<div dir="ltr"><div>ping</div><div><br></div><div>(this still applies cleanly)<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Jan 19, 2024 at 12:57 PM Alexandra Hájková <<a href="mailto:ahajkova@redhat.com">ahajkova@redhat.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">packet_check_result currently returns an packet_result enum.<br>
If GDB will recieve an error in a format E.errtext, which<br>
is possible for some q packets, such errtext is lost if<br>
treated by packet_check_result.<br>
Introduce a new structure which bundles enum packet_result<br>
with possible error message or error code returned by<br>
the GDBserver.<br>
I plan to make more GDBserver response checking functions to use<br>
packet_check_result to make remote.c code more consistent.<br>
This will also allow to use E.errtext more in the future.<br>
<br>
There's no infrastructure to test this with a test case so<br>
I tested this by modifying store_registers_using_G function<br>
to get an error message:<br>
<br>
[remote] Sending packet: $GG00000000 ...<br>
<br>
gdbserver: Wrong sized register packet (expected 1792 bytes, got 1793)<br>
gdbserver: Invalid hex digit 71<br>
Killing process(es): 1104002<br>
[remote] Packet received: E01<br>
Could not write registers; remote failure reply '01'<br>
<br>
Reviewed-by: Thiago Jung Bauermann <<a href="mailto:thiago.bauermann@linaro.org" target="_blank">thiago.bauermann@linaro.org</a>><br>
---<br>
v2:<br>
- Added a unit test for packet_check_result.<br>
- Improved formatting and reorganised packet_result structure.<br>
- Renamed pkt_status to pkt_result and result to status varariablese<br>
where suitable.<br>
<br>
gdb/remote.c | 147 +++++++++++++++++++++++++++++++++++++++------------<br>
1 file changed, 113 insertions(+), 34 deletions(-)<br>
<br>
diff --git a/gdb/remote.c b/gdb/remote.c<br>
index dcc1a0d0639..8e51e588bce 100644<br>
--- a/gdb/remote.c<br>
+++ b/gdb/remote.c<br>
@@ -149,13 +149,46 @@ get_target_type_name (bool target_connected)<br>
/* Analyze a packet's return value and update the packet config<br>
accordingly. */<br>
<br>
-enum packet_result<br>
+enum packet_status<br>
{<br>
PACKET_ERROR,<br>
PACKET_OK,<br>
PACKET_UNKNOWN<br>
};<br>
<br>
+/* Keeps packet's return value. If packet's return value is PACKET_ERROR,<br>
+ err_msg contains an error message string from E.string or the number<br>
+ stored as a string from E.num. */<br>
+struct packet_result<br>
+{<br>
+ packet_result (enum packet_status status, std::string err_msg):<br>
+ m_status (status), m_err_msg (std::move (err_msg))<br>
+ {<br>
+ gdb_assert (status == PACKET_ERROR);<br>
+ }<br>
+<br>
+ explicit packet_result (enum packet_status status):<br>
+ m_status (status)<br>
+ {<br>
+ gdb_assert (status != PACKET_ERROR);<br>
+ }<br>
+<br>
+ enum packet_status status () const<br>
+ {<br>
+ return this->m_status;<br>
+ }<br>
+<br>
+ const char *err_msg () const<br>
+ {<br>
+ gdb_assert (this->m_status == PACKET_ERROR);<br>
+ return this->m_err_msg.c_str ();<br>
+ }<br>
+<br>
+private:<br>
+ enum packet_status m_status;<br>
+ std::string m_err_msg;<br>
+};<br>
+<br>
/* Enumeration of packets for a remote target. */<br>
<br>
enum {<br>
@@ -732,8 +765,8 @@ struct remote_features<br>
<br>
/* Check result value in BUF for packet WHICH_PACKET and update the packet's<br>
support configuration accordingly. */<br>
