diff options
| author | Ingo Molnar <mingo@kernel.org> | 2017-09-04 11:01:18 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-09-04 11:01:18 +0200 |
| commit | edc2988c548db05e33b921fed15821010bc74895 (patch) | |
| tree | b35860428acea35e5866d4cf007519ed943a85de /Documentation/dev-tools | |
| parent | d82fed75294229abc9d757f08a4817febae6c4f4 (diff) | |
| parent | 81a84ad3cb5711cec79f4dd53a4ce026b092c432 (diff) | |
Merge branch 'linus' into locking/core, to fix up conflicts
Conflicts:
mm/page_alloc.c
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'Documentation/dev-tools')
| -rw-r--r-- | Documentation/dev-tools/gdb-kernel-debugging.rst | 6 | ||||
| -rw-r--r-- | Documentation/dev-tools/kgdb.rst | 11 |
2 files changed, 14 insertions, 3 deletions
diff --git a/Documentation/dev-tools/gdb-kernel-debugging.rst b/Documentation/dev-tools/gdb-kernel-debugging.rst index 5e93c9bc6619..19df79286f00 100644 --- a/Documentation/dev-tools/gdb-kernel-debugging.rst +++ b/Documentation/dev-tools/gdb-kernel-debugging.rst @@ -31,11 +31,13 @@ Setup CONFIG_DEBUG_INFO_REDUCED off. If your architecture supports CONFIG_FRAME_POINTER, keep it enabled. -- Install that kernel on the guest. +- Install that kernel on the guest, turn off KASLR if necessary by adding + "nokaslr" to the kernel command line. Alternatively, QEMU allows to boot the kernel directly using -kernel, -append, -initrd command line switches. This is generally only useful if you do not depend on modules. See QEMU documentation for more details on - this mode. + this mode. In this case, you should build the kernel with + CONFIG_RANDOMIZE_BASE disabled if the architecture supports KASLR. - Enable the gdb stub of QEMU/KVM, either diff --git a/Documentation/dev-tools/kgdb.rst b/Documentation/dev-tools/kgdb.rst index 75273203a35a..d38be58f872a 100644 --- a/Documentation/dev-tools/kgdb.rst +++ b/Documentation/dev-tools/kgdb.rst @@ -348,6 +348,15 @@ default behavior is always set to 0. - ``echo 1 > /sys/module/debug_core/parameters/kgdbreboot`` - Enter the debugger on reboot notify. +Kernel parameter: ``nokaslr`` +----------------------------- + +If the architecture that you are using enable KASLR by default, +you should consider turning it off. KASLR randomizes the +virtual address where the kernel image is mapped and confuse +gdb which resolve kernel symbol address from symbol table +of vmlinux. + Using kdb ========= @@ -358,7 +367,7 @@ This is a quick example of how to use kdb. 1. Configure kgdboc at boot using kernel parameters:: - console=ttyS0,115200 kgdboc=ttyS0,115200 + console=ttyS0,115200 kgdboc=ttyS0,115200 nokaslr OR |