Alfred Peng wrote:
> The option "-M /usr/lib/ld/map.noexstk" has been added to the build
> configuration, and the content of the file map.noexstk is "stack = STACK
> ?RW;". I just wonder whether there is a way for me to test the function
> after building successfully?
This mapfile creates a program header that tells the kernel that
the process requires a non-executable stack. You can see this from
the read/write access, but no execute access, assigned to the
program header:
% cc -o main main.c -M/usr/lib/ld/map.noexstk
% elfdump -p main | tail -6
Program Header[5]:
p_vaddr: 0 p_flags: [ PF_W PF_R ]
p_paddr: 0 p_type: [ PT_SUNWSTACK ]
p_filesz: 0 p_memsz: 0
p_offset: 0 p_align: 0
You can use ptools on the application to verify the stacks
accessibility:
% truss -Texit ./main
.......
% pmap -x 184337
184337: ./main
Address Kbytes RSS Anon Locked Mode Mapped File
00010000 8 8 - - r-x-- main
00020000 8 8 8 - rwx-- main
........
FFBFE000 8 8 8 - rw--- [ stack ]
--
Rod
