Commit 21c4ff80 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Paul Mackerras

[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: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 0909c8c2
......@@ -24,6 +24,8 @@
#include <linux/kernel.h>
#include <linux/cache.h>
#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;
}
......
......@@ -22,6 +22,9 @@
#include <linux/vmalloc.h>
#include <asm/module.h>
#include <asm/uaccess.h>
#include <asm/firmware.h>
#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;
}
......
......@@ -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 */
......
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