base: increase the GDB buffer size dynamically
The size was not large enough for the 'G' packet on aarch64, which the
client sends to set registers.
This would lead to the stub not to be able to find the end of the input
packet and keep waiting forever.
Change-Id: Icb149f15a6c769371ebcb6ec5fbebc6170c31fc6
Reviewed-on: https://gem5-review.googlesource.com/c/14497
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
diff --git a/src/base/remote_gdb.cc b/src/base/remote_gdb.cc
index 37ecef9..2c54f5b 100644
--- a/src/base/remote_gdb.cc
+++ b/src/base/remote_gdb.cc
@@ -152,8 +152,6 @@
static const char GDBGoodP = '+';
static const char GDBBadP = '-';
-static const int GDBPacketBufLen = 1024;
-
vector<BaseRemoteGDB *> debuggers;
class HardBreakpoint : public PCEvent
@@ -441,20 +439,19 @@
regCachePtr = gdbRegs();
regCachePtr->getRegs(tc);
- char data[GDBPacketBufLen + 1];
GdbCommand::Context cmdCtx;
cmdCtx.type = type;
- cmdCtx.data = &data[1];
+ std::vector<char> data;
for (;;) {
try {
- size_t datalen = recv(data, sizeof(data));
- if (datalen < 1)
+ recv(data);
+ if (data.size() == 1)
throw BadClient();
-
- data[datalen] = 0; // Sentinel
cmdCtx.cmd_byte = data[0];
- cmdCtx.len = datalen - 1;
+ cmdCtx.data = data.data() + 1;
+ // One for sentinel, one for cmd_byte.
+ cmdCtx.len = data.size() - 2;
auto cmdIt = command_map.find(cmdCtx.cmd_byte);
if (cmdIt == command_map.end()) {
@@ -521,41 +518,31 @@
}
// Receive a packet from gdb
-int
-BaseRemoteGDB::recv(char *bp, int maxlen)
+void
+BaseRemoteGDB::recv(std::vector<char>& bp)
{
- char *p;
uint8_t c;
int csum;
- int len;
+ bp.resize(0);
do {
- p = bp;
- csum = len = 0;
+ csum = 0;
// Find the beginning of a packet
while ((c = getbyte()) != GDBStart);
// Read until you find the end of the data in the packet, and keep
// track of the check sum.
- while (len < maxlen) {
+ while (true) {
c = getbyte();
if (c == GDBEnd)
break;
c &= 0x7f;
csum += c;
- *p++ = c;
- len++;
+ bp.push_back(c);
}
- // Mask the check sum, and terminate the command string.
+ // Mask the check sum.
csum &= 0xff;
- *p = '\0';
-
- // If the command was too long, report an error.
- if (len >= maxlen) {
- putbyte(GDBBadP);
- continue;
- }
// Bring in the checksum. If the check sum matches, csum will be 0.
csum -= digit2i(getbyte()) * 16;
@@ -566,21 +553,20 @@
// Report that the packet was received correctly
putbyte(GDBGoodP);
// Sequence present?
- if (bp[2] == ':') {
+ if (bp.size() > 2 && bp[2] == ':') {
putbyte(bp[0]);
putbyte(bp[1]);
- len -= 3;
- memcpy(bp, bp+3, len);
+ auto begin = std::begin(bp);
+ bp.erase(begin, std::next(begin, 3));
}
break;
}
// Otherwise, report that there was a mistake.
putbyte(GDBBadP);
} while (1);
-
- DPRINTF(GDBRecv, "recv: %s\n", bp);
-
- return len;
+ // Sentinel.
+ bp.push_back('\0');
+ DPRINTF(GDBRecv, "recv: %s\n", bp.data());
}
// Send a packet to gdb
diff --git a/src/base/remote_gdb.hh b/src/base/remote_gdb.hh
index 27b4ab4..82a1e15 100644
--- a/src/base/remote_gdb.hh
+++ b/src/base/remote_gdb.hh
@@ -171,7 +171,7 @@
uint8_t getbyte();
void putbyte(uint8_t b);
- int recv(char *data, int len);
+ void recv(std::vector<char> &bp);
void send(const char *data);
/*
