Commit f96900de authored by Leena Miettinen's avatar Leena Miettinen
Browse files

Doc: debugger cannot attach to running process on Linux

Reviewed-by: hjk
parent 9f7ee38e
......@@ -10938,18 +10938,6 @@
paths may fail. For example, remounting parts of a file system
using the --bind mount option.
\o You must use a workaround to use the DYLD_IMAGE_SUFFIX option in the
\gui Projects tab on Mac OS X Snow Leopard. For more information on
the issue, see
\l{http://wimleers.com/blog/dyld-image-suffix-causing-havoc-on-mac-os-x-snow-leopard}{DYLD_IMAGE_SUFFIX causing havoc on Mac OS X Snow Leopard}.
To use the option, enter the following commands in the Terminal
application:
\code
sudo mv /usr/lib/libSystem.B_debug.dylib /usr/lib/libSystem.B_debug.dylib.backup
sudo cp /usr/lib/libSystem.B.dylib /usr/lib/libSystem.B_debug.dylib.backup
\endcode
\endlist
\section1 Qt Quick Designer Issues
......@@ -11348,7 +11336,7 @@
\endlist
\section1 Directly Displaying Pointer Variable Members
\section1 Pointer Variable Members Are Not Displayed Directly
When you use the \gui {Locals and Watchers} view to inspect a pointer
variable and expand the variable tree item, another tree item level
......@@ -11374,6 +11362,37 @@
helpers operate on wrong data and come to wrong conclusions. Most likely,
they find garbage and declare the variable to be <not in scope>.
\section1 Application Crashes when Debugging on Mac OS X Snow Leopard
You must use a workaround to use the DYLD_IMAGE_SUFFIX option in the
\gui Projects tab on Mac OS X Snow Leopard. For more information on the
issue, see
\l{http://wimleers.com/blog/dyld-image-suffix-causing-havoc-on-mac-os-x-snow-leopard}{DYLD_IMAGE_SUFFIX causing havoc on Mac OS X Snow Leopard}.
To use the option, enter the following commands in the Terminal
application:
\code
sudo mv /usr/lib/libSystem.B_debug.dylib /usr/lib/libSystem.B_debug.dylib.backup
sudo cp /usr/lib/libSystem.B.dylib /usr/lib/libSystem.B_debug.dylib.backup
\endcode
\section1 Debugger Cannot Attach to Running Process on Linux
GDB uses \c ptrace to attach to running processes. Some Linux distributions
do not allow this, which stops all attempts to either directly attach to an
existing process or use the \gui {Run in terminal} option in Qt Creator.
The reasons for this are described in
\l{https://wiki.ubuntu.com/SecurityTeam/Roadmap/KernelHardening#ptrace%20Protection}{KernelHardening}.
However, the usefulness of this security measure seems dubious,
because this feature can be easily disabled. With root permissions, you can
disable the feature immediately by writing \c{0} into
\c{/proc/sys/kernel/yama/ptrace_scope}. Even if you do not have elevated
permissions, you can disable the feature later by adding a library that
calls \c{prctl(0x59616d61, getppid(), 0, 0, 0);}, such as the one in
\c{$QTCREATORDIR/lib/libptracepreload.so} to the LD_PRELOAD environment.
*/
......@@ -11381,7 +11400,7 @@
\contentspage index.html
\previouspage creator-debugging-qml.html
\page creator-analyzer.html
\nextpage creator-maemo-emulator.html
\nextpage creator-troubleshooting-debugging.html
\title Detecting Memory Leaks
......
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