DavidSpickett created this revision.
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The type field is a signed integer.
(https://sourceware.org/gdb/current/onlinedocs/gdb/General-Query-Packets.html)
However it's not packed in the packet in the way
you might think. For example the type -1 should be:
qMemTags:<addr>,<len>:ffffffff
Instead of:
qMemTags:<addr>,<len>:-1
This change makes lldb-server's parsing more strict
and adds more tests to check that we handle negative types
correctly in lldb and lldb-server.
We only support one tag type value at this point,
for AArch64 MTE, which is positive. So this doesn't change
any of those interactions. It just brings us in line with GDB.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D104914
Files:
lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
lldb/test/API/tools/lldb-server/memory-tagging/TestGdbRemoteMemoryTagging.py
lldb/unittests/Process/gdb-remote/GDBRemoteCommunicationClientTest.cpp
Index: lldb/unittests/Process/gdb-remote/GDBRemoteCommunicationClientTest.cpp
===================================================================
--- lldb/unittests/Process/gdb-remote/GDBRemoteCommunicationClientTest.cpp
+++ lldb/unittests/Process/gdb-remote/GDBRemoteCommunicationClientTest.cpp
@@ -17,6 +17,7 @@
#include "llvm/Testing/Support/Error.h"
#include "gmock/gmock.h"
#include <future>
+#include <limits>
using namespace lldb_private::process_gdb_remote;
using namespace lldb_private;
@@ -468,19 +469,18 @@
static void
check_qmemtags(TestClient &client, MockServer &server, size_t read_len,
- const char *packet, llvm::StringRef response,
+ int32_t type, const char *packet, llvm::StringRef response,
llvm::Optional<std::vector<uint8_t>> expected_tag_data) {
- const auto &ReadMemoryTags = [&](size_t len, const char *packet,
- llvm::StringRef response) {
+ const auto &ReadMemoryTags = [&]() {
std::future<DataBufferSP> result = std::async(std::launch::async, [&] {
- return client.ReadMemoryTags(0xDEF0, read_len, 1);
+ return client.ReadMemoryTags(0xDEF0, read_len, type);
});
HandlePacket(server, packet, response);
return result.get();
};
- auto result = ReadMemoryTags(0, packet, response);
+ auto result = ReadMemoryTags();
if (expected_tag_data) {
ASSERT_TRUE(result);
llvm::ArrayRef<uint8_t> expected(*expected_tag_data);
@@ -493,40 +493,52 @@
TEST_F(GDBRemoteCommunicationClientTest, ReadMemoryTags) {
// Zero length reads are valid
- check_qmemtags(client, server, 0, "qMemTags:def0,0:1", "m",
+ check_qmemtags(client, server, 0, 1, "qMemTags:def0,0:1", "m",
std::vector<uint8_t>{});
+ // Type can be negative. Put into the packet as the raw bytes
+ // (as opposed to a literal -1)
+ check_qmemtags(client, server, 0, -1, "qMemTags:def0,0:ffffffff", "m",
+ std::vector<uint8_t>{});
+ check_qmemtags(client, server, 0, std::numeric_limits<int32_t>::min(),
+ "qMemTags:def0,0:80000000", "m", std::vector<uint8_t>{});
+ check_qmemtags(client, server, 0, std::numeric_limits<int32_t>::max(),
+ "qMemTags:def0,0:7fffffff", "m", std::vector<uint8_t>{});
+
// The client layer does not check the length of the received data.
