Re: [Crash-utility] [RFC] arm64: symbolize PLT entries in disassembling module functions

Signed-off-by: AKASHI Takahiro <takahiro.akashi(a)linaro.org&gt; --- arm64.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) diff --git a/arm64.c b/arm64.c index b9fa14d..8235e3c 100644 --- a/arm64.c +++ b/arm64.c @@ -2540,6 +2540,59 @@ arm64_is_task_addr(ulong task) return (IS_KVADDR(task) && (ALIGNED_STACK_OFFSET(task) == 0)); } +static ulong +PLT_veneer_to_kvaddr(ulong value) +{ + uint32_t insn; + ulong addr = 0; + int i; + + /* + * PLT veneer always looks: + * movn x16, #0x.... + * movk x16, #0x...., lsl #16 + * movk x16, #0x...., lsl #32 + * br x16 + */ + for (i = 0; i < 4; i++) { + if (!readmem(value + i * sizeof(insn), KVADDR, &insn, + sizeof(insn), "PLT veneer", RETURN_ON_ERROR)) { + error(WARNING, "cannot read PLT veneer\n"); + return value; + } + switch (i) { + case 0: + if ((insn & 0xffe0001f) != 0x92800010) + goto not_plt; + addr = ~((ulong)(insn & 0x1fffe0) >> 5); + break; + case 1: + if ((insn & 0xffe0001f) != 0xf2a00010) + goto not_plt; + addr &= 0xffffffff0000ffff; + addr |= (ulong)(insn & 0x1fffe0) << (16 - 5); + break; + case 2: + if ((insn & 0xffe0001f) != 0xf2c00010) + goto not_plt; + addr &= 0xffff0000ffffffff; + addr |= (ulong)(insn & 0x1fffe0) << (32 - 5); + break; + case 3: + if (insn != 0xd61f0200) + goto not_plt; + break; + default: + return value; /* to avoid any warnings */ + } + } + + return addr; + +not_plt: + return value; +} + /* * Filter dissassembly output if the output radix is not gdb's default 10 */ @@ -2589,6 +2642,22 @@ arm64_dis_filter(ulong vaddr, char *inbuf, unsigned int output_radix) sprintf(p1, "%s", buf1); } + if (IS_MODULE_VADDR(vaddr)) { + ulong orig_value; + + p1 = &inbuf[strlen(inbuf)-1]; + strcpy(buf1, inbuf); + argc = parse_line(buf1, argv); + + if ((STREQ(argv[argc-2], "b") || STREQ(argv[argc-2], "bl")) && + extract_hex(argv[argc-1], &orig_value, NULLCHAR, TRUE)) { + value = PLT_veneer_to_kvaddr(orig_value); + sprintf(p1, " <%s%s>\n", + value == orig_value ? "" : "plt:", + value_to_symstr(value, buf2, output_radix)); + } + } + console(" %s", inbuf); return TRUE; -- 2.10.0