On Tue, 1 Dec 2009 04:46:00 am Neil Horman wrote: > Paul, Ben, given that Rusty hasn't come back with any opinion on this patch, > do you > feel comfortable merging it via the ppc tree? Currently the earlyinit routine > is only compiled in and used for your arch, so I think its fairly benign.
Sorry, I *did* track down the archives for linuxppc-dev, then find your post, then read your patch. But I didn't actually reply. Other than minor issues, there's one significant one: you shouldn't be trying to change rodata. It might work on PPC today, but it's poor form at least. How's this? Untested on ppc. Other changes: 1) I also changed reloc_start to an array; this is a good idea for any linker-defined symbols so the compiler can't make assumptions about size. 2) local.h? How about module.h? 3) I don't think the extra ". = 0" is necessary. 4) ARCH_USES_RELOC_ENTRIES isn't clear enough for me; I prefer ARCH_RELOCATE_KCRCTAB. module: handle ppc64 relocating kcrctabs when CONFIG_RELOCATABLE=y http://lists.ozlabs.org/pipermail/linuxppc-dev/2009-November/077972.html Inspired-by: Neil Horman <nhor...@tuxdriver.com> Signed-off-by: Rusty Russell <ru...@rustcorp.com.au> diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h --- a/arch/powerpc/include/asm/module.h +++ b/arch/powerpc/include/asm/module.h @@ -87,5 +87,10 @@ struct exception_table_entry; void sort_ex_table(struct exception_table_entry *start, struct exception_table_entry *finish); +#ifdef CONFIG_MODVERSIONS +#define ARCH_RELOCATES_KCRCTAB + +extern const unsigned long reloc_start[]; +#endif #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_MODULE_H */ diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -38,6 +38,9 @@ jiffies = jiffies_64 + 4; #endif SECTIONS { + . = 0; + reloc_start = .; + . = KERNELBASE; /* diff --git a/kernel/module.c b/kernel/module.c --- a/kernel/module.c +++ b/kernel/module.c @@ -1030,11 +1030,23 @@ static int try_to_force_load(struct modu } #ifdef CONFIG_MODVERSIONS +/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */ +static unsigned long maybe_relocated(unsigned long crc, + const struct module *crc_owner) +{ +#ifdef ARCH_RELOCATES_KCRCTAB + if (crc_owner == NULL) + return crc - (unsigned long)reloc_start; +#endif + return crc; +} + static int check_version(Elf_Shdr *sechdrs, unsigned int versindex, const char *symname, struct module *mod, - const unsigned long *crc) + const unsigned long *crc, + const struct module *crc_owner) { unsigned int i, num_versions; struct modversion_info *versions; @@ -1055,10 +1067,10 @@ static int check_version(Elf_Shdr *sechd if (strcmp(versions[i].name, symname) != 0) continue; - if (versions[i].crc == *crc) + if (versions[i].crc == maybe_relocated(*crc, crc_owner)) return 1; DEBUGP("Found checksum %lX vs module %lX\n", - *crc, versions[i].crc); + maybe_relocated(*crc, crc_owner), versions[i].crc); goto bad_version; } @@ -1081,7 +1093,8 @@ static inline int check_modstruct_versio if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL, &crc, true, false)) BUG(); - return check_version(sechdrs, versindex, "module_layout", mod, crc); + return check_version(sechdrs, versindex, "module_layout", mod, crc, + NULL); } /* First part is kernel version, which we ignore if module has crcs. */ @@ -1099,7 +1112,8 @@ static inline int check_version(Elf_Shdr unsigned int versindex, const char *symname, struct module *mod, - const unsigned long *crc) + const unsigned long *crc, + const struct module *crc_owner) { return 1; } @@ -1134,8 +1148,8 @@ static const struct kernel_symbol *resol /* use_module can fail due to OOM, or module initialization or unloading */ if (sym) { - if (!check_version(sechdrs, versindex, name, mod, crc) || - !use_module(mod, owner)) + if (!check_version(sechdrs, versindex, name, mod, crc, owner) + || !use_module(mod, owner)) sym = NULL; } return sym; _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
