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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#include <linux/moduleloader.h>#include <linux/elf.h>#include <linux/fs.h>#include <linux/ftrace.h>#include <linux/string.h>#include <linux/kernel.h>#include <linux/bug.h>#include <linux/mm.h>#include <linux/slab.h>
#include <asm/unwind.h>#include <asm/sections.h>
#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 (!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; \ }
/* Maximum number of GOT entries. We use a long displacement ldd from * 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. * 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
#ifndef CONFIG_64BITstruct got_entry { Elf32_Addr addr;};
struct stub_entry { Elf32_Word insns[2]; /* each stub entry has two insns */};#elsestruct got_entry { Elf64_Addr addr;};
struct stub_entry { Elf64_Word insns[4]; /* each stub entry has four insns */};#endif
/* Field selection types defined by hppa */#define rnd(x) (((x)+0x1000)&~0x1fff)/* fsel: full 32 bits */#define fsel(v,a) ((v)+(a))/* lsel: select left 21 bits */#define lsel(v,a) (((v)+(a))>>11)/* rsel: select right 11 bits */#define rsel(v,a) (((v)+(a))&0x7ff)/* lrsel with rounding of addend to nearest 8k */#define lrsel(v,a) (((v)+rnd(a))>>11)/* rrsel with rounding of addend to nearest 8k */#define rrsel(v,a) ((((v)+rnd(a))&0x7ff)+((a)-rnd(a)))
#define mask(x,sz) ((x) & ~((1<<(sz))-1))
/* 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) | ((as17 & 0x0f800) << 5) | ((as17 & 0x00400) >> 8) | ((as17 & 0x003ff) << 3));}
static inline int reassemble_21(int as21){ return (((as21 & 0x100000) >> 20) | ((as21 & 0x0ffe00) >> 8) | ((as21 & 0x000180) << 7) | ((as21 & 0x00007c) << 14) | ((as21 & 0x000003) << 12));}
static inline int reassemble_22(int as22){ return (((as22 & 0x200000) >> 21) | ((as22 & 0x1f0000) << 5) | ((as22 & 0x00f800) << 5) | ((as22 & 0x000400) >> 8) | ((as22 & 0x0003ff) << 3));}
#ifndef CONFIG_64BITstatic inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n){ return 0;}
static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n){ return 0;}
static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n){ unsigned long cnt = 0;
for (; n > 0; n--, rela++) { switch (ELF32_R_TYPE(rela->r_info)) { case R_PARISC_PCREL17F: case R_PARISC_PCREL22F: cnt++; } }
return cnt;}#elsestatic inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n){ unsigned long cnt = 0;
for (; n > 0; n--, rela++) { switch (ELF64_R_TYPE(rela->r_info)) { case R_PARISC_LTOFF21L: case R_PARISC_LTOFF14R: case R_PARISC_PCREL22F: cnt++; } }
return cnt;}
static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n){ unsigned long cnt = 0;
for (; n > 0; n--, rela++) { switch (ELF64_R_TYPE(rela->r_info)) { case R_PARISC_FPTR64: cnt++; } }
return cnt;}
static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n){ unsigned long cnt = 0;
for (; n > 0; n--, rela++) { switch (ELF64_R_TYPE(rela->r_info)) { case R_PARISC_PCREL22F: cnt++; } }
return cnt;}#endif
void module_arch_freeing_init(struct module *mod){ kfree(mod->arch.section); mod->arch.section = NULL;}
/* 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 CONSTint module_frob_arch_sections(CONST Elf_Ehdr *hdr, CONST Elf_Shdr *sechdrs, CONST char *secstrings, struct module *me){ unsigned long gots = 0, fdescs = 0, len; unsigned int i; struct module_memory *mod_mem;
