[Lldb-commits] [lldb] [lldb] Optimized lldb-server memory usage (PR #100666)

[Dmitry Vasilyev via lldb-commits]

https://github.com/slydiman updated https://github.com/llvm/llvm-project/pull/100666

>From 0e451f16b91bab2bc2cd1375eb02e4fe71998790 Mon Sep 17 00:00:00 2001
From: Dmitry Vasilyev <dvassiliev at accesssoftek.com>
Date: Fri, 26 Jul 2024 02:40:49 +0400
Subject: [PATCH 1/3] [lldb] Optimized lldb-server memory usage

MAX_PATH is definitely larger than 6 bytes we are expecting for this message, and could be rather large depending on the target OS (4K for some Linux OSs).

Since the buffer gets allocated on the stack we better be conservative and allocate what we actually need.
---
 .../Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp      | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
index 187370eb36cae..b961c0e42469a 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
@@ -1145,7 +1145,8 @@ Status GDBRemoteCommunication::StartDebugserverProcess(
       if (socket_pipe.CanWrite())
         socket_pipe.CloseWriteFileDescriptor();
       if (socket_pipe.CanRead()) {
-        char port_cstr[PATH_MAX] = {0};
+        // The port number may be "1024\0".."65535\0".
+        char port_cstr[6] = {0};
         port_cstr[0] = '\0';
         size_t num_bytes = sizeof(port_cstr);
         // Read port from pipe with 10 second timeout.

>From 4562af94a7417575fec100e5bbe745b21870e6fc Mon Sep 17 00:00:00 2001
From: Dmitry Vasilyev <dvassiliev at accesssoftek.com>
Date: Fri, 26 Jul 2024 11:55:08 +0400
Subject: [PATCH 2/3] Removed the redundant line.

---
 .../source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
index b961c0e42469a..07aa8209ca4ba 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
@@ -1147,7 +1147,6 @@ Status GDBRemoteCommunication::StartDebugserverProcess(
       if (socket_pipe.CanRead()) {
         // The port number may be "1024\0".."65535\0".
         char port_cstr[6] = {0};
-        port_cstr[0] = '\0';
         size_t num_bytes = sizeof(port_cstr);
         // Read port from pipe with 10 second timeout.
         error = socket_pipe.ReadWithTimeout(

>From ac300300b7e5c7a0cf1882d0a81efc24e587125c Mon Sep 17 00:00:00 2001
From: Dmitry Vassiliev <dvassiliev at accesssoftek.com>
Date: Fri, 26 Jul 2024 18:53:20 +0400
Subject: [PATCH 3/3] Updated the comment.

---
 .../Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp       | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
index 07aa8209ca4ba..5d0a3e31d0437 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
@@ -1145,7 +1145,7 @@ Status GDBRemoteCommunication::StartDebugserverProcess(
       if (socket_pipe.CanWrite())
         socket_pipe.CloseWriteFileDescriptor();
       if (socket_pipe.CanRead()) {
-        // The port number may be "1024\0".."65535\0".
+        // The port number may be up to "65535\0".
         char port_cstr[6] = {0};
         size_t num_bytes = sizeof(port_cstr);
         // Read port from pipe with 10 second timeout.