diff options
Diffstat (limited to 'arch/arm64/kernel/module.c')
-rw-r--r-- | arch/arm64/kernel/module.c | 96 |
1 files changed, 46 insertions, 50 deletions
diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c index f4bc779e62e8..7f316982ce00 100644 --- a/arch/arm64/kernel/module.c +++ b/arch/arm64/kernel/module.c @@ -30,17 +30,30 @@ #include <asm/insn.h> #include <asm/sections.h> -#define AARCH64_INSN_IMM_MOVNZ AARCH64_INSN_IMM_MAX -#define AARCH64_INSN_IMM_MOVK AARCH64_INSN_IMM_16 - void *module_alloc(unsigned long size) { void *p; - p = __vmalloc_node_range(size, MODULE_ALIGN, MODULES_VADDR, MODULES_END, + p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base, + module_alloc_base + MODULES_VSIZE, GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE, __builtin_return_address(0)); + if (!p && IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) && + !IS_ENABLED(CONFIG_KASAN)) + /* + * KASAN can only deal with module allocations being served + * from the reserved module region, since the remainder of + * the vmalloc region is already backed by zero shadow pages, + * and punching holes into it is non-trivial. Since the module + * region is not randomized when KASAN is enabled, it is even + * less likely that the module region gets exhausted, so we + * can simply omit this fallback in that case. + */ + p = __vmalloc_node_range(size, MODULE_ALIGN, VMALLOC_START, + VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_EXEC, 0, + NUMA_NO_NODE, __builtin_return_address(0)); + if (p && (kasan_module_alloc(p, size) < 0)) { vfree(p); return NULL; @@ -75,15 +88,18 @@ static u64 do_reloc(enum aarch64_reloc_op reloc_op, void *place, u64 val) static int reloc_data(enum aarch64_reloc_op op, void *place, u64 val, int len) { - u64 imm_mask = (1 << len) - 1; s64 sval = do_reloc(op, place, val); switch (len) { case 16: *(s16 *)place = sval; + if (sval < S16_MIN || sval > U16_MAX) + return -ERANGE; break; case 32: *(s32 *)place = sval; + if (sval < S32_MIN || sval > U32_MAX) + return -ERANGE; break; case 64: *(s64 *)place = sval; @@ -92,34 +108,23 @@ static int reloc_data(enum aarch64_reloc_op op, void *place, u64 val, int len) pr_err("Invalid length (%d) for data relocation\n", len); return 0; } - - /* - * Extract the upper value bits (including the sign bit) and - * shift them to bit 0. - */ - sval = (s64)(sval & ~(imm_mask >> 1)) >> (len - 1); - - /* - * Overflow has occurred if the value is not representable in - * len bits (i.e the bottom len bits are not sign-extended and - * the top bits are not all zero). - */ - if ((u64)(sval + 1) > 2) - return -ERANGE; - return 0; } +enum aarch64_insn_movw_imm_type { + AARCH64_INSN_IMM_MOVNZ, + AARCH64_INSN_IMM_MOVKZ, +}; + static int reloc_insn_movw(enum aarch64_reloc_op op, void *place, u64 val, - int lsb, enum aarch64_insn_imm_type imm_type) + int lsb, enum aarch64_insn_movw_imm_type imm_type) { - u64 imm, limit = 0; + u64 imm; s64 sval; u32 insn = le32_to_cpu(*(u32 *)place); sval = do_reloc(op, place, val); - sval >>= lsb; - imm = sval & 0xffff; + imm = sval >> lsb; if (imm_type == AARCH64_INSN_IMM_MOVNZ) { /* @@ -128,7 +133,7 @@ static int reloc_insn_movw(enum aarch64_reloc_op op, void *place, u64 val, * immediate is less than zero. */ insn &= ~(3 << 29); - if ((s64)imm >= 0) { + if (sval >= 0) { /* >=0: Set the instruction to MOVZ (opcode 10b). */ insn |= 2 << 29; } else { @@ -140,29 +145,13 @@ static int reloc_insn_movw(enum aarch64_reloc_op op, void *place, u64 val, */ imm = ~imm; } - imm_type = AARCH64_INSN_IMM_MOVK; } /* Update the instruction with the new encoding. */ - insn = aarch64_insn_encode_immediate(imm_type, insn, imm); + insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_16, insn, imm); *(u32 *)place = cpu_to_le32(insn); - /* Shift out the immediate field. */ - sval >>= 16; - - /* - * For unsigned immediates, the overflow check is straightforward. - * For signed immediates, the sign bit is actually the bit past the - * most significant bit of the field. - * The AARCH64_INSN_IMM_16 immediate type is unsigned. - */ - if (imm_type != AARCH64_INSN_IMM_16) { - sval++; - limit++; - } - - /* Check the upper bits depending on the sign of the immediate. */ - if ((u64)sval > limit) + if (imm > U16_MAX) return -ERANGE; return 0; @@ -267,25 +256,25 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, overflow_check = false; case R_AARCH64_MOVW_UABS_G0: ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 0, - AARCH64_INSN_IMM_16); + AARCH64_INSN_IMM_MOVKZ); break; case R_AARCH64_MOVW_UABS_G1_NC: overflow_check = false; case R_AARCH64_MOVW_UABS_G1: ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 16, - AARCH64_INSN_IMM_16); + AARCH64_INSN_IMM_MOVKZ); break; case R_AARCH64_MOVW_UABS_G2_NC: overflow_check = false; case R_AARCH64_MOVW_UABS_G2: ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 32, - AARCH64_INSN_IMM_16); + AARCH64_INSN_IMM_MOVKZ); break; case R_AARCH64_MOVW_UABS_G3: /* We're using the top bits so we can't overflow. */ overflow_check = false; ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 48, - AARCH64_INSN_IMM_16); + AARCH64_INSN_IMM_MOVKZ); break; case R_AARCH64_MOVW_SABS_G0: ovf = reloc_insn_movw(RELOC_OP_ABS, loc, val, 0, @@ -302,7 +291,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, case R_AARCH64_MOVW_PREL_G0_NC: overflow_check = false; ovf = reloc_insn_movw(RELOC_OP_PREL, loc, val, 0, - AARCH64_INSN_IMM_MOVK); + AARCH64_INSN_IMM_MOVKZ); break; case R_AARCH64_MOVW_PREL_G0: ovf = reloc_insn_movw(RELOC_OP_PREL, loc, val, 0, @@ -311,7 +300,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, case R_AARCH64_MOVW_PREL_G1_NC: overflow_check = false; ovf = reloc_insn_movw(RELOC_OP_PREL, loc, val, 16, - AARCH64_INSN_IMM_MOVK); + AARCH64_INSN_IMM_MOVKZ); break; case R_AARCH64_MOVW_PREL_G1: ovf = reloc_insn_movw(RELOC_OP_PREL, loc, val, 16, @@ -320,7 +309,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, case R_AARCH64_MOVW_PREL_G2_NC: overflow_check = false; ovf = reloc_insn_movw(RELOC_OP_PREL, loc, val, 32, - AARCH64_INSN_IMM_MOVK); + AARCH64_INSN_IMM_MOVKZ); break; case R_AARCH64_MOVW_PREL_G2: ovf = reloc_insn_movw(RELOC_OP_PREL, loc, val, 32, @@ -388,6 +377,13 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, case R_AARCH64_CALL26: ovf = reloc_insn_imm(RELOC_OP_PREL, loc, val, 2, 26, AARCH64_INSN_IMM_26); + + if (IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) && + ovf == -ERANGE) { + val = module_emit_plt_entry(me, &rel[i], sym); + ovf = reloc_insn_imm(RELOC_OP_PREL, loc, val, 2, + 26, AARCH64_INSN_IMM_26); + } break; default: |