diff options
Diffstat (limited to 'arch/parisc/kernel/module.c')
| -rw-r--r-- | arch/parisc/kernel/module.c | 304 |
1 files changed, 193 insertions, 111 deletions
diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c index fdacdd4341c..50dfafc3f2c 100644 --- a/arch/parisc/kernel/module.c +++ b/arch/parisc/kernel/module.c @@ -6,6 +6,7 @@ * * Linux/PA-RISC Project (http://www.parisc-linux.org/) * Copyright (C) 2003 Randolph Chung <tausq at debian . org> + * Copyright (C) 2008 Helge Deller <deller@gmx.de> * * * This program is free software; you can redistribute it and/or modify @@ -24,6 +25,19 @@ * * * Notes: + * - PLT stub handling + * On 32bit (and sometimes 64bit) and with big kernel modules like xfs or + * ipv6 the relocation types R_PARISC_PCREL17F and R_PARISC_PCREL22F may + * fail to reach their PLT stub if we only create one big stub array for + * all sections at the beginning of the core or init section. + * Instead we now insert individual PLT stub entries directly in front of + * of the code sections where the stubs are actually called. + * This reduces the distance between the PCREL location and the stub entry + * so that the relocations can be fulfilled. + * While calculating the final layout of the kernel module in memory, the + * kernel module loader calls arch_mod_section_prepend() to request the + * to be reserved amount of memory in front of each individual section. + * * - SEGREL32 handling * We are not doing SEGREL32 handling correctly. According to the ABI, we * should do a value offset, like this: @@ -47,7 +61,10 @@ #include <linux/string.h> #include <linux/kernel.h> #include <linux/bug.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <asm/pgtable.h> #include <asm/unwind.h> #if 0 @@ -56,9 +73,13 @@ #define DEBUGP(fmt...) #endif +#define RELOC_REACHABLE(val, bits) \ + (( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 ) || \ + ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \ + 0 : 1) + #define CHECK_RELOC(val, bits) \ - if ( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 ) || \ - ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) { \ + if (!RELOC_REACHABLE(val, bits)) { \ printk(KERN_ERR "module %s relocation of symbol %s is out of range (0x%lx in %d bits)\n", \ me->name, strtab + sym->st_name, (unsigned long)val, bits); \ return -ENOEXEC; \ @@ -68,8 +89,12 @@ * the bottom of the table, which has a maximum signed displacement of * 0x3fff; however, since we're only going forward, this becomes * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have - * at most 1023 entries */ -#define MAX_GOTS 1023 + * at most 1023 entries. + * To overcome this 14bit displacement with some kernel modules, we'll + * use instead the unusal 16bit displacement method (see reassemble_16a) + * which gives us a maximum positive displacement of 0x7fff, and as such + * allows us to allocate up to 4095 GOT entries. */ +#define MAX_GOTS 4095 /* three functions to determine where in the module core * or init pieces the location is */ @@ -90,20 +115,11 @@ static inline int in_local(struct module *me, void *loc) return in_init(me, loc) || in_core(me, loc); } -static inline int in_local_section(struct module *me, void *loc, void *dot) -{ - return (in_init(me, loc) && in_init(me, dot)) || - (in_core(me, loc) && in_core(me, dot)); -} - - #ifndef CONFIG_64BIT struct got_entry { Elf32_Addr addr; }; -#define Elf_Fdesc Elf32_Fdesc - struct stub_entry { Elf32_Word insns[2]; /* each stub entry has two insns */ }; @@ -112,8 +128,6 @@ struct got_entry { Elf64_Addr addr; }; -#define Elf_Fdesc Elf64_Fdesc - struct stub_entry { Elf64_Word insns[4]; /* each stub entry has four insns */ }; @@ -138,12 +152,40 @@ struct stub_entry { /* The reassemble_* functions prepare an immediate value for insertion into an opcode. pa-risc uses all sorts of weird bitfields in the instruction to hold the value. */ +static inline int sign_unext(int x, int len) +{ + int len_ones; + + len_ones = (1 << len) - 1; + return x & len_ones; +} + +static inline int low_sign_unext(int x, int len) +{ + int sign, temp; + + sign = (x >> (len-1)) & 1; + temp = sign_unext(x, len-1); + return (temp << 1) | sign; +} + static inline int reassemble_14(int as14) { return (((as14 & 