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 *)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) me->arch.unwind_section = i;
if (sechdrs[i].sh_type != SHT_RELA) continue;
/* some of these are not relevant for 32-bit/64-bit * we leave them here to make the code common. the * compiler will do its thing and optimize out the * stuff we don't need */ gots += count_gots(rels, nrels); fdescs += count_fdescs(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; }
mod_mem = &me->mem[MOD_TEXT]; /* align things a bit */ mod_mem->size = ALIGN(mod_mem->size, 16); me->arch.got_offset = mod_mem->size; mod_mem->size += gots * sizeof(struct got_entry);
mod_mem->size = ALIGN(mod_mem->size, 16); me->arch.fdesc_offset = mod_mem->size; mod_mem->size += fdescs * sizeof(Elf_Fdesc);
me->arch.got_max = gots; me->arch.fdesc_max = fdescs;
return 0;}
#ifdef CONFIG_64BITstatic Elf64_Word get_got(struct module *me, unsigned long value, long addend){ unsigned int i; struct got_entry *got;
value += addend;
BUG_ON(value == 0);
got = me->mem[MOD_TEXT].base + me->arch.got_offset; for (i = 0; got[i].addr; i++) if (got[i].addr == value) goto out;
BUG_ON(++me->arch.got_count > me->arch.got_max);
got[i].addr = value; out: pr_debug("GOT ENTRY %d[%lx] val %lx\n", i, i*sizeof(struct got_entry), value); return i * sizeof(struct got_entry);}#endif /* CONFIG_64BIT */
#ifdef CONFIG_64BITstatic Elf_Addr get_fdesc(struct module *me, unsigned long value){ Elf_Fdesc *fdesc = me->mem[MOD_TEXT].base + me->arch.fdesc_offset;
if (!value) { printk(KERN_ERR "%s: zero OPD requested!\n", me->name); return 0; }
/* Look for existing fdesc entry. */ while (fdesc->addr) { if (fdesc->addr == value) return (Elf_Addr)fdesc; fdesc++; }
BUG_ON(++me->arch.fdesc_count > me->arch.fdesc_max);
/* Create new one */ fdesc->addr = value; fdesc->gp = (Elf_Addr)me->mem[MOD_TEXT].base + me->arch.got_offset; return (Elf_Addr)fdesc;}#endif /* CONFIG_64BIT */
enum elf_stub_type { ELF_STUB_GOT, ELF_STUB_MILLI, ELF_STUB_DIRECT,};
static Elf_Addr get_stub(struct module *me, unsigned long value, long addend, enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec){ struct stub_entry *stub; 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 * be,n R'XXX(%sr4,%r1) */ //value = *(unsigned long *)((value + addend) & ~3); /* why? */
stub->insns[0] = 0x20200000; /* ldil L'XXX,%r1 */ stub->insns[1] = 0xe0202002; /* be,n R'XXX(%sr4,%r1) */
stub->insns[0] |= reassemble_21(lrsel(value, addend)); stub->insns[1] |= reassemble_17(rrsel(value, addend) / 4);
#else/* for 64-bit we have three kinds of stubs: * for normal function calls: * ldd 0(%dp),%dp * ldd 10(%dp), %r1 * bve (%r1) * ldd 18(%dp), %dp * * for millicode: * ldil 0, %r1 * ldo 0(%r1), %r1 * ldd 10(%r1), %r1 * bve,n (%r1) * * for direct branches (jumps between different section of the * same module): * ldil 0, %r1 * ldo 0(%r1), %r1 * bve,n (%r1) */ switch (stub_type) { case ELF_STUB_GOT: 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 */ break; case ELF_STUB_MILLI: stub->insns[0] = 0x20200000; /* ldil 0,%r1 */ stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */ stub->insns[2] = 0x50210020; /* ldd 10(%r1),%r1 */ stub->insns[3] = 0xe820d002; /* bve,n (%r1) */
stub->insns[0] |= reassemble_21(lrsel(value, addend)); stub->insns[1] |= reassemble_14(rrsel(value, addend)); break; case ELF_STUB_DIRECT: stub->insns[0] = 0x20200000; /* ldil 0,%r1 */ stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */ stub->insns[2] = 0xe820d002; /* bve,n (%r1) */
