Re: [Crash-utility] [PATCH] [PPC32] Fix vmalloc address translation for BookE

----- Original Message ----- > (2012/01/16 14:15), Suzuki K. Poulose wrote: >> This patch fixes the vmalloc address translation for BookE.This >> patch is based on the PPC44x definitions and may not work fine for >> other systems. >> >> crash> mod >> mod: cannot access vmalloc'd module memory >> crash> >> >> >> After the patch : >> >> crash> mod >> MODULE NAME SIZE OBJECT FILE >> d1018fd8 mbcache 6023 (not loaded) [CONFIG_KALLSYMS] >> d1077190 jbd 58360 (not loaded) [CONFIG_KALLSYMS] >> d107ca98 llc 4525 (not loaded) [CONFIG_KALLSYMS] >> d1130de4 ext3 203186 (not loaded) [CONFIG_KALLSYMS] >> d114bbac squashfs 26129 (not loaded) [CONFIG_KALLSYMS] >> >> >> On ppc44x, the virtual-address is split as below : >> >> Bits |0 10|11 19|20 31| >> ----------------------------------- >> | PGD | PMD | PAGE_OFFSET | >> ----------------------------------- >> >> The PAGE_BASE_ADDR is a 64bit value(of type phys_addr_t). >> >> Note : I am not sure how do we distinguish the different values (PGDIR_SHIFT etc) >> for different PPC32 systems. Since there are a lot of different platforms >> under PPC32, we need some mechanism to dynamically determine the PGDIR, PTE >> shift values. One option is to put the information in the VMCOREINFO. > > Hi Suzuki, > > How about using powerpc_base_platform symbol? > > *PTRRELOC(&powerpc_base_platform) = t->platform; > > $ grep -rIw platform arch/powerpc/kernel/cputable.c > /* The platform string corresponding to the real PVR */ > .platform = "power3", > .platform = "power3", > .platform = "rs64", > .platform = "rs64", > .platform = "rs64", > .platform = "rs64", > .platform = "power4", > .platform = "power4", > : > : > > This kconfig based platform string data can be read > base_platform = symbol_value("powerpc_base_platform symbols"); > read_string(base_platform, buf, buffer-size); > at ppc_init(POST_GDB). > > I think platform can be distinguished with following naming rules. > - CONFIG_40x=y: platform is "ppc403" > - CONFIG_44x=y: platform is "ppc440" > > Thanks, > Toshi That makes good sense. Suzuki, are you re-working the patch with Toshi's suggestion?