0x1fff) << 1) | ((as14 & 0x2000) >> 13)); } +static inline int reassemble_16a(int as16) +{ + int s, t; + + /* Unusual 16-bit encoding, for wide mode only. */ + t = (as16 << 1) & 0xffff; + s = (as16 & 0x8000); + return (t ^ s ^ (s >> 1)) | (s >> 15); +} + + static inline int reassemble_17(int as17) { return (((as17 & 0x10000) >> 16) | @@ -172,9 +214,13 @@ static inline int reassemble_22(int as22) void *module_alloc(unsigned long size) { - if (size == 0) - return NULL; - return vmalloc(size); + /* using RWX means less protection for modules, but it's + * easier than trying to map the text, data, init_text and + * init_data correctly */ + return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, + GFP_KERNEL | __GFP_HIGHMEM, + PAGE_KERNEL_RWX, NUMA_NO_NODE, + __builtin_return_address(0)); } #ifndef CONFIG_64BIT @@ -256,9 +302,20 @@ static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n) /* Free memory returned from module_alloc */ void module_free(struct module *mod, void *module_region) { + kfree(mod->arch.section); + mod->arch.section = NULL; + vfree(module_region); - /* FIXME: If module_region == mod->init_region, trim exception - table entries. */ +} + +/* Additional bytes needed in front of individual sections */ +unsigned int arch_mod_section_prepend(struct module *mod, + unsigned int section) +{ + /* size needed for all stubs of this section (including + * one additional for correct alignment of the stubs) */ + return (mod->arch.section[section].stub_entries + 1) + * sizeof(struct stub_entry); } #define CONST @@ -267,12 +324,18 @@ int module_frob_arch_sections(CONST Elf_Ehdr *hdr, CONST char *secstrings, struct module *me) { - unsigned long gots = 0, fdescs = 0, stubs = 0, init_stubs = 0; + unsigned long gots = 0, fdescs = 0, len; unsigned int i; + len = hdr->e_shnum * sizeof(me->arch.section[0]); + me->arch.section = kzalloc(len, GFP_KERNEL); + if (!me->arch.section) + return -ENOMEM; + for (i = 1; i < hdr->e_shnum; i++) { - const Elf_Rela *rels = (void *)hdr + sechdrs[i].sh_offset; + const Elf_Rela *rels = (void *)sechdrs[i].sh_addr; unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels); + unsigned int count, s; if (strncmp(secstrings + sechdrs[i].sh_name, ".PARISC.unwind", 14) == 0) @@ -288,11 +351,23 @@ int module_frob_arch_sections(CONST Elf_Ehdr *hdr, */ gots += count_gots(rels, nrels); fdescs += count_fdescs(rels, nrels); - if(strncmp(secstrings + sechdrs[i].sh_name, - ".rela.init", 10) == 0) - init_stubs += count_stubs(rels, nrels); - else - stubs += count_stubs(rels, nrels); + + /* XXX: By sorting the relocs and finding duplicate entries + * we could reduce the number of necessary stubs and save + * some memory. */ + count = count_stubs(rels, nrels); + if (!count) + continue; + + /* so we need relocation stubs. reserve necessary memory. */ + /* sh_info gives the section for which we need to add stubs. */ + s = sechdrs[i].sh_info; + + /* each code section should only have one relocation section */ + WARN_ON(me->arch.section[s].stub_entries); + + /* store number of stubs we need for this section */ + me->arch.section[s].stub_entries += count; } /* align things a bit */ @@ -304,18 +379,8 @@ int module_frob_arch_sections(CONST Elf_Ehdr *hdr, me->arch.fdesc_offset = me->core_size; me->core_size += fdescs * sizeof(Elf_Fdesc); - me->core_size = ALIGN(me->core_size, 16); - me->arch.stub_offset = me->core_size; - me->core_size += stubs * sizeof(struct stub_entry); - - me->init_size = ALIGN(me->init_size, 16); - me->arch.init_stub_offset = me->init_size; - me->init_size += init_stubs * sizeof(struct stub_entry); - me->arch.got_max = gots; me->arch.fdesc_max = fdescs; - me->arch.stub_max = stubs; - me->arch.init_stub_max = init_stubs; return 0; } @@ -378,23 +443,28 @@ enum elf_stub_type { }; static Elf_Addr get_stub(struct module *me, unsigned long value, long addend, - enum elf_stub_type stub_type, int init_section) + enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec) { - unsigned long i; struct stub_entry *stub; - - if(init_section) { - i = me->arch.init_stub_count++; - BUG_ON(me->arch.init_stub_count > me->arch.init_stub_max); - stub = me->module_init + me->arch.init_stub_offset + - i * sizeof(struct stub_entry); - } else { - i = me->arch.stub_count++; - BUG_ON(me->arch.stub_count > me->arch.stub_max); - stub = me->module_core + me->arch.stub_offset + - i * sizeof(struct stub_entry); + int __maybe_unused d; + + /* initialize stub_offset to point in front of the section */ + if (!me->arch.section[targetsec].stub_offset) { + loc0 -= (me->arch.section[targetsec].stub_entries + 1) * + sizeof(struct stub_entry); + /* get correct alignment for the stubs */ + loc0 = ALIGN(loc0, sizeof(struct stub_entry)); + me->arch.section[targetsec].stub_offset = loc0; } + /* get address of stub entry */ + stub = (void *) me->arch.section[targetsec].stub_offset; + me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry); + + /* do not write outside available stub area */ + BUG_ON(0 == me->arch.section[targetsec].stub_entries--); + + #ifndef CONFIG_64BIT /* for 32-bit the stub looks like this: * ldil L'XXX,%r1 @@ -430,12 +500,19 @@ static Elf_Addr get_stub(struct module *me, unsigned long value, long addend, */ switch (stub_type) { case ELF_STUB_GOT: - stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp */ + d = get_got(me, value, addend); + if (d <= 15) { + /* Format 5 */ + stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp */ + stub->insns[0] |= low_sign_unext(d, 5) << 16; + } else { + /* Format 3 */ + stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp */ + stub->insns[0] |= reassemble_16a(d); + } stub->insns[1] = 0x53610020; /* ldd 10(%dp),%r1 */ stub->insns[2] = 0xe820d000; /* bve (%r1) */ stub->insns[3] = 0x537b0030; /* ldd 18(%dp),%dp */ - - stub->insns[0] |= reassemble_14(get_got(me, value, addend) & 0x3fff); break; case ELF_STUB_MILLI: stub->insns[0] = 0x20200000; /* ldil 0,%r1 */ @@ -461,18 +538,6 @@ static Elf_Addr get_stub(struct module *me, unsigned long value, long addend, return (Elf_Addr)stub; } -int apply_relocate(Elf_Shdr *sechdrs, - const char *strtab, - unsigned int symindex, - unsigned int relsec, - struct module *me) -{ - /* parisc should not need this ... */ - printk(KERN_ERR "module %s: RELOCATION unsupported\n", - me->name); - return -ENOEXEC; -} - #ifndef CONFIG_64BIT int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, @@ -487,15 +552,19 @@ int apply_relocate_add(Elf_Shdr *sechdrs, Elf32_Addr val; Elf32_Sword addend; Elf32_Addr dot; + Elf_Addr loc0; + unsigned int targetsec = sechdrs[relsec].sh_info; //unsigned long dp = (unsigned long)$global$; register unsigned long dp asm ("r27"); DEBUGP("Applying relocate section %u to %u\n", relsec, - sechdrs[relsec].sh_info); + targetsec); for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { /* This is where to make the change */ - loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + loc = (void *)sechdrs[targetsec].sh_addr + rel[i].r_offset; + /* This is the start of the target section */ + loc0 = sechdrs[targetsec].sh_addr; /* This is the symbol it is referring to */ sym = (Elf32_Sym *)sechdrs[symindex].sh_addr + ELF32_R_SYM(rel[i].r_info); @@ -567,19 +636,32 @@ int apply_relocate_add(Elf_Shdr *sechdrs, break; case R_PARISC_PCREL17F: /* 17-bit PC relative address */ - val = get_stub(me, val, addend, ELF_STUB_GOT, in_init(me, loc)); + /* calculate direct call offset */ + val += addend; val = (val - dot - 8)/4; - CHECK_RELOC(val, 17) + if (!RELOC_REACHABLE(val, 17)) { + /* direct distance too far, create + * stub entry instead */ + val = get_stub(me, sym->st_value, addend, + ELF_STUB_DIRECT, loc0, targetsec); + val = (val - dot - 8)/4; + CHECK_RELOC(val, 17); + } *loc = (*loc & ~0x1f1ffd) | reassemble_17(val); break; case R_PARISC_PCREL22F: /* 22-bit PC relative address; only defined for pa20 */ - val = get_stub(me, val, addend, ELF_STUB_GOT, in_init(me, loc)); - DEBUGP("STUB FOR %s loc %lx+%lx at %lx\n", - strtab + sym->st_name, (unsigned long)loc, addend, - val) + /* calculate direct call offset */ + val += addend; val = (val - dot - 8)/4; - CHECK_RELOC(val, 22); + if (!RELOC_REACHABLE(val, 22)) { + /* direct distance too far, create + * stub entry instead */ + val = get_stub(me, sym->st_value, addend, + ELF_STUB_DIRECT, loc0, targetsec); + val = (val - dot - 8)/4; + CHECK_RELOC(val, 22); + } *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val); break; @@ -608,13 +690,17 @@ int