[PATCH] MIPS: Fix module.c build for 32 bit

From: Ralf Baechle
Date: Tue Aug 14 2012 - 11:13:59 EST


Fixes build failure introduced by "Make most arch asm/module.h files use
asm-generic/module.h" by moving all the RELA processing code to a
separate file to be used only for RELA processing on 64-bit kernels.

CC arch/mips/kernel/module.o
arch/mips/kernel/module.c:250:14: error: 'reloc_handlers_rela' defined but not
used [-Werror=unused-variable]
cc1: all warnings being treated as errors

make[6]: *** [arch/mips/kernel/module.o] Error 1

Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>

---
This is bigger than Jonas' suggested patch but far less #ifdefy.
A minimal fix would be to add __maybe_unused to the definition of
reloc_handlers_rela but imho __maybe_unused should be avoided where
possible.

I tested this on top of today's -next but ideally to keep bisectability
it should be applied early in the series before CONFIG_MODULES_USE_ELF_RELA
is introduced which would require trivial tweaking arch/mips/kernel/Makefile
tweaking.

arch/mips/kernel/Makefile | 1 +
arch/mips/kernel/module-rela.c | 145 +++++++++++++++++++++++++++++++++++++++++
arch/mips/kernel/module.c | 123 +---------------------------------
3 files changed, 147 insertions(+), 122 deletions(-)

diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index fdaf65e..cd1e6c2 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_SYNC_R4K) += sync-r4k.o

obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-$(CONFIG_MODULES) += mips_ksyms.o module.o
+obj-$(CONFIG_MODULES_USE_ELF_RELA) += module-rela.o

obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o

diff --git a/arch/mips/kernel/module-rela.c b/arch/mips/kernel/module-rela.c
new file mode 100644
index 0000000..61d6002
--- /dev/null
+++ b/arch/mips/kernel/module-rela.c
@@ -0,0 +1,145 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Copyright (C) 2001 Rusty Russell.
+ * Copyright (C) 2003, 2004 Ralf Baechle (ralf@xxxxxxxxxxxxxx)
+ * Copyright (C) 2005 Thiemo Seufer
+ */
+
+#include <linux/elf.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/moduleloader.h>
+
+extern int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v);
+
+static int apply_r_mips_32_rela(struct module *me, u32 *location, Elf_Addr v)
+{
+ *location = v;
+
+ return 0;
+}
+
+static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
+{
+ if (v % 4) {
+ pr_err("module %s: dangerous R_MIPS_26 RELArelocation\n",
+ me->name);
+ return -ENOEXEC;
+ }
+
+ if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
+ printk(KERN_ERR
+ "module %s: relocation overflow\n",
+ me->name);
+ return -ENOEXEC;
+ }
+
+ *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
+
+ return 0;
+}
+
+static int apply_r_mips_hi16_rela(struct module *me, u32 *location, Elf_Addr v)
+{
+ *location = (*location & 0xffff0000) |
+ ((((long long) v + 0x8000LL) >> 16) & 0xffff);
+
+ return 0;
+}
+
+static int apply_r_mips_lo16_rela(struct module *me, u32 *location, Elf_Addr v)
+{
+ *location = (*location & 0xffff0000) | (v & 0xffff);
+
+ return 0;
+}
+
+static int apply_r_mips_64_rela(struct module *me, u32 *location, Elf_Addr v)
+{
+ *(Elf_Addr *)location = v;
+
+ return 0;
+}
+
+static int apply_r_mips_higher_rela(struct module *me, u32 *location,
+ Elf_Addr v)
+{
+ *location = (*location & 0xffff0000) |
+ ((((long long) v + 0x80008000LL) >> 32) & 0xffff);
+
+ return 0;
+}
+
+static int apply_r_mips_highest_rela(struct module *me, u32 *location,
+ Elf_Addr v)
+{
+ *location = (*location & 0xffff0000) |
+ ((((long long) v + 0x800080008000LL) >> 48) & 0xffff);
+
+ return 0;
+}
+
+static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
+ Elf_Addr v) = {
+ [R_MIPS_NONE] = apply_r_mips_none,
+ [R_MIPS_32] = apply_r_mips_32_rela,
+ [R_MIPS_26] = apply_r_mips_26_rela,
+ [R_MIPS_HI16] = apply_r_mips_hi16_rela,
+ [R_MIPS_LO16] = apply_r_mips_lo16_rela,
+ [R_MIPS_64] = apply_r_mips_64_rela,
+ [R_MIPS_HIGHER] = apply_r_mips_higher_rela,
+ [R_MIPS_HIGHEST] = apply_r_mips_highest_rela
+};
+
+int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
+ unsigned int symindex, unsigned int relsec,
+ struct module *me)
+{
+ Elf_Mips_Rela *rel = (void *) sechdrs[relsec].sh_addr;
+ Elf_Sym *sym;
+ u32 *location;
+ unsigned int i;
+ Elf_Addr v;
+ int res;
+
+ pr_debug("Applying relocate section %u to %u\n", relsec,
+ sechdrs[relsec].sh_info);
+
+ for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+ /* This is where to make the change */
+ location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+ + rel[i].r_offset;
+ /* This is the symbol it is referring to */
+ sym = (Elf_Sym *)sechdrs[symindex].sh_addr
+ + ELF_MIPS_R_SYM(rel[i]);
+ if (IS_ERR_VALUE(sym->st_value)) {
+ /* Ignore unresolved weak symbol */
+ if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
+ continue;
+ printk(KERN_WARNING "%s: Unknown symbol %s\n",
+ me->name, strtab + sym->st_name);
+ return -ENOENT;
+ }
+
+ v = sym->st_value + rel[i].r_addend;
+
+ res = reloc_handlers_rela[ELF_MIPS_R_TYPE(rel[i])](me, location, v);
+ if (res)
+ return res;
+ }
+
+ return 0;
+}
diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c
index 1500c80..da6dcd9 100644
--- a/arch/mips/kernel/module.c
+++ b/arch/mips/kernel/module.c
@@ -53,7 +53,7 @@ void *module_alloc(unsigned long size)
}
#endif