// All we need is the "m" and for the decode to use all of the chars
- check_qmemtags(client, server, 32, "qMemTags:def0,20:1", "m09",
+ check_qmemtags(client, server, 32, 2, "qMemTags:def0,20:2", "m09",
std::vector<uint8_t>{0x9});
// Zero length response is fine as long as the "m" is present
- check_qmemtags(client, server, 0, "qMemTags:def0,0:1", "m",
+ check_qmemtags(client, server, 0, 0x34, "qMemTags:def0,0:34", "m",
std::vector<uint8_t>{});
// Normal responses
- check_qmemtags(client, server, 16, "qMemTags:def0,10:1", "m66",
+ check_qmemtags(client, server, 16, 1, "qMemTags:def0,10:1", "m66",
std::vector<uint8_t>{0x66});
- check_qmemtags(client, server, 32, "qMemTags:def0,20:1", "m0102",
+ check_qmemtags(client, server, 32, 1, "qMemTags:def0,20:1", "m0102",
std::vector<uint8_t>{0x1, 0x2});
// Empty response is an error
- check_qmemtags(client, server, 17, "qMemTags:def0,11:1", "", llvm::None);
+ check_qmemtags(client, server, 17, 1, "qMemTags:def0,11:1", "", llvm::None);
// Usual error response
- check_qmemtags(client, server, 17, "qMemTags:def0,11:1", "E01", llvm::None);
+ check_qmemtags(client, server, 17, 1, "qMemTags:def0,11:1", "E01",
+ llvm::None);
// Leading m missing
- check_qmemtags(client, server, 17, "qMemTags:def0,11:1", "01", llvm::None);
+ check_qmemtags(client, server, 17, 1, "qMemTags:def0,11:1", "01", llvm::None);
// Anything other than m is an error
- check_qmemtags(client, server, 17, "qMemTags:def0,11:1", "z01", llvm::None);
+ check_qmemtags(client, server, 17, 1, "qMemTags:def0,11:1", "z01",
+ llvm::None);
// Decoding tag data doesn't use all the chars in the packet
- check_qmemtags(client, server, 32, "qMemTags:def0,20:1", "m09zz", llvm::None);
+ check_qmemtags(client, server, 32, 1, "qMemTags:def0,20:1", "m09zz",
+ llvm::None);
// Data that is not hex bytes
- check_qmemtags(client, server, 32, "qMemTags:def0,20:1", "mhello",
+ check_qmemtags(client, server, 32, 1, "qMemTags:def0,20:1", "mhello",
llvm::None);
// Data is not a complete hex char
- check_qmemtags(client, server, 32, "qMemTags:def0,20:1", "m9", llvm::None);
+ check_qmemtags(client, server, 32, 1, "qMemTags:def0,20:1", "m9", llvm::None);
// Data has a trailing hex char
- check_qmemtags(client, server, 32, "qMemTags:def0,20:1", "m01020",
+ check_qmemtags(client, server, 32, 1, "qMemTags:def0,20:1", "m01020",
llvm::None);
}
Index: lldb/test/API/tools/lldb-server/memory-tagging/TestGdbRemoteMemoryTagging.py
===================================================================
--- lldb/test/API/tools/lldb-server/memory-tagging/TestGdbRemoteMemoryTagging.py
+++ lldb/test/API/tools/lldb-server/memory-tagging/TestGdbRemoteMemoryTagging.py
@@ -86,13 +86,20 @@
self.check_qmemtags_response("{:x},10:".format(buf_address), "E03")
# Types we don't support
self.check_qmemtags_response("{:x},10:FF".format(buf_address), "E01")
+ # Types can also be negative, so this is E01 for not supported,
+ # instead of E03 for invalid formatting.
+ self.check_qmemtags_response("{:x},10:FFFFFFFF".format(buf_address), "E01")
# (even if the length of the read is zero)
self.check_qmemtags_response("{:x},0:FF".format(buf_address), "E01")
- self.check_qmemtags_response("{:x},10:-1".format(buf_address), "E01")
- self.check_qmemtags_response("{:x},10:+20".format(buf_address), "E01")
# Invalid type format
self.check_qmemtags_response("{:x},10:cat".format(buf_address), "E03")
self.check_qmemtags_response("{:x},10:?11".format(buf_address), "E03")
+ # Type is signed but in packet as raw bytes, no +/-.
+ self.check_qmemtags_response("{:x},10:-1".format(buf_address), "E03")
+ self.check_qmemtags_response("{:x},10:+20".format(buf_address), "E03")
+ # We do use a uint64_t for unpacking but that's just an implementation
+ # detail. Any value > 32 bit is invalid.
+ self.check_qmemtags_response("{:x},10:123412341".format(buf_address), "E03")
# Valid packets
Index: lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
===================================================================
--- lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
+++ lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
@@ -3462,14 +3462,27 @@
if (packet.GetBytesLeft() < 1 || packet.GetChar() != ':')
return SendIllFormedResponse(packet, invalid_type_err);
- int32_t type =
- packet.GetS32(std::numeric_limits<int32_t>::max(), /*base=*/16);
- if (type == std::numeric_limits<int32_t>::max() ||
+ // Type is a signed integer but packed into the packet as its raw bytes.
+ // However, our GetU64 uses strtoull which allows +/-. We do not want this.
+ const char *first_type_char = packet.Peek();
+ if (first_type_char && (*first_type_char == '+' || *first_type_char == '-'))
+ return SendIllFormedResponse(packet, invalid_type_err);
+
+ // Extract type as unsigned then cast to signed.
+ // Using a uint64_t here so that we have some value outside of the 32 bit
+ // range to use as the invalid return value.
+ uint64_t raw_type =
+ packet.GetU64(std::numeric_limits<uint64_t>::max(), /*base=*/16);
+
+ if (raw_type == std::numeric_limits<uint64_t>::max() ||
+ // Make sure the cast below would be valid
+ raw_type > std::numeric_limits<uint32_t>::max() ||
// To catch inputs like "123aardvark" that will parse but clearly aren't
// valid in this case.
packet.GetBytesLeft()) {
return SendIllFormedResponse(packet, invalid_type_err);
}
+ int32_t type = static_cast<int32_t>(raw_type);
StreamGDBRemote response;
std::vector<uint8_t> tags;
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