- packet_result packet_ok (const char *buf, const int which_packet);<br>
- packet_result packet_ok (const gdb::char_vector &buf, const int which_packet);<br>
+ packet_status packet_ok (const char *buf, const int which_packet);<br>
+ packet_status packet_ok (const gdb::char_vector &buf, const int which_packet);<br>
<br>
/* Configuration of a remote target's memory read packet. */<br>
memory_packet_config m_memory_read_packet_config;<br>
@@ -1254,7 +1287,7 @@ class remote_target : public process_stratum_target<br>
int unit_size,<br>
ULONGEST *xfered_len);<br>
<br>
- packet_result remote_send_printf (const char *format, ...)<br>
+ packet_status remote_send_printf (const char *format, ...)<br>
ATTRIBUTE_PRINTF (2, 3);<br>
<br>
target_xfer_status remote_flash_write (ULONGEST address,<br>
@@ -2418,7 +2451,10 @@ add_packet_config_cmd (const unsigned int which_packet, const char *name,<br>
}<br>
}<br>
<br>
-static enum packet_result<br>
+/* Check GDBserver's reply packet. Return packet_result<br>
+ structure which contains the packet_status enum<br>
+ and an error message for the PACKET_ERROR case. */<br>
+static packet_result<br>
packet_check_result (const char *buf)<br>
{<br>
if (buf[0] != '\0')<br>
@@ -2428,42 +2464,46 @@ packet_check_result (const char *buf)<br>
if (buf[0] == 'E'<br>
&& isxdigit (buf[1]) && isxdigit (buf[2])<br>
&& buf[3] == '\0')<br>
+ {<br>
/* "Enn" - definitely an error. */<br>
- return PACKET_ERROR;<br>
+ return { PACKET_ERROR, buf + 1 };<br>
+ }<br>
<br>
/* Always treat "E." as an error. This will be used for<br>
more verbose error messages, such as E.memtypes. */<br>
if (buf[0] == 'E' && buf[1] == '.')<br>
- return PACKET_ERROR;<br>
+ {<br>
+ return { PACKET_ERROR, buf + 2 };<br>
+ }<br>
<br>
/* The packet may or may not be OK. Just assume it is. */<br>
- return PACKET_OK;<br>
+ return packet_result ( PACKET_OK );<br>
}<br>
else<br>
+ {<br>
/* The stub does not support the packet. */<br>
- return PACKET_UNKNOWN;<br>
+ return packet_result ( PACKET_UNKNOWN );<br>
+ }<br>
}<br>
<br>
-static enum packet_result<br>
+static packet_result<br>
packet_check_result (const gdb::char_vector &buf)<br>
{<br>
return packet_check_result (buf.data ());<br>
}<br>
<br>
-packet_result<br>
+packet_status<br>
remote_features::packet_ok (const char *buf, const int which_packet)<br>
{<br>
packet_config *config = &m_protocol_packets[which_packet];<br>
packet_description *descr = &packets_descriptions[which_packet];<br>
<br>
- enum packet_result result;<br>
-<br>
if (config->detect != AUTO_BOOLEAN_TRUE<br>
&& config->support == PACKET_DISABLE)<br>
internal_error (_("packet_ok: attempt to use a disabled packet"));<br>
<br>
- result = packet_check_result (buf);<br>
- switch (result)<br>
+ packet_result result = packet_check_result (buf);<br>
+ switch (result.status ())<br>
{<br>
case PACKET_OK:<br>
case PACKET_ERROR:<br>
@@ -2498,10 +2538,10 @@ remote_features::packet_ok (const char *buf, const int which_packet)<br>
break;<br>
}<br>
<br>
- return result;<br>
+ return result.status ();<br>
}<br>
<br>
-packet_result<br>
+packet_status<br>
remote_features::packet_ok (const gdb::char_vector &buf, const int which_packet)<br>
{<br>
return packet_ok (buf.data (), which_packet);<br>
@@ -3000,7 +3040,7 @@ remote_target::set_syscall_catchpoint (int pid, bool needed, int any_count,<br>
gdb::array_view<const int> syscall_counts)<br>
{<br>
