+++ Matthias Schiffer [06/06/19 10:14 +0200]:
On Mon, 2019-06-03 at 12:57 +0200, Matthias Schiffer wrote:For some time (050d18d1c651 "ARM: 8650/1: module: handle negative R_ARM_PREL31 addends correctly", v4.11+), building a kernel without CONFIG_MODULE_UNLOAD would lead to module loads failing on ARM systems with certain memory layouts, with messages like: imx_sdma: section 16 reloc 0 sym '': relocation 42 out of range (0x7f015260 -> 0xc0f5a5e8) (0x7f015260 is in the module load area, 0xc0f5a5e8 a regular vmalloc address; relocation 42 is R_ARM_PREL31) This is caused by relocatiosn in the .ARM.extab.exit.text and .ARM.exidx.exit.text sections referencing the .exit.text section. As the module loader will omit loading .exit.text without CONFIG_MODULE_UNLOAD, there will be relocations from loaded to unloaded sections; the resulting huge offsets trigger the sanity checks added in 050d18d1c651. IA64 might be affected by a similar issue - sections with names like .IA_64.unwind.exit.text and .IA_64.unwind_info.exit.text appear in the ld script - but I don't know much about that arch. Also, I'm not sure if this is stable-worthy - just enabling CONFIG_MODULE_UNLOAD should be a viable workaround on affected kernels. Kind regards, MatthiasHi, any comments on these patches? If not, who is going to take them in their tree?
I don't mind either way. I can take the patches through my tree if Russell ack's the second one (after comments have been addressed). Thanks! Jessica
|