Messages in this thread | | | Date | Mon, 21 Mar 2016 14:48:56 +0100 (CET) | From | Miroslav Benes <> | Subject | Re: [PATCH v5 2/6] module: preserve Elf information for livepatch modules |
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On Wed, 16 Mar 2016, Jessica Yu wrote:
> For livepatch modules, copy Elf section, symbol, and string information > from the load_info struct in the module loader. Persist copies of the > original symbol table and string table. > > Livepatch manages its own relocation sections in order to reuse module > loader code to write relocations. Livepatch modules must preserve Elf > information such as section indices in order to apply livepatch relocation > sections using the module loader's apply_relocate_add() function. > > In order to apply livepatch relocation sections, livepatch modules must > keep a complete copy of their original symbol table in memory. Normally, a > stripped down copy of a module's symbol table (containing only "core" > symbols) is made available through module->core_symtab. But for livepatch > modules, the symbol table copied into memory on module load must be exactly > the same as the symbol table produced when the patch module was compiled. > This is because the relocations in each livepatch relocation section refer > to their respective symbols with their symbol indices, and the original > symbol indices (and thus the symtab ordering) must be preserved in order > for apply_relocate_add() to find the right symbol. > > Signed-off-by: Jessica Yu <jeyu@redhat.com>
With a fix for a bug reported by kbuild test robot
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
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