| Message ID | 20210116150225.21127-1-alobakin@pm.me (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 049a68efbf0bb29d012f2d73b91c674ca2d805fe |
| Headers | show |
| Series | MIPS: optimize relocations processing | expand |
在 2021/1/16 下午11:02, Alexander Lobakin 写道: > 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> > --- > arch/mips/kernel/module.c | 109 ++++++++++++++++++-------------------- > 1 file changed, 52 insertions(+), 57 deletions(-) > > diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c > index 3c0c3d1260c1..14f46d17500a 100644 > --- a/arch/mips/kernel/module.c > +++ b/arch/mips/kernel/module.c > @@ -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); > - > -/* 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, > -}; > +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; > + } > + > + 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; > }
diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c index 3c0c3d1260c1..14f46d17500a 100644 --- a/arch/mips/kernel/module.c +++ b/arch/mips/kernel/module.c @@ -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); - -/* 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, -}; +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; + } + + 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; }
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> --- arch/mips/kernel/module.c | 109 ++++++++++++++++++-------------------- 1 file changed, 52 insertions(+), 57 deletions(-)