stub->insns[0] |= reassemble_21(lrsel(value, addend)); stub->insns[1] |= reassemble_14(rrsel(value, addend)); break; }
#endif
return (Elf_Addr)stub;}
#ifndef CONFIG_64BITint apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *me){ int i; Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr; Elf32_Sym *sym; Elf32_Word *loc; 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");
pr_debug("Applying relocate section %u to %u\n", relsec, targetsec); for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { /* This is where to make the change */ 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); if (!sym->st_value) { printk(KERN_WARNING "%s: Unknown symbol %s\n", me->name, strtab + sym->st_name); return -ENOENT; } //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03; dot = (Elf32_Addr)loc & ~0x03;
val = sym->st_value; addend = rel[i].r_addend;
#if 0#define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t : pr_debug("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n", strtab + sym->st_name, (uint32_t)loc, val, addend, r(R_PARISC_PLABEL32) r(R_PARISC_DIR32) r(R_PARISC_DIR21L) r(R_PARISC_DIR14R) r(R_PARISC_SEGREL32) r(R_PARISC_DPREL21L) r(R_PARISC_DPREL14R) r(R_PARISC_PCREL17F) r(R_PARISC_PCREL22F) "UNKNOWN");#undef r#endif
switch (ELF32_R_TYPE(rel[i].r_info)) { case R_PARISC_PLABEL32: /* 32-bit function address */ /* no function descriptors... */ *loc = fsel(val, addend); break; case R_PARISC_DIR32: /* direct 32-bit ref */ *loc = fsel(val, addend); break; case R_PARISC_DIR21L: /* left 21 bits of effective address */ val = lrsel(val, addend); *loc = mask(*loc, 21) | reassemble_21(val); break; case R_PARISC_DIR14R: /* right 14 bits of effective address */ val = rrsel(val, addend); *loc = mask(*loc, 14) | reassemble_14(val); break; case R_PARISC_SEGREL32: /* 32-bit segment relative address */ /* See note about special handling of SEGREL32 at * the beginning of this file. */ *loc = fsel(val, addend); break; case R_PARISC_SECREL32: /* 32-bit section relative address. */ *loc = fsel(val, addend); break; case R_PARISC_DPREL21L: /* left 21 bit of relative address */ val = lrsel(val - dp, addend); *loc = mask(*loc, 21) | reassemble_21(val); break; case R_PARISC_DPREL14R: /* right 14 bit of relative address */ val = rrsel(val - dp, addend); *loc = mask(*loc, 14) | reassemble_14(val); break; case R_PARISC_PCREL17F: /* 17-bit PC relative address */ /* calculate direct call offset */ val += addend; val = (val - dot - 8)/4; 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 */ /* calculate direct call offset */ val += addend; 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); val = (val - dot - 8)/4; CHECK_RELOC(val, 22); } *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val); break; case R_PARISC_PCREL32: /* 32-bit PC relative address */ *loc = val - dot - 8 + addend; break;
default: printk(KERN_ERR "module %s: Unknown relocation: %u\n", me->name, ELF32_R_TYPE(rel[i].r_info)); return -ENOEXEC; } }
return 0;}
#elseint apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *me){ int i; Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr; Elf64_Sym *sym; Elf64_Word *loc; Elf64_Xword *loc64; Elf64_Addr val; Elf64_Sxword addend; Elf64_Addr dot; Elf_Addr loc0; unsigned int targetsec = sechdrs[relsec].sh_info;
