| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* Kernel dynamically loadable module help for PARISC. |
| * |
| * The best reference for this stuff is probably the Processor- |
| * Specific ELF Supplement for PA-RISC: |
| * http://ftp.parisc-linux.org/docs/arch/elf-pa-hp.pdf |
| * |
| * 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> |
| * |
| * 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: |
| * if (in_init(me, (void *)val)) |
| * val -= (uint32_t)me->init_layout.base; |
| * else |
| * val -= (uint32_t)me->core_layout.base; |
| * However, SEGREL32 is used only for PARISC unwind entries, and we want |
| * those entries to have an absolute address, and not just an offset. |
| * |
| * The unwind table mechanism has the ability to specify an offset for |
| * the unwind table; however, because we split off the init functions into |
| * a different piece of memory, it is not possible to do this using a |
| * single offset. Instead, we use the above hack for now. |
| */ |
| |
| #include <linux/moduleloader.h> |
| #include <linux/elf.h> |
| #include <linux/vmalloc.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/pgtable.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 |
| |
| /* three functions to determine where in the module core |
| * or init pieces the location is */ |
| static inline int in_init(struct module *me, void *loc) |
| { |
| return (loc >= me->init_layout.base && |
| loc <= (me->init_layout.base + me->init_layout.size)); |
| } |
| |
| static inline int in_core(struct module *me, void *loc) |
| { |
| return (loc >= me->core_layout.base && |
| loc <= (me->core_layout.base + me->core_layout.size)); |
| } |
| |
| static inline int in_local(struct module *me, void *loc) |
| { |
| return in_init(me, loc) || in_core(me, loc); |
| } |
| |
| #ifndef CONFIG_64BIT |
| struct got_entry { |
| Elf32_Addr addr; |
| }; |
| |
| struct stub_entry { |
| Elf32_Word insns[2]; /* each stub entry has two insns */ |
| }; |
| #else |
| struct 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)); |
| } |
| |
| void *module_alloc(unsigned long 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, |
| PAGE_KERNEL_RWX, 0, NUMA_NO_NODE, |
| __builtin_return_address(0)); |
| } |
| |
| #ifndef CONFIG_64BIT |
| static 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; |
| } |
| #else |
| static 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 CONST |
| int 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; |
| |
| 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; |
| } |
| |
| /* align things a bit */ |
| me->core_layout.size = ALIGN(me->core_layout.size, 16); |
| me->arch.got_offset = me->core_layout.size; |
| me->core_layout.size += gots * sizeof(struct got_entry); |
| |
| me->core_layout.size = ALIGN(me->core_layout.size, 16); |
| me->arch.fdesc_offset = me->core_layout.size; |
| me->core_layout.size += fdescs * sizeof(Elf_Fdesc); |
| |
| me->arch.got_max = gots; |
| me->arch.fdesc_max = fdescs; |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_64BIT |
| static 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->core_layout.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_64BIT |
| static Elf_Addr get_fdesc(struct module *me, unsigned long value) |
| { |
| Elf_Fdesc *fdesc = me->core_layout.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->core_layout.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_64BIT |
| int 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; |
| } |
| |
| #else |
| int 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 (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, |
| 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(in_local(me, (void *)(val + addend))) { |
| *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 void |
| register_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->core_layout.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 void |
| deregister_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 = -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_64BIT |
| void *dereference_module_function_descriptor(struct module *mod, void *ptr) |
| { |
| unsigned long start_opd = (Elf64_Addr)mod->core_layout.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 |