The module load code has previously had entirely separate
implementations for rel & rela style relocs, which unnecessarily
duplicates a whole lot of code. Unify the implementations of both types
of reloc, sharing the bulk of the code.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
---
arch/mips/include/asm/module.h | 8 +-
arch/mips/kernel/Makefile | 1 -
arch/mips/kernel/module-rela.c | 202 -----------------------------------------
arch/mips/kernel/module.c | 195 ++++++++++++++++++++++++++++++---------
4 files changed, 154 insertions(+), 252 deletions(-)
delete mode 100644 arch/mips/kernel/module-rela.c
diff --git a/arch/mips/include/asm/module.h b/arch/mips/include/asm/module.h
index 702c273e67a9..e51add184717 100644
--- a/arch/mips/include/asm/module.h
+++ b/arch/mips/include/asm/module.h
@@ -47,8 +47,8 @@ typedef struct {
#define Elf_Mips_Rel Elf32_Rel
#define Elf_Mips_Rela Elf32_Rela
-#define ELF_MIPS_R_SYM(rel) ELF32_R_SYM(rel.r_info)
-#define ELF_MIPS_R_TYPE(rel) ELF32_R_TYPE(rel.r_info)
+#define ELF_MIPS_R_SYM(rel) ELF32_R_SYM((rel).r_info)
+#define ELF_MIPS_R_TYPE(rel) ELF32_R_TYPE((rel).r_info)
#endif
@@ -65,8 +65,8 @@ typedef struct {
#define Elf_Mips_Rel Elf64_Mips_Rel
#define Elf_Mips_Rela Elf64_Mips_Rela
-#define ELF_MIPS_R_SYM(rel) (rel.r_sym)
-#define ELF_MIPS_R_TYPE(rel) (rel.r_type)
+#define ELF_MIPS_R_SYM(rel) ((rel).r_sym)
+#define ELF_MIPS_R_TYPE(rel) ((rel).r_type)
#endif
diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index 9a0e37b92ce0..f0edd7e8a0b7 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -31,7 +31,6 @@ obj-$(CONFIG_SYNC_R4K) += sync-r4k.o
obj-$(CONFIG_DEBUG_FS) += segment.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-$(CONFIG_MODULES) += module.o
-obj-$(CONFIG_MODULES_USE_ELF_RELA) += module-rela.o
obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.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
deleted file mode 100644
index 781168834456..000000000000
--- a/arch/mips/kernel/module-rela.c
+++ /dev/null
@@ -1,202 +0,0 @@
-/*
- * 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
- * Copyright (C) 2015 Imagination Technologies Ltd.
- */
-
-#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 RELA relocation\n",
- me->name);
- return -ENOEXEC;
- }
-
- if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
- pr_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_pc_rela(struct module *me, u32 *location, Elf_Addr v,
- unsigned bits)
-{
- unsigned long mask = GENMASK(bits - 1, 0);
- unsigned long se_bits;
- long offset;
-
- if (v % 4) {
- pr_err("module %s: dangerous R_MIPS_PC%u RELA relocation\n",
- me->name, bits);
- return -ENOEXEC;
- }
-
- offset = ((long)v - (long)location) >> 2;
-
- /* check the sign bit onwards are identical - ie. we didn't overflow */
- se_bits = (offset & BIT(bits - 1)) ? ~0ul : 0;
- if ((offset & ~mask) != (se_bits & ~mask)) {
- pr_err("module %s: relocation overflow\n", me->name);
- return -ENOEXEC;
- }
-
- *location = (*location & ~mask) | (offset & mask);
-
- return 0;
-}
-
-static int apply_r_mips_pc16_rela(struct module *me, u32 *location, Elf_Addr v)
-{
- return apply_r_mips_pc_rela(me, location, v, 16);
-}
-
-static int apply_r_mips_pc21_rela(struct module *me, u32 *location, Elf_Addr v)
-{
- return apply_r_mips_pc_rela(me, location, v, 21);
-}
-