const char *catch_packet;<br>
- enum packet_result result;<br>
+ enum packet_status result;<br>
int n_sysno = 0;<br>
<br>
if (m_features.packet_support (PACKET_QCatchSyscalls) == PACKET_DISABLE)<br>
@@ -8791,9 +8831,10 @@ remote_target::send_g_packet ()<br>
xsnprintf (rs->buf.data (), get_remote_packet_size (), "g");<br>
putpkt (rs->buf);<br>
getpkt (&rs->buf);<br>
- if (packet_check_result (rs->buf) == PACKET_ERROR)<br>
+ packet_result result = packet_check_result (rs->buf);<br>
+ if (result.status () == PACKET_ERROR)<br>
error (_("Could not read registers; remote failure reply '%s'"),<br>
- rs->buf.data ());<br>
+ result.err_msg ());<br>
<br>
/* We can get out of synch in various cases. If the first character<br>
in the buffer is not a hex character, assume that has happened<br>
@@ -9099,9 +9140,10 @@ remote_target::store_registers_using_G (const struct regcache *regcache)<br>
bin2hex (regs, p, rsa->sizeof_g_packet);<br>
putpkt (rs->buf);<br>
getpkt (&rs->buf);<br>
- if (packet_check_result (rs->buf) == PACKET_ERROR)<br>
+ packet_result pkt_status = packet_check_result (rs->buf);<br>
+ if (pkt_status.status () == PACKET_ERROR)<br>
error (_("Could not write registers; remote failure reply '%s'"),<br>
- rs->buf.data ());<br>
+ pkt_status.err_msg ());<br>
}<br>
<br>
/* Store register REGNUM, or all registers if REGNUM == -1, from the contents<br>
@@ -9683,7 +9725,7 @@ remote_target::remote_read_bytes (CORE_ADDR memaddr,<br>
FORMAT and the remaining arguments, then gets the reply. Returns<br>
whether the packet was a success, a failure, or unknown. */<br>
<br>
-packet_result<br>
+packet_status<br>
remote_target::remote_send_printf (const char *format, ...)<br>
{<br>
struct remote_state *rs = get_remote_state ();<br>
@@ -9705,8 +9747,9 @@ remote_target::remote_send_printf (const char *format, ...)<br>
<br>
rs->buf[0] = '\0';<br>
getpkt (&rs->buf);<br>
+ packet_result pkt_status = packet_check_result (rs->buf);<br>
<br>
- return packet_check_result (rs->buf);<br>
+ return pkt_status.status ();<br>
}<br>
<br>
/* Flash writing can take quite some time. We'll set<br>
@@ -9718,7 +9761,7 @@ void<br>
remote_target::flash_erase (ULONGEST address, LONGEST length)<br>
{<br>
int addr_size = gdbarch_addr_bit (current_inferior ()->arch ()) / 8;<br>
- enum packet_result ret;<br>
+ enum packet_status ret;<br>
scoped_restore restore_timeout<br>
= make_scoped_restore (&remote_timeout, remote_flash_timeout);<br>
<br>
@@ -11308,7 +11351,7 @@ remote_target::verify_memory (const gdb_byte *data, CORE_ADDR lma, ULONGEST size<br>
if (target_has_execution ()<br>
&& m_features.packet_support (PACKET_qCRC) != PACKET_DISABLE)<br>
{<br>
- enum packet_result result;<br>
+ enum packet_status status;<br>
<br>
/* Make sure the remote is pointing at the right process. */<br>
set_general_process ();<br>
@@ -11324,10 +11367,10 @@ remote_target::verify_memory (const gdb_byte *data, CORE_ADDR lma, ULONGEST size<br>
<br>
getpkt (&rs->buf);<br>
<br>
- result = m_features.packet_ok (rs->buf, PACKET_qCRC);<br>
- if (result == PACKET_ERROR)<br>
+ status = m_features.packet_ok (rs->buf, PACKET_qCRC);<br>
+ if (status == PACKET_ERROR)<br>
return -1;<br>
- else if (result == PACKET_OK)<br>
+ else if (status == PACKET_OK)<br>
{<br>
for (target_crc = 0, tmp = &rs->buf[1]; *tmp; tmp++)<br>
target_crc = target_crc * 16 + fromhex (*tmp);<br>
