27f8a4e806
This commit adds a framework to abstract runtime code patching. Components in the new framework can provide functions for either patching a named function or a function pointer. The later functionality is not being used but may provide a way to allow memory hooks when dlopen functionality is disabled. This commit adds two different flavors of code patching. The first is provided by the overwrite component. This component overwrites the first several instructions of the target function with code to jump to the provided hook function. The hook is expected to provide the full functionality of the hooked function. The linux patcher component is based on the memory hooks in ucx. It only works on linux and operates by overwriting function pointers in the symbol table. In this case the hook is free to call the original function using the function pointer returned by dlsym. Both components restore the original functions when the patcher framework closes. Changes had to be made to support Power/PowerPC with the Linux dynamic loader patcher. Some of the changes: - Move code necessary for powerpc/power support to the patcher base. The code is needed by both the overwrite and linux components. - Move patch structure down to base and move the patch list to mca_patcher_base_module_t. The structure has been modified to include a function pointer to the function that will unapply the patch. This allows the mixing of multiple different types of patches in the patch_list. - Update linux patching code to keep track of the matching between got entry and original (unpatched) address. This allows us to completely clean up the patch on finalize. All patchers keep track of the changes they made so that they can be reversed when the patcher framework is closed. At this time there are bugs in the Linux dynamic loader patcher so its priority is lower than the overwrite patcher. Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov> |
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| .. | ||
| configure.m4 | ||
| Makefile.am | ||
| patcher_linux_component.c | ||
| patcher_linux_module.c | ||
| patcher_linux.h | ||