-static int apply_r_mips_pc26_rela(struct module *me, u32 *location, Elf_Addr v)
-{
- return apply_r_mips_pc_rela(me, location, v, 26);
-}
-
-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_PC16] = apply_r_mips_pc16_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,
- [R_MIPS_PC21_S2] = apply_r_mips_pc21_rela,
- [R_MIPS_PC26_S2] = apply_r_mips_pc26_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;
- int (*handler)(struct module *me, u32 *location, Elf_Addr v);
- Elf_Sym *sym;
- u32 *location;
- unsigned int i, type;
- 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 (sym->st_value >= -MAX_ERRNO) {
- /* Ignore unresolved weak symbol */
- if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
- continue;
- pr_warn("%s: Unknown symbol %s\n",
- me->name, strtab + sym->st_name);
- return -ENOENT;
- }
-
- type = ELF_MIPS_R_TYPE(rel[i]);
-
- if (type < ARRAY_SIZE(reloc_handlers_rela))
- handler = reloc_handlers_rela[type];
- else
- handler = NULL;
-
- if (!handler) {
- pr_err("%s: Unknown relocation type %u\n",
- me->name, type);
- return -EINVAL;
- }
-
- v = sym->st_value + rel[i].r_addend;
- res = handler(me, location, v);
- if (res)
- return res;
- }
-
- return 0;
-}
diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c
index ddcfb59593b6..b250eb0c4fc1 100644
--- a/arch/mips/kernel/module.c
+++ b/arch/mips/kernel/module.c
@@ -53,22 +53,25 @@ void *module_alloc(unsigned long size)
}
#endif
-int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_none(struct module *me, u32 *location,
+ u32 base, Elf_Addr v, bool rela)
{
return 0;
}
-static int apply_r_mips_32_rel(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_32(struct module *me, u32 *location,
+ u32 base, Elf_Addr v, bool rela)
{
- *location += v;
+ *location = base + v;
return 0;
}
-static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_26(struct module *me, u32 *location,
+ u32 base, Elf_Addr v, bool rela)
{
if (v % 4) {
- pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
+ pr_err("module %s: dangerous R_MIPS_26 relocation\n",
me->name);
return -ENOEXEC;
}
@@ -80,15 +83,22 @@ static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
}
*location = (*location & ~0x03ffffff) |
- ((*location + (v >> 2)) & 0x03ffffff);
+ ((base + (v >> 2)) & 0x03ffffff);
return 0;
}
-static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_hi16(struct module *me, u32 *location,
+ u32 base, Elf_Addr v, bool rela)
{
struct mips_hi16 *n;
+ if (rela) {
+ *location = (*location & 0xffff0000) |
+ ((((long long) v + 0x8000LL) >> 16) & 0xffff);
+ return 0;
+ }
+
/*
* We cannot relocate this one now because we don't know the value of
* the carry we need to add. Save the information, and let LO16 do the
@@ -117,12 +127,18 @@ static void free_relocation_chain(struct mips_hi16 *l)
}
}
-static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_lo16(struct module *me, u32 *location,
+ u32 base, Elf_Addr v, bool rela)
{
- unsigned long insnlo = *location;
+ unsigned long insnlo = base;
struct mips_hi16 *l;
Elf_Addr val, vallo;
+ if (rela) {
+ *location = (*location & 0xffff0000) | (v & 0xffff);
+ return 0;
+ }
+
/* Sign extend the addend we extract from the lo insn. */
vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
@@ -178,26 +194,26 @@ static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
