[tboot-devel] txt-acminfo segfaults

[Timo L. <tim...@ik...>]

Hi,

txt-acminfo 5th_gen_i5_i7_SINIT_79.BIN

segfaults on my system:

Program received signal SIGSEGV, Segmentation fault.
does_acmod_match_platform (hdr=hdr@entry=0x7ffff7fc3000) at ../tboot/txt/acmod.c:590
590	    txt_heap_t *txt_heap = get_txt_heap();
(gdb) bt
#0  does_acmod_match_platform (hdr=hdr@entry=0x7ffff7fc3000) at ../tboot/txt/acmod.c:590
#1  0x00005555555552de in match_platform (hdr=0x7ffff7fc3000) at txt-acminfo.c:207
#2  main (argc=<optimized out>, argv=<optimized out>) at txt-acminfo.c:244
(gdb) x/4i $rip
=> 0x555555556612 <does_acmod_match_platform+50>:	movabs 0xfed30300,%rax
    0x55555555661c <does_acmod_match_platform+60>:	cmpb   $0x4,0x11(%rbp)
    0x555555556620 <does_acmod_match_platform+64>:	jbe    0x555555556660 <does_acmod_match_platform+128>
    0x555555556622 <does_acmod_match_platform+66>:	cmpl   $0x5,0x8(%rax)

It seems heap.h defines get_txt_heap() that refers to the real 
read_pub_config_reg() before it is #define'd later. After I fixed this I 
noticed that does_acmod_match_platform() then segfaults when it tries to 
dereference the pointer returned by get_txt_heap().

I guess txt-acminfo should mmap() TXT heap? Should we then modify 
get_txt_heap() to behave differently depending on the context or perhaps 
modify does_acmod_match_platform() to take a pointer to the TXT heap as an 
argument to avoid this?


-Timo