4.4-stable review patch. If anyone has any objections, please let me know.
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Signed-off-by: chenzefeng chenzefeng2@huawei.com
On x86-64, for 32-bit PC-relacive branches, we can generate PLT32 relocation, instead of PC32 relocation. and R_X86_64_PLT32 can be treated the same as R_X86_64_PC32 since linux kernel doesn't use PLT.
commit b21ebf2fb4cd ("x86: Treat R_X86_64_PLT32 as R_X86_64_PC32") been fixed for the module loading, but not fixed for livepatch relocation, which will fail to load livepatch with the error message as follow: relocation failed for symbol <symbol name> at <symbol address>
This issue only effacted the kernel version from 4.0 to 4.6, becauce the function klp_write_module_reloc is introduced by: commit b700e7f03df5 ("livepatch: kernel: add support for live patching") and deleted by: commit 425595a7fc20 ("livepatch: reuse module loader code to write relocations")
Signed-off-by: chenzefeng chenzefeng2@huawei.com Reviewed-by: Petr Mladek pmladek@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kernel/livepatch.c | 1 + 1 file changed, 1 insertion(+)
--- a/arch/x86/kernel/livepatch.c +++ b/arch/x86/kernel/livepatch.c @@ -58,6 +58,7 @@ int klp_write_module_reloc(struct module val = (s32)value; break; case R_X86_64_PC32: + case R_X86_64_PLT32: val = (u32)(value - loc); break; default: