diff options
Diffstat (limited to 'arch/x86/lib')
| -rw-r--r-- | arch/x86/lib/insn-eval.c | 60 |
1 files changed, 55 insertions, 5 deletions
diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c index e6cb68a4f7a4..1ac39737826b 100644 --- a/arch/x86/lib/insn-eval.c +++ b/arch/x86/lib/insn-eval.c @@ -1052,17 +1052,36 @@ out: return (void __user *)linear_addr; } -/* - * return the address being referenced be instruction - * for rm=3 returning the content of the rm reg - * for rm!=3 calculates the address using SIB and Disp +/** + * get_addr_ref_64() - Obtain a 64-bit linear address + * @insn: Instruction struct with ModRM and SIB bytes and displacement + * @regs: Structure with register values as seen when entering kernel mode + * + * This function is to be used with 64-bit address encodings to obtain the + * linear memory address referred by the instruction's ModRM, SIB, + * displacement bytes and segment base address, as applicable. + * + * Returns: + * + * Linear address referenced by instruction and registers on success. + * + * -1L on error. */ -void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs) +#ifndef CONFIG_X86_64 +static void __user *get_addr_ref_64(struct insn *insn, struct pt_regs *regs) +{ + return (void __user *)-1L; +} +#else +static void __user *get_addr_ref_64(struct insn *insn, struct pt_regs *regs) { unsigned long linear_addr = -1L, seg_base; int regoff, ret; long eff_addr; + if (insn->addr_bytes != 8) + goto out; + if (X86_MODRM_MOD(insn->modrm.value) == 3) { ret = get_eff_addr_reg(insn, regs, ®off, &eff_addr); if (ret) @@ -1090,3 +1109,34 @@ void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs) out: return (void __user *)linear_addr; } +#endif /* CONFIG_X86_64 */ + +/** + * insn_get_addr_ref() - Obtain the linear address referred by instruction + * @insn: Instruction structure containing ModRM byte and displacement + * @regs: Structure with register values as seen when entering kernel mode + * + * Obtain the linear address referred by the instruction's ModRM, SIB and + * displacement bytes, and segment base, as applicable. In protected mode, + * segment limits are enforced. + * + * Returns: + * + * Linear address referenced by instruction and registers on success. + * + * -1L on error. + */ +void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs) +{ + if (!insn || !regs) + return (void __user *)-1L; + + switch (insn->addr_bytes) { + case 4: + return get_addr_ref_32(insn, regs); + case 8: + return get_addr_ref_64(insn, regs); + default: + return (void __user *)-1L; + } +} |