From 21c4ff80cba5e24932f3ef79c8482c0491630b2b Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Fri, 20 Oct 2006 11:47:19 +1000 Subject: [PATCH] [POWERPC] Support feature fixups in modules This patch adds support for feature fixups in modules. This involves adding support for R_PPC64_REL64 relocs to the 64 bits module loader. It also modifies modpost.c to ignore the powerpc fixup sections (or it would warn when used in .init.text). Signed-off-by: Benjamin Herrenschmidt Acked-by: Olof Johansson Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/module_32.c | 39 +++++++++++++++++++++++--------- arch/powerpc/kernel/module_64.c | 49 +++++++++++++++++++++++++++++++++-------- scripts/mod/modpost.c | 2 ++ 3 files changed, 71 insertions(+), 19 deletions(-) diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c index 92f4e5f..e2c3c6a 100644 --- a/arch/powerpc/kernel/module_32.c +++ b/arch/powerpc/kernel/module_32.c @@ -24,6 +24,8 @@ #include #include +#include "setup.h" + #if 0 #define DEBUGP printk #else @@ -269,33 +271,50 @@ int apply_relocate_add(Elf32_Shdr *sechdrs, return 0; } +static const Elf_Shdr *find_section(const Elf_Ehdr *hdr, + const Elf_Shdr *sechdrs, + const char *name) +{ + char *secstrings; + unsigned int i; + + secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; + for (i = 1; i < hdr->e_shnum; i++) + if (strcmp(secstrings+sechdrs[i].sh_name, name) == 0) + return &sechdrs[i]; + return NULL; +} + int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me) { - char *secstrings; - unsigned int i; + const Elf_Shdr *sect; me->arch.bug_table = NULL; me->arch.num_bugs = 0; /* Find the __bug_table section, if present */ - secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; - for (i = 1; i < hdr->e_shnum; i++) { - if (strcmp(secstrings+sechdrs[i].sh_name, "__bug_table")) - continue; - me->arch.bug_table = (void *) sechdrs[i].sh_addr; - me->arch.num_bugs = sechdrs[i].sh_size / sizeof(struct bug_entry); - break; + sect = find_section(hdr, sechdrs, "__bug_table"); + if (sect != NULL) { + me->arch.bug_table = (void *) sect->sh_addr; + me->arch.num_bugs = sect->sh_size / sizeof(struct bug_entry); } - /* + /* * Strictly speaking this should have a spinlock to protect against * traversals, but since we only traverse on BUG()s, a spinlock * could potentially lead to deadlock and thus be counter-productive. */ list_add(&me->arch.bug_list, &module_bug_list); + /* Apply feature fixups */ + sect = find_section(hdr, sechdrs, "__ftr_fixup"); + if (sect != NULL) + do_feature_fixups(cur_cpu_spec->cpu_features, + (void *)sect->sh_addr, + (void *)sect->sh_addr + sect->sh_size); + return 0; } diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index ba34001..8dd1f0a 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -22,6 +22,9 @@ #include #include #include +#include + +#include "setup.h" /* FIXME: We don't do .init separately. To do this, we'd need to have a separate r2 value in the init and core section, and stub between @@ -400,6 +403,11 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, | (value & 0x03fffffc); break; + case R_PPC64_REL64: + /* 64 bits relative (used by features fixups) */ + *location = value - (unsigned long)location; + break; + default: printk("%s: Unknown ADD relocation: %lu\n", me->name, @@ -413,23 +421,33 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, LIST_HEAD(module_bug_list); -int module_finalize(const Elf_Ehdr *hdr, - const Elf_Shdr *sechdrs, struct module *me) +static const Elf_Shdr *find_section(const Elf_Ehdr *hdr, + const Elf_Shdr *sechdrs, + const char *name) { char *secstrings; unsigned int i; + secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; + for (i = 1; i < hdr->e_shnum; i++) + if (strcmp(secstrings+sechdrs[i].sh_name, name) == 0) + return &sechdrs[i]; + return NULL; +} + +int module_finalize(const Elf_Ehdr *hdr, + const Elf_Shdr *sechdrs, struct module *me) +{ + const Elf_Shdr *sect; + me->arch.bug_table = NULL; me->arch.num_bugs = 0; /* Find the __bug_table section, if present */ - secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; - for (i = 1; i < hdr->e_shnum; i++) { - if (strcmp(secstrings+sechdrs[i].sh_name, "__bug_table")) - continue; - me->arch.bug_table = (void *) sechdrs[i].sh_addr; - me->arch.num_bugs = sechdrs[i].sh_size / sizeof(struct bug_entry); - break; + sect = find_section(hdr, sechdrs, "__bug_table"); + if (sect != NULL) { + me->arch.bug_table = (void *) sect->sh_addr; + me->arch.num_bugs = sect->sh_size / sizeof(struct bug_entry); } /* @@ -439,6 +457,19 @@ int module_finalize(const Elf_Ehdr *hdr, */ list_add(&me->arch.bug_list, &module_bug_list); + /* Apply feature fixups */ + sect = find_section(hdr, sechdrs, "__ftr_fixup"); + if (sect != NULL) + do_feature_fixups(cur_cpu_spec->cpu_features, + (void *)sect->sh_addr, + (void *)sect->sh_addr + sect->sh_size); + + sect = find_section(hdr, sechdrs, "__fw_ftr_fixup"); + if (sect != NULL) + do_feature_fixups(powerpc_firmware_features, + (void *)sect->sh_addr, + (void *)sect->sh_addr + sect->sh_size); + return 0; } diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 4127796..2e11416 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -921,6 +921,8 @@ static int init_section_ref_ok(const char *name) ".fixup", ".smp_locks", ".plt", /* seen on ARCH=um build on x86_64. Harmless */ + "__ftr_fixup", /* powerpc cpu feature fixup */ + "__fw_ftr_fixup", /* powerpc firmware feature fixup */ NULL }; /* Start of section names */ -- 2.7.4