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

[Dave Anderson]

Takahiro,

Nice!  Queued for crash-7.1.6:
 
  
https://github.com/crash-utility/crash/commit/f08a9c8bceadcbd15a21b5dc314aa84353a26547

Thanks,
  Dave

  
- Original Message -
> Signed-off-by: AKASHI Takahiro 
> ---
>  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, ,
> + 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 &= 0x;
> + addr |= (ulong)(insn & 0x1fffe0) << (16 - 5);
> + break;
> + case 2:
> + if ((insn & 0xffe0001f) != 0xf2c00010)
> + goto not_plt;
> + addr &= 0x;
> + 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 = [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], _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

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

[AKASHI Takahiro]

Signed-off-by: AKASHI Takahiro 
---
 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, ,
+   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 &= 0x;
+   addr |= (ulong)(insn & 0x1fffe0) << (16 - 5);
+   break;
+   case 2:
+   if ((insn & 0xffe0001f) != 0xf2c00010)
+   goto not_plt;
+   addr &= 0x;
+   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 = [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], _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

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