pr_debug("Applying relocate section %u to %u\n", relsec, targetsec); for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { /* This is where to make the change */ 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); if (!sym->st_value) { printk(KERN_WARNING "%s: Unknown symbol %s\n", me->name, strtab + sym->st_name); return -ENOENT; } //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03; dot = (Elf64_Addr)loc & ~0x03; loc64 = (Elf64_Xword *)loc;
val = sym->st_value; addend = rel[i].r_addend;
#if 0#define r(t) ELF64_R_TYPE(rel[i].r_info)==t ? #t : printk("Symbol %s loc %p val 0x%Lx addend 0x%Lx: %s\n", strtab + sym->st_name, loc, val, addend, r(R_PARISC_LTOFF14R) r(R_PARISC_LTOFF21L) r(R_PARISC_PCREL22F) r(R_PARISC_DIR64) r(R_PARISC_SEGREL32) r(R_PARISC_FPTR64) "UNKNOWN");#undef r#endif
switch (ELF64_R_TYPE(rel[i].r_info)) { case R_PARISC_LTOFF21L: /* LT-relative; left 21 bits */ val = get_got(me, val, addend); pr_debug("LTOFF21L Symbol %s loc %p val %llx\n", strtab + sym->st_name, loc, val); val = lrsel(val, 0); *loc = mask(*loc, 21) | reassemble_21(val); break; case R_PARISC_LTOFF14R: /* L(ltoff(val+addend)) */ /* LT-relative; right 14 bits */ val = get_got(me, val, addend); val = rrsel(val, 0); pr_debug("LTOFF14R Symbol %s loc %p val %llx\n", strtab + sym->st_name, loc, val); *loc = mask(*loc, 14) | reassemble_14(val); break; case R_PARISC_PCREL22F: /* PC-relative; 22 bits */ pr_debug("PCREL22F Symbol %s loc %p val %llx\n", strtab + sym->st_name, loc, val); val += addend; /* can we reach it locally? */ if (within_module(val, me)) { /* 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, loc0, targetsec); else val = get_stub(me, val, addend, ELF_STUB_GOT, loc0, targetsec); } pr_debug("STUB FOR %s loc %px, val %llx+%llx at %llx\n", strtab + sym->st_name, loc, sym->st_value, addend, val); val = (val - dot - 8)/4; CHECK_RELOC(val, 22); *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val); break; case R_PARISC_PCREL32: /* 32-bit PC relative address */ *loc = val - dot - 8 + addend; break; case R_PARISC_PCREL64: /* 64-bit PC relative address */ *loc64 = val - dot - 8 + addend; break; case R_PARISC_DIR64: /* 64-bit effective address */ *loc64 = val + addend; break; case R_PARISC_SEGREL32: /* 32-bit segment relative address */ /* See note about special handling of SEGREL32 at * the beginning of this file. */ *loc = fsel(val, addend); break; case R_PARISC_SECREL32: /* 32-bit section relative address. */ *loc = fsel(val, addend); break; case R_PARISC_FPTR64: /* 64-bit function address */ if (within_module(val + addend, me)) { *loc64 = get_fdesc(me, val+addend); pr_debug("FDESC for %s at %llx points to %llx\n", strtab + sym->st_name, *loc64, ((Elf_Fdesc *)*loc64)->addr); } else { /* if the symbol is not local to this * module then val+addend is a pointer * to the function descriptor */ pr_debug("Non local FPTR64 Symbol %s loc %p val %llx\n", strtab + sym->st_name, loc, val); *loc64 = val + addend; } break;
default: printk(KERN_ERR "module %s: Unknown relocation: %Lu\n", me->name, ELF64_R_TYPE(rel[i].r_info)); return -ENOEXEC; } } return 0;}#endif
static voidregister_unwind_table(struct module *me, const Elf_Shdr *sechdrs){ unsigned char *table, *end; unsigned long gp;
if (!me->arch.unwind_section) return;
table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr; end = table + sechdrs[me->arch.unwind_section].sh_size; gp = (Elf_Addr)me->mem[MOD_TEXT].base + me->arch.got_offset;
