mirror of https://gitee.com/openkylin/linux.git
MIPS: module: optimize module relocations processing
For now, module relocation functions are implemented as an array of handlers of type reloc_handler_t. Convert that array into a single switch-case function to: - remove unused arguments; - change the return type of simple handlers to void; - remove the array and don't use any data at all; - avoid using indirect calls; - allow the compiler to inline and greatly optimize the relocation function[s]. The result on MIPS32 R2 with GCC 10.2 -O2 is: scripts/bloat-o-meter -c arch/mips/kernel/__module.o arch/mips/kernel/module.o add/remove: 1/11 grow/shrink: 1/0 up/down: 876/-1436 (-560) Function old new delta apply_relocate 456 1148 +692 apply_r_mips_pc - 184 +184 apply_r_mips_none 8 - -8 apply_r_mips_32 16 - -16 apply_r_mips_64 76 - -76 apply_r_mips_highest 88 - -88 apply_r_mips_higher 108 - -108 apply_r_mips_26 132 - -132 apply_r_mips_pc26 160 - -160 apply_r_mips_pc21 160 - -160 apply_r_mips_pc16 160 - -160 apply_r_mips_hi16 172 - -172 apply_r_mips_lo16 356 - -356 Total: Before=2608, After=2048, chg -21.47% add/remove: 0/0 grow/shrink: 0/0 up/down: 0/0 (0) Data old new delta Total: Before=12, After=12, chg +0.00% add/remove: 0/1 grow/shrink: 0/0 up/down: 0/-248 (-248) RO Data old new delta reloc_handlers 248 - -248 Total: Before=248, After=0, chg -100.00% All functions were collapsed into a single one that is called directly by $(srctree)/kernel/module.c. Signed-off-by: Alexander Lobakin <alobakin@pm.me> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
This commit is contained in:
Alexander Lobakin
Thomas Bogendoerfer
parent
76d7fff22b
commit
049a68efbf
|
|
@ -40,22 +40,13 @@ void *module_alloc(unsigned long size)
|
|||
}
|
||||
#endif
|
||||
|
||||
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(struct module *me, u32 *location,
|
||||
u32 base, Elf_Addr v, bool rela)
|
||||
static void apply_r_mips_32(u32 *location, u32 base, Elf_Addr v)
|
||||
{
|
||||
*location = base + v;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int apply_r_mips_26(struct module *me, u32 *location,
|
||||
u32 base, Elf_Addr v, bool rela)
|
||||
static int apply_r_mips_26(struct module *me, u32 *location, u32 base,
|
||||
Elf_Addr v)
|
||||
{
|
||||
if (v % 4) {
|
||||
pr_err("module %s: dangerous R_MIPS_26 relocation\n",
|
||||
|
|
@ -75,8 +66,8 @@ static int apply_r_mips_26(struct module *me, u32 *location,
|
|||
return 0;
|
||||
}
|
||||
|
||||
static int apply_r_mips_hi16(struct module *me, u32 *location,
|
||||
u32 base, Elf_Addr v, bool rela)
|
||||
static int apply_r_mips_hi16(struct module *me, u32 *location, Elf_Addr v,
|
||||
bool rela)
|
||||
{
|
||||
struct mips_hi16 *n;
|
||||
|
||||
|
|
@ -217,26 +208,25 @@ static int apply_r_mips_pc(struct module *me, u32 *location, u32 base,
|
|||
return 0;
|
||||
}
|
||||
|
||||
static int apply_r_mips_pc16(struct module *me, u32 *location,
|
||||
u32 base, Elf_Addr v, bool rela)
|
||||
static int apply_r_mips_pc16(struct module *me, u32 *location, u32 base,
|
||||
Elf_Addr v)
|
||||
{
|
||||
return apply_r_mips_pc(me, location, base, v, 16);
|
||||
}
|
||||
|
||||
static int apply_r_mips_pc21(struct module *me, u32 *location,
|
||||
u32 base, Elf_Addr v, bool rela)
|
||||
static int apply_r_mips_pc21(struct module *me, u32 *location, u32 base,
|
||||
Elf_Addr v)
|
||||
{
|
||||
return apply_r_mips_pc(me, location, base, v, 21);
|
||||
}
|
||||
|
||||
static int apply_r_mips_pc26(struct module *me, u32 *location,
|
||||
u32 base, Elf_Addr v, bool rela)
|
||||
static int apply_r_mips_pc26(struct module *me, u32 *location, u32 base,
|
||||
Elf_Addr v)
|
||||
{
|
||||
return apply_r_mips_pc(me, location, base, v, 26);
|
||||
}
|
||||
|
||||
static int apply_r_mips_64(struct module *me, u32 *location,
|
||||
u32 base, Elf_Addr v, bool rela)
|
||||
static int apply_r_mips_64(u32 *location, Elf_Addr v, bool rela)
|
||||
{
|
||||
if (WARN_ON(!rela))
|
||||
return -EINVAL;
|
||||
|
|
@ -246,8 +236,7 @@ static int apply_r_mips_64(struct module *me, u32 *location,