-static int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v)
+int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v)
{
return 0;
}
@@ -65,13 +65,6 @@ static int apply_r_mips_32_rel(struct module *me, u32 *location, Elf_Addr v)
return 0;
}

-static int apply_r_mips_32_rela(struct module *me, u32 *location, Elf_Addr v)
-{
- *location = v;
-
- return 0;
-}
-
static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
{
if (v % 4) {
@@ -93,26 +86,6 @@ static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
return 0;
}

-static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
-{
- if (v % 4) {
- pr_err("module %s: dangerous R_MIPS_26 RELArelocation\n",
- me->name);
- return -ENOEXEC;
- }
-
- if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
- printk(KERN_ERR
- "module %s: relocation overflow\n",
- me->name);
- return -ENOEXEC;
- }
-
- *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
-
- return 0;
-}
-
static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
{
struct mips_hi16 *n;
@@ -134,14 +107,6 @@ static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
return 0;
}

-static int apply_r_mips_hi16_rela(struct module *me, u32 *location, Elf_Addr v)
-{
- *location = (*location & 0xffff0000) |
- ((((long long) v + 0x8000LL) >> 16) & 0xffff);
-
- return 0;
-}
-
static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
{
unsigned long insnlo = *location;
@@ -206,38 +171,6 @@ out_danger:
return -ENOEXEC;
}

-static int apply_r_mips_lo16_rela(struct module *me, u32 *location, Elf_Addr v)
-{
- *location = (*location & 0xffff0000) | (v & 0xffff);
-
- return 0;
-}
-
-static int apply_r_mips_64_rela(struct module *me, u32 *location, Elf_Addr v)
-{
- *(Elf_Addr *)location = v;
-
- return 0;
-}
-
-static int apply_r_mips_higher_rela(struct module *me, u32 *location,
- Elf_Addr v)
-{
- *location = (*location & 0xffff0000) |
- ((((long long) v + 0x80008000LL) >> 32) & 0xffff);
-
- return 0;
-}
-
-static int apply_r_mips_highest_rela(struct module *me, u32 *location,
- Elf_Addr v)
-{
- *location = (*location & 0xffff0000) |
- ((((long long) v + 0x800080008000LL) >> 48) & 0xffff);
-
- return 0;
-}
-
static int (*reloc_handlers_rel[]) (struct module *me, u32 *location,
Elf_Addr v) = {
[R_MIPS_NONE] = apply_r_mips_none,
@@ -247,18 +180,6 @@ static int (*reloc_handlers_rel[]) (struct module *me, u32 *location,
[R_MIPS_LO16] = apply_r_mips_lo16_rel
};

-static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
- Elf_Addr v) = {
- [R_MIPS_NONE] = apply_r_mips_none,
- [R_MIPS_32] = apply_r_mips_32_rela,
- [R_MIPS_26] = apply_r_mips_26_rela,
- [R_MIPS_HI16] = apply_r_mips_hi16_rela,
- [R_MIPS_LO16] = apply_r_mips_lo16_rela,
- [R_MIPS_64] = apply_r_mips_64_rela,
- [R_MIPS_HIGHER] = apply_r_mips_higher_rela,
- [R_MIPS_HIGHEST] = apply_r_mips_highest_rela
-};
-
int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
unsigned int symindex, unsigned int relsec,
struct module *me)
@@ -299,48 +220,6 @@ int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
return 0;
}

-#ifdef CONFIG_MODULES_USE_ELF_RELA
-int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
- unsigned int symindex, unsigned int relsec,
- struct module *me)
-{
- Elf_Mips_Rela *rel = (void *) sechdrs[relsec].sh_addr;
- Elf_Sym *sym;
- u32 *location;
- unsigned int i;
- Elf_Addr v;
- int res;
-
- pr_debug("Applying relocate section %u to %u\n", relsec,
- sechdrs[relsec].sh_info);
-
- for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
- /* This is where to make the change */
- location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
- + rel[i].r_offset;
- /* This is the symbol it is referring to */
- sym = (Elf_Sym *)sechdrs[symindex].sh_addr
- + ELF_MIPS_R_SYM(rel[i]);
- if (IS_ERR_VALUE(sym->st_value)) {
- /* Ignore unresolved weak symbol */
- if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
- continue;
- printk(KERN_WARNING "%s: Unknown symbol %s\n",
- me->name, strtab + sym->st_name);
- return -ENOENT;
- }
-
- v = sym->st_value + rel[i].r_addend;
-
- res = reloc_handlers_rela[ELF_MIPS_R_TYPE(rel[i])](me, location, v);
- if (res)
- return res;
- }
-
- return 0;
-}
-#endif
-
/* Given an address, look for it in the module exception tables. */
const struct exception_table_entry *search_module_dbetables(unsigned long addr)
{
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/