pr_debug("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n", me->arch.unwind_section, table, end, gp); me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end);}
static voidderegister_unwind_table(struct module *me){ if (me->arch.unwind) unwind_table_remove(me->arch.unwind);}
int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me){ int i; unsigned long nsyms; const char *strtab = NULL; const Elf_Shdr *s; char *secstrings; int symindex __maybe_unused = -1; Elf_Sym *newptr, *oldptr; Elf_Shdr *symhdr = NULL;#ifdef DEBUG Elf_Fdesc *entry; u32 *addr;
entry = (Elf_Fdesc *)me->init; printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry, entry->gp, entry->addr); addr = (u32 *)entry->addr; printk("INSNS: %x %x %x %x\n", addr[0], addr[1], addr[2], addr[3]); printk("got entries used %ld, gots max %ld\n" "fdescs used %ld, fdescs max %ld\n", me->arch.got_count, me->arch.got_max, me->arch.fdesc_count, me->arch.fdesc_max);#endif
register_unwind_table(me, sechdrs);
/* haven't filled in me->symtab yet, so have to find it * ourselves */ for (i = 1; i < hdr->e_shnum; i++) { if(sechdrs[i].sh_type == SHT_SYMTAB && (sechdrs[i].sh_flags & SHF_ALLOC)) { int strindex = sechdrs[i].sh_link; symindex = i; /* FIXME: AWFUL HACK * The cast is to drop the const from * the sechdrs pointer */ symhdr = (Elf_Shdr *)&sechdrs[i]; strtab = (char *)sechdrs[strindex].sh_addr; break; } }
pr_debug("module %s: strtab %p, symhdr %p\n", me->name, strtab, symhdr);
if(me->arch.got_count > MAX_GOTS) { printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n", 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;
oldptr = (void *)symhdr->sh_addr; newptr = oldptr + 1; /* we start counting at 1 */ nsyms = symhdr->sh_size / sizeof(Elf_Sym); pr_debug("OLD num_symtab %lu\n", nsyms);
for (i = 1; i < nsyms; i++) { oldptr++; /* note, count starts at 1 so preincrement */ if(strncmp(strtab + oldptr->st_name, ".L", 2) == 0) continue;
if(newptr != oldptr) *newptr++ = *oldptr; else newptr++;
} nsyms = newptr - (Elf_Sym *)symhdr->sh_addr; pr_debug("NEW num_symtab %lu\n", nsyms); symhdr->sh_size = nsyms * sizeof(Elf_Sym);
/* find .altinstructions section */ secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { void *aseg = (void *) s->sh_addr; char *secname = secstrings + s->sh_name;
if (!strcmp(".altinstructions", secname)) /* patch .altinstructions */ apply_alternatives(aseg, aseg + s->sh_size, me->name);
#ifdef CONFIG_DYNAMIC_FTRACE /* For 32 bit kernels we're compiling modules with * -ffunction-sections so we must relocate the addresses in the * ftrace callsite section. */ if (symindex != -1 && !strcmp(secname, FTRACE_CALLSITE_SECTION)) { int err; if (s->sh_type == SHT_REL) err = apply_relocate((Elf_Shdr *)sechdrs, strtab, symindex, s - sechdrs, me); else if (s->sh_type == SHT_RELA) err = apply_relocate_add((Elf_Shdr *)sechdrs, strtab, symindex, s - sechdrs, me); if (err) return err; }#endif } return 0;}
void module_arch_cleanup(struct module *mod){ deregister_unwind_table(mod);}
#ifdef CONFIG_64BITvoid *dereference_module_function_descriptor(struct module *mod, void *ptr){ unsigned long start_opd = (Elf64_Addr)mod->mem[MOD_TEXT].base + mod->arch.fdesc_offset; unsigned long end_opd = start_opd + mod->arch.fdesc_count * sizeof(Elf64_Fdesc);
if (ptr < (void *)start_opd || ptr >= (void *)end_opd) return ptr;
return dereference_function_descriptor(ptr);}#endif