|
|||
return 0;
|
||||
}
|
||||
|
||||
static int apply_r_mips_higher(struct module *me, u32 *location,
|
||||
u32 base, Elf_Addr v, bool rela)
|
||||
static int apply_r_mips_higher(u32 *location, Elf_Addr v, bool rela)
|
||||
{
|
||||
if (WARN_ON(!rela))
|
||||
return -EINVAL;
|
||||
|
|
@ -258,8 +247,7 @@ static int apply_r_mips_higher(struct module *me, u32 *location,
|
|||
return 0;
|
||||
}
|
||||
|
||||
static int apply_r_mips_highest(struct module *me, u32 *location,
|
||||
u32 base, Elf_Addr v, bool rela)
|
||||
static int apply_r_mips_highest(u32 *location, Elf_Addr v, bool rela)
|
||||
{
|
||||
if (WARN_ON(!rela))
|
||||
return -EINVAL;
|
||||
|
|
@ -272,12 +260,14 @@ static int apply_r_mips_highest(struct module *me, u32 *location,
|
|||
|
||||
/**
|
||||
* reloc_handler() - Apply a particular relocation to a module
|
||||
* @type: type of the relocation to apply
|
||||
* @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
|
||||
* @rela: indication of is this a RELA (true) or REL (false) relocation
|
||||
*
|
||||
* Each implemented reloc_handler function applies a particular type of
|
||||
* Each implemented relocation 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
|
||||
|
|
@ -285,23 +275,40 @@ static int apply_r_mips_highest(struct module *me, u32 *location,
|
|||
*
|
||||
* Return: 0 upon success, else -ERRNO
|
||||
*/
|
||||
typedef int (*reloc_handler)(struct module *me, u32 *location,
|
||||
u32 base, Elf_Addr v, bool rela);
|
||||
static int reloc_handler(u32 type, struct module *me, u32 *location, u32 base,
|
||||
Elf_Addr v, bool rela)
|
||||
{
|
||||
switch (type) {
|
||||
case R_MIPS_NONE:
|
||||
break;
|
||||
case R_MIPS_32:
|
||||
apply_r_mips_32(location, base, v);
|
||||
break;
|
||||
case R_MIPS_26:
|
||||
return apply_r_mips_26(me, location, base, v);
|
||||
case R_MIPS_HI16:
|
||||
return apply_r_mips_hi16(me, location, v, rela);
|
||||
case R_MIPS_LO16:
|
||||
return apply_r_mips_lo16(me, location, base, v, rela);
|
||||
case R_MIPS_PC16:
|
||||
return apply_r_mips_pc16(me, location, base, v);
|
||||
case R_MIPS_PC21_S2:
|
||||
return apply_r_mips_pc21(me, location, base, v);
|
||||
case R_MIPS_PC26_S2:
|
||||
return apply_r_mips_pc26(me, location, base, v);
|
||||
case R_MIPS_64:
|
||||
return apply_r_mips_64(location, v, rela);
|
||||
case R_MIPS_HIGHER:
|
||||
return apply_r_mips_higher(location, v, rela);
|
||||
case R_MIPS_HIGHEST:
|
||||
return apply_r_mips_highest(location, v, rela);
|
||||
default:
|
||||
pr_err("%s: Unknown relocation type %u\n", me->name, type);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
/* 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,
|
||||
[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,
|
||||
};
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int __apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
|
||||
unsigned int symindex, unsigned int relsec,
|
||||
|
|
@ -311,7 +318,6 @@ static int __apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
|
|||
Elf_Mips_Rel *rel;
|
||||
Elf_Mips_Rela *rela;
|
||||
} r;
|
||||
reloc_handler handler;
|
||||
Elf_Sym *sym;
|
||||
u32 *location, base;
|
||||
unsigned int i, type;
|
||||
|
|
@ -343,17 +349,6 @@ static int __apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
|
|||
}
|
||||
|
||||
type = ELF_MIPS_R_TYPE(*r.rel);
|
||||
if (type < ARRAY_SIZE(reloc_handlers))
|
||||
handler = reloc_handlers[type];
|
||||
else
|
||||
handler = NULL;
|
||||
|
||||
if (!handler) {
|
||||
pr_err("%s: Unknown relocation type %u\n",
|
||||
me->name, type);
|
||||
err = -EINVAL;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if (rela) {
|
||||
v = sym->st_value + r.rela->r_addend;
|
||||
|
|
@ -365,7 +360,7 @@ static int __apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
|
|||
r.rel = &r.rel[1];
|
||||
}
|
||||
|
||||
err = handler(me, location, base, v, rela);
|
||||
err = reloc_handler(type, me, location, base, v, rela);
|
||||
if (err)
|
||||
goto out;
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue