From 21c4ff80cba5e24932f3ef79c8482c0491630b2b Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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 <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
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 92f4e5f64f02c..e2c3c6a85f33b 100644
--- a/arch/powerpc/kernel/module_32.c
+++ b/arch/powerpc/kernel/module_32.c
@@ -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;
}
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index ba34001fca8e8..8dd1f0aae5d62 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -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;
}
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 41277963f47a8..2e11416231478 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 */
--
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