[Lldb-commits] [PATCH] D28808: Fix a bug where lldb does not respect the packet size.
Hafiz Abid Qadeer via Phabricator via lldb-commits
lldb-commits at lists.llvm.org
Sun Jan 22 10:13:57 PST 2017
abidh updated this revision to Diff 85280.
abidh added a comment.
Use GetLogIfAnyCategoryIsSet as advised in comments.
https://reviews.llvm.org/D28808
Files:
source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
Index: source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
===================================================================
--- source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -2729,16 +2729,19 @@
size_t ProcessGDBRemote::DoReadMemory(addr_t addr, void *buf, size_t size,
Error &error) {
GetMaxMemorySize();
- if (size > m_max_memory_size) {
+ bool binary_memory_read = m_gdb_comm.GetxPacketSupported();
+ // M and m packets take 2 bytes for 1 byte of memory
+ size_t max_memory_size =
+ binary_memory_read ? m_max_memory_size : m_max_memory_size / 2;
+ if (size > max_memory_size) {
// Keep memory read sizes down to a sane limit. This function will be
// called multiple times in order to complete the task by
// lldb_private::Process so it is ok to do this.
- size = m_max_memory_size;
+ size = max_memory_size;
}
char packet[64];
int packet_len;
- bool binary_memory_read = m_gdb_comm.GetxPacketSupported();
packet_len = ::snprintf(packet, sizeof(packet), "%c%" PRIx64 ",%" PRIx64,
binary_memory_read ? 'x' : 'm', (uint64_t)addr,
(uint64_t)size);
@@ -2785,11 +2788,13 @@
size_t ProcessGDBRemote::DoWriteMemory(addr_t addr, const void *buf,
size_t size, Error &error) {
GetMaxMemorySize();
- if (size > m_max_memory_size) {
+ // M and m packets take 2 bytes for 1 byte of memory
+ size_t max_memory_size = m_max_memory_size / 2;
+ if (size > max_memory_size) {
// Keep memory read sizes down to a sane limit. This function will be
// called multiple times in order to complete the task by
// lldb_private::Process so it is ok to do this.
- size = m_max_memory_size;
+ size = max_memory_size;
}
StreamString packet;
@@ -3988,6 +3993,21 @@
stub_max_size = reasonable_largeish_default;
}
+ // Memory packet have other overheads too like Maddr,size:#NN
+ // Instead of calculating the bytes taken by size and addr every
+ // time, we take a maximum guess here.
+ if (stub_max_size > 70)
+ stub_max_size -= 32 + 32 + 6;
+ else {
+ // In unlikely scenario that max packet size is less then 70, we will
+ // hope that data being written is small enough to fit.
+ Log *log(ProcessGDBRemoteLog::GetLogIfAnyCategoryIsSet(
+ GDBR_LOG_COMM | GDBR_LOG_MEMORY));
+ if (log)
+ log->Warning("Packet size is too small. "
+ "LLDB may face problems while writing memory");
+ }
+
m_max_memory_size = stub_max_size;
} else {
m_max_memory_size = conservative_default;
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