free_relocation_chain(l);
me->arch.r_mips_hi16_list = NULL;
- pr_err("module %s: dangerous R_MIPS_LO16 REL relocation\n", me->name);
+ pr_err("module %s: dangerous R_MIPS_LO16 relocation\n", me->name);
return -ENOEXEC;
}
-static int apply_r_mips_pc_rel(struct module *me, u32 *location, Elf_Addr v,
- unsigned bits)
+static int apply_r_mips_pc(struct module *me, u32 *location, u32 base,
+ Elf_Addr v, unsigned int bits)
{
unsigned long mask = GENMASK(bits - 1, 0);
unsigned long se_bits;
long offset;
if (v % 4) {
- pr_err("module %s: dangerous R_MIPS_PC%u REL relocation\n",
+ pr_err("module %s: dangerous R_MIPS_PC%u relocation\n",
me->name, bits);
return -ENOEXEC;
}
- /* retrieve & sign extend implicit addend */
- offset = *location & mask;
+ /* retrieve & sign extend implicit addend if any */
+ offset = base & mask;
offset |= (offset & BIT(bits - 1)) ? ~mask : 0;
offset += ((long)v - (long)location) >> 2;
@@ -214,56 +230,121 @@ static int apply_r_mips_pc_rel(struct module *me, u32 *location, Elf_Addr v,
return 0;
}
-static int apply_r_mips_pc16_rel(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_pc16(struct module *me, u32 *location,
+ u32 base, Elf_Addr v, bool rela)
{
- return apply_r_mips_pc_rel(me, location, v, 16);
+ return apply_r_mips_pc(me, location, base, v, 16);
}
-static int apply_r_mips_pc21_rel(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_pc21(struct module *me, u32 *location,
+ u32 base, Elf_Addr v, bool rela)
{
- return apply_r_mips_pc_rel(me, location, v, 21);
+ return apply_r_mips_pc(me, location, base, v, 21);
}
-static int apply_r_mips_pc26_rel(struct module *me, u32 *location, Elf_Addr v)
+static int apply_r_mips_pc26(struct module *me, u32 *location,
+ u32 base, Elf_Addr v, bool rela)
{
- return apply_r_mips_pc_rel(me, location, v, 26);
+ return apply_r_mips_pc(me, location, base, v, 26);
}
-static int (*reloc_handlers_rel[]) (struct module *me, u32 *location,
- Elf_Addr v) = {
+static int apply_r_mips_64(struct module *me, u32 *location,
+ u32 base, Elf_Addr v, bool rela)
+{
+ if (WARN_ON(!rela))
+ return -EINVAL;
+
+ *(Elf_Addr *)location = v;
+
+ return 0;
+}
+
+static int apply_r_mips_higher(struct module *me, u32 *location,
+ u32 base, Elf_Addr v, bool rela)
+{
+ if (WARN_ON(!rela))
+ return -EINVAL;
+
+ *location = (*location & 0xffff0000) |
+ ((((long long)v + 0x80008000LL) >> 32) & 0xffff);
+
+ return 0;
+}
+
+static int apply_r_mips_highest(struct module *me, u32 *location,
+ u32 base, Elf_Addr v, bool rela)
+{
+ if (WARN_ON(!rela))
+ return -EINVAL;
+
+ *location = (*location & 0xffff0000) |
+ ((((long long)v + 0x800080008000LL) >> 48) & 0xffff);
+
+ return 0;
+}
+
+/**
+ * reloc_handler() - Apply a particular relocation to a module
+ * @me: the module to apply the reloc to
+ * @location: the address at which the reloc is to be applied
+ * @base: the existing value at location for REL-style; 0 for RELA-style
+ * @v: the value of the reloc, with addend for RELA-style
+ *
+ * Each implemented reloc_handler function applies a particular type of
+ * relocation to the module @me. Relocs that may be found in either REL or RELA
+ * variants can be handled by making use of the @base & @v parameters which are
+ * set to values which abstract the difference away from the particular reloc
+ * implementations.