apply_relocate_add(Elf_Shdr *sechdrs, Elf64_Addr val; Elf64_Sxword addend; Elf64_Addr dot; + Elf_Addr loc0; + unsigned int targetsec = sechdrs[relsec].sh_info; DEBUGP("Applying relocate section %u to %u\n", relsec, - sechdrs[relsec].sh_info); + targetsec); for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { /* This is where to make the change */ - loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + loc = (void *)sechdrs[targetsec].sh_addr + rel[i].r_offset; + /* This is the start of the target section */ + loc0 = sechdrs[targetsec].sh_addr; /* This is the symbol it is referring to */ sym = (Elf64_Sym *)sechdrs[symindex].sh_addr + ELF64_R_SYM(rel[i].r_info); @@ -670,42 +756,40 @@ int apply_relocate_add(Elf_Shdr *sechdrs, DEBUGP("PCREL22F Symbol %s loc %p val %lx\n", strtab + sym->st_name, loc, val); + val += addend; /* can we reach it locally? */ - if(!in_local_section(me, (void *)val, (void *)dot)) { - - if (in_local(me, (void *)val)) - /* this is the case where the - * symbol is local to the - * module, but in a different - * section, so stub the jump - * in case it's more than 22 - * bits away */ - val = get_stub(me, val, addend, ELF_STUB_DIRECT, - in_init(me, loc)); - else if (strncmp(strtab + sym->st_name, "$$", 2) + if (in_local(me, (void *)val)) { + /* this is the case where the symbol is local + * to the module, but in a different section, + * so stub the jump in case it's more than 22 + * bits away */ + val = (val - dot - 8)/4; + if (!RELOC_REACHABLE(val, 22)) { + /* direct distance too far, create + * stub entry instead */ + val = get_stub(me, sym->st_value, + addend, ELF_STUB_DIRECT, + loc0, targetsec); + } else { + /* Ok, we can reach it directly. */ + val = sym->st_value; + val += addend; + } + } else { + val = sym->st_value; + if (strncmp(strtab + sym->st_name, "$$", 2) == 0) val = get_stub(me, val, addend, ELF_STUB_MILLI, - in_init(me, loc)); + loc0, targetsec); else val = get_stub(me, val, addend, ELF_STUB_GOT, - in_init(me, loc)); + loc0, targetsec); } DEBUGP("STUB FOR %s loc %lx, val %lx+%lx at %lx\n", strtab + sym->st_name, loc, sym->st_value, addend, val); - /* FIXME: local symbols work as long as the - * core and init pieces aren't separated too - * far. If this is ever broken, you will trip - * the check below. The way to fix it would - * be to generate local stubs to go between init - * and core */ - if((Elf64_Sxword)(val - dot - 8) > 0x800000 -1 || - (Elf64_Sxword)(val - dot - 8) < -0x800000) { - printk(KERN_ERR "Module %s, symbol %s is out of range for PCREL22F relocation\n", - me->name, strtab + sym->st_name); - return -ENOEXEC; - } val = (val - dot - 8)/4; + CHECK_RELOC(val, 22); *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val); break; case R_PARISC_DIR64: @@ -792,12 +876,8 @@ int module_finalize(const Elf_Ehdr *hdr, addr = (u32 *)entry->addr; printk("INSNS: %x %x %x %x\n", addr[0], addr[1], addr[2], addr[3]); - printk("stubs used %ld, stubs max %ld\n" - "init_stubs used %ld, init stubs max %ld\n" - "got entries used %ld, gots max %ld\n" + printk("got entries used %ld, gots max %ld\n" "fdescs used %ld, fdescs max %ld\n", - me->arch.stub_count, me->arch.stub_max, - me->arch.init_stub_count, me->arch.init_stub_max, me->arch.got_count, me->arch.got_max, me->arch.fdesc_count, me->arch.fdesc_max); #endif @@ -808,7 +888,7 @@ int module_finalize(const Elf_Ehdr *hdr, * ourselves */ for (i = 1; i < hdr->e_shnum; i++) { if(sechdrs[i].sh_type == SHT_SYMTAB - && (sechdrs[i].sh_type & SHF_ALLOC)) { + && (sechdrs[i].sh_flags & SHF_ALLOC)) { int strindex = sechdrs[i].sh_link; /* FIXME: AWFUL HACK * The cast is to drop the const from @@ -827,7 +907,10 @@ int module_finalize(const Elf_Ehdr *hdr, me->name, me->arch.got_count, MAX_GOTS); return -EINVAL; } - + + kfree(me->arch.section); + me->arch.section = NULL; + /* no symbol table */ if(symhdr == NULL) return 0; @@ -852,11 +935,10 @@ int module_finalize(const Elf_Ehdr *hdr, nsyms = newptr - (Elf_Sym *)symhdr->sh_addr; DEBUGP("NEW num_symtab %lu\n", nsyms); symhdr->sh_size = nsyms * sizeof(Elf_Sym); - return module_bug_finalize(hdr, sechdrs, me); + return 0; } void module_arch_cleanup(struct module *mod) { deregister_unwind_table(mod); - module_bug_cleanup(mod); } |