@@ -12210,7 +12253,7 @@ remote_target::get_thread_local_address (ptid_t ptid, CORE_ADDR lm,<br>
struct remote_state *rs = get_remote_state ();<br>
char *p = rs->buf.data ();<br>
char *endp = p + get_remote_packet_size ();<br>
- enum packet_result result;<br>
+ enum packet_status result;<br>
<br>
strcpy (p, "qGetTLSAddr:");<br>
p += strlen (p);<br>
@@ -12256,7 +12299,7 @@ remote_target::get_tib_address (ptid_t ptid, CORE_ADDR *addr)<br>
struct remote_state *rs = get_remote_state ();<br>
char *p = rs->buf.data ();<br>
char *endp = p + get_remote_packet_size ();<br>
- enum packet_result result;<br>
+ enum packet_status result;<br>
<br>
strcpy (p, "qGetTIBAddr:");<br>
p += strlen (p);<br>
@@ -13821,7 +13864,7 @@ remote_target::get_trace_status (struct trace_status *ts)<br>
{<br>
/* Initialize it just to avoid a GCC false warning. */<br>
char *p = NULL;<br>
- enum packet_result result;<br>
+ enum packet_status result;<br>
struct remote_state *rs = get_remote_state ();<br>
<br>
if (m_features.packet_support (PACKET_qTStatus) == PACKET_DISABLE)<br>
@@ -14201,7 +14244,7 @@ remote_target::set_trace_buffer_size (LONGEST val)<br>
struct remote_state *rs = get_remote_state ();<br>
char *buf = rs->buf.data ();<br>
char *endbuf = buf + get_remote_packet_size ();<br>
- enum packet_result result;<br>
+ enum packet_status result;<br>
<br>
gdb_assert (val >= 0 || val == -1);<br>
buf += xsnprintf (buf, endbuf - buf, "QTBuffer:size:");<br>
@@ -15527,9 +15570,10 @@ remote_target::store_memtags (CORE_ADDR address, size_t len,<br>
<br>
putpkt (rs->buf);<br>
getpkt (&rs->buf);<br>
+ packet_result pkt_status = packet_check_result (rs->buf);<br>
<br>
/* Verify if the request was successful. */<br>
- return packet_check_result (rs->buf.data ()) == PACKET_OK;<br>
+ return pkt_status.status () == PACKET_OK;<br>
}<br>
<br>
/* Return true if remote target T is non-stop. */<br>
@@ -15626,6 +15670,39 @@ test_memory_tagging_functions ()<br>
expected.length ()) == 0);<br>
}<br>
<br>
+static void<br>
+test_packet_check_result ()<br>
+{<br>
+ std::string buf = "E01";<br>
+<br>
+ packet_result result = packet_check_result (buf.data ());<br>
+ SELF_CHECK (result.status () == PACKET_ERROR);<br>
+<br>
+ buf.assign("E1");<br>
+ result = packet_check_result (buf.data ());<br>
+ SELF_CHECK (result.status () == PACKET_OK);<br>
+<br>
+ buf.assign("E000");<br>
+ result = packet_check_result (buf.data ());<br>
+ SELF_CHECK (result.status () == PACKET_OK);<br>
+<br>
+ buf.assign("E.msg");<br>
+ result = packet_check_result (buf.data ());<br>
+ SELF_CHECK (result.status () == PACKET_ERROR);<br>
+<br>
+ buf.assign("E.");<br>
+ result = packet_check_result (buf.data ());<br>
+ SELF_CHECK (result.status () == PACKET_ERROR);<br>
+<br>
+ buf.assign("some response");<br>
+ result = packet_check_result (buf.data ());<br>
+ SELF_CHECK (result.status () == PACKET_OK);<br>
+<br>
+ buf.assign("");<br>
+ result = packet_check_result (buf.data ());<br>
+ SELF_CHECK (result.status () == PACKET_UNKNOWN);<br>
+}<br>
+<br>
} // namespace selftests<br>
#endif /* GDB_SELF_TEST */<br>
<br>
@@ -16125,5 +16202,7 @@ from the target."),<br>
#if GDB_SELF_TEST<br>
selftests::register_test ("remote_memory_tagging",<br>
selftests::test_memory_tagging_functions);<br>
+ selftests::register_test ("packet_check_result",<br>
+ selftests::test_packet_check_result);<br>
#endif<br>
}<br>
-- <br>
2.43.0<br>
<br>
</blockquote></div>