
getpkt (&rs->buf);
- result = m_features.packet_ok (rs->buf, PACKET_qCRC);
- if (result == PACKET_ERROR)
+ status = m_features.packet_ok (rs->buf, PACKET_qCRC);
+ if (status == PACKET_ERROR)
return -1;
- else if (result == PACKET_OK)
+ else if (status == PACKET_OK)
{
for (target_crc = 0, tmp = &rs->buf[1]; *tmp; tmp++)
target_crc = target_crc * 16 + fromhex (*tmp);
@@ -12210,7 +12253,7 @@ remote_target::get_thread_local_address (ptid_t ptid, CORE_ADDR lm,
struct remote_state *rs = get_remote_state ();
char *p = rs->buf.data ();
char *endp = p + get_remote_packet_size ();
- enum packet_result result;
+ enum packet_status result;
strcpy (p, "qGetTLSAddr:");
p += strlen (p);
@@ -12256,7 +12299,7 @@ remote_target::get_tib_address (ptid_t ptid, CORE_ADDR *addr)
struct remote_state *rs = get_remote_state ();
char *p = rs->buf.data ();
char *endp = p + get_remote_packet_size ();
- enum packet_result result;
+ enum packet_status result;
strcpy (p, "qGetTIBAddr:");
p += strlen (p);
@@ -13821,7 +13864,7 @@ remote_target::get_trace_status (struct trace_status *ts)
{
/* Initialize it just to avoid a GCC false warning. */
char *p = NULL;
- enum packet_result result;
+ enum packet_status result;
struct remote_state *rs = get_remote_state ();
if (m_features.packet_support (PACKET_qTStatus) == PACKET_DISABLE)
@@ -14201,7 +14244,7 @@ remote_target::set_trace_buffer_size (LONGEST val)
struct remote_state *rs = get_remote_state ();
char *buf = rs->buf.data ();
char *endbuf = buf + get_remote_packet_size ();
- enum packet_result result;
+ enum packet_status result;
gdb_assert (val >= 0 || val == -1);
buf += xsnprintf (buf, endbuf - buf, "QTBuffer:size:");
@@ -15527,9 +15570,10 @@ remote_target::store_memtags (CORE_ADDR address, size_t len,
putpkt (rs->buf);
getpkt (&rs->buf);
+ packet_result pkt_status = packet_check_result (rs->buf);
/* Verify if the request was successful. */
- return packet_check_result (rs->buf.data ()) == PACKET_OK;
+ return pkt_status.status () == PACKET_OK;
}
/* Return true if remote target T is non-stop. */
@@ -15626,6 +15670,39 @@ test_memory_tagging_functions ()
expected.length ()) == 0);
}
+static void
+test_packet_check_result ()
+{
+ std::string buf = "E01";
+
+ packet_result result = packet_check_result (buf.data ());
+ SELF_CHECK (result.status () == PACKET_ERROR);
+
+ buf.assign("E1");
+ result = packet_check_result (buf.data ());
+ SELF_CHECK (result.status () == PACKET_OK);
+
+ buf.assign("E000");
+ result = packet_check_result (buf.data ());
+ SELF_CHECK (result.status () == PACKET_OK);
+
+ buf.assign("E.msg");
+ result = packet_check_result (buf.data ());
+ SELF_CHECK (result.status () == PACKET_ERROR);
+
+ buf.assign("E.");
+ result = packet_check_result (buf.data ());
+ SELF_CHECK (result.status () == PACKET_ERROR);
+
+ buf.assign("some response");
+ result = packet_check_result (buf.data ());
+ SELF_CHECK (result.status () == PACKET_OK);
+
+ buf.assign("");
+ result = packet_check_result (buf.data ());
+ SELF_CHECK (result.status () == PACKET_UNKNOWN);
+}
+
} // namespace selftests
#endif /* GDB_SELF_TEST */
@@ -16125,5 +16202,7 @@ from the target."),
#if GDB_SELF_TEST
selftests::register_test ("remote_memory_tagging",
selftests::test_memory_tagging_functions);
+ selftests::register_test ("packet_check_result",
+ selftests::test_packet_check_result);
#endif
}
--
2.43.0
next reply other threads:[~2024-01-07 15:02 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-07 14:56 Alexandra Hájková [this message]
2024-01-09 19:01 ` Tom Tromey
2024-01-19 11:56 [PATCH v2 0/6] Add vDefaultInferiorFd feature Alexandra Hájková
2024-01-19 11:56 ` [PATCH v2] remote.c: Make packet_check_result return a structure Alexandra Hájková
2024-02-22 14:37 ` Alexandra Petlanova Hajkova
2024-02-23 16:19 ` Tom Tromey
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