+ *
+ * Return: 0 upon success, else -ERRNO
+ */
+typedef int (*reloc_handler)(struct module *me, u32 *location,
+ u32 base, Elf_Addr v, bool rela);
+
+/* The handlers for known reloc types */
+static reloc_handler reloc_handlers[] = {
[R_MIPS_NONE] = apply_r_mips_none,
- [R_MIPS_32] = apply_r_mips_32_rel,
- [R_MIPS_26] = apply_r_mips_26_rel,
- [R_MIPS_HI16] = apply_r_mips_hi16_rel,
- [R_MIPS_LO16] = apply_r_mips_lo16_rel,
- [R_MIPS_PC16] = apply_r_mips_pc16_rel,
- [R_MIPS_PC21_S2] = apply_r_mips_pc21_rel,
- [R_MIPS_PC26_S2] = apply_r_mips_pc26_rel,
+ [R_MIPS_32] = apply_r_mips_32,
+ [R_MIPS_26] = apply_r_mips_26,
+ [R_MIPS_HI16] = apply_r_mips_hi16,
+ [R_MIPS_LO16] = apply_r_mips_lo16,
+ [R_MIPS_PC16] = apply_r_mips_pc16,
+ [R_MIPS_64] = apply_r_mips_64,
+ [R_MIPS_HIGHER] = apply_r_mips_higher,
+ [R_MIPS_HIGHEST] = apply_r_mips_highest,
+ [R_MIPS_PC21_S2] = apply_r_mips_pc21,
+ [R_MIPS_PC26_S2] = apply_r_mips_pc26,
};
-int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
- unsigned int symindex, unsigned int relsec,
- struct module *me)
+static int __apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
+ unsigned int symindex, unsigned int relsec,
+ struct module *me, bool rela)
{
- Elf_Mips_Rel *rel = (void *) sechdrs[relsec].sh_addr;
- int (*handler)(struct module *me, u32 *location, Elf_Addr v);
+ union {
+ Elf_Mips_Rel *rel;
+ Elf_Mips_Rela *rela;
+ } r;
+ reloc_handler handler;
Elf_Sym *sym;
- u32 *location;
+ u32 *location, base;
unsigned int i, type;
Elf_Addr v;
int err = 0;
+ size_t reloc_sz;
pr_debug("Applying relocate section %u to %u\n", relsec,
sechdrs[relsec].sh_info);
+ r.rel = (void *)sechdrs[relsec].sh_addr;
+ reloc_sz = rela ? sizeof(*r.rela) : sizeof(*r.rel);
me->arch.r_mips_hi16_list = NULL;
- for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+ for (i = 0; i < sechdrs[relsec].sh_size / reloc_sz; i++) {
/* This is where to make the change */
location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
- + rel[i].r_offset;
+ + r.rel->r_offset;
/* This is the symbol it is referring to */
sym = (Elf_Sym *)sechdrs[symindex].sh_addr
- + ELF_MIPS_R_SYM(rel[i]);
+ + ELF_MIPS_R_SYM(*r.rel);
if (sym->st_value >= -MAX_ERRNO) {
/* Ignore unresolved weak symbol */
if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
@@ -274,10 +355,9 @@ int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
goto out;
}
- type = ELF_MIPS_R_TYPE(rel[i]);
-
- if (type < ARRAY_SIZE(reloc_handlers_rel))
- handler = reloc_handlers_rel[type];
+ type = ELF_MIPS_R_TYPE(*r.rel);
+ if (type < ARRAY_SIZE(reloc_handlers))
+ handler = reloc_handlers[type];
else
handler = NULL;
@@ -288,8 +368,17 @@ int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
goto out;
}
- v = sym->st_value;
- err = handler(me, location, v);
+ if (rela) {
+ v = sym->st_value + r.rela->r_addend;
+ base = 0;
+ r.rela = &r.rela[1];
+ } else {
+ v = sym->st_value;
+ base = *location;
+ r.rel = &r.rel[1];
+ }
+
+ err = handler(me, location, base, v, rela);
if (err)
goto out;
}
@@ -312,6 +401,22 @@ int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
return err;
}
+int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
+ unsigned int symindex, unsigned int relsec,
+ struct module *me)
+{
+ return __apply_relocate(sechdrs, strtab, symindex, relsec, me, false);
+}
+
+#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)
+{
+ return __apply_relocate(sechdrs, strtab, symindex, relsec, me, true);
+}
+#endif /* CONFIG_MODULES_USE_ELF_RELA */
+
/* Given an address, look for it in the module exception tables. */
const struct exception_table_entry *search_module_dbetables(unsigned long addr)
{
--
2.12.1
