Question

I’m debugging a program (in Solaris) that may be writing into memory marked read-only, but I’m unsure how to determine whether that page of memory is actually marked as read-only.

Can I make that determination with gdb? If not, what can I use?

Answer 1

On Solaris you can look at the address space of a process by using the pmap command, e.g. pmap <pid>. This will display the r/w/x permissions for each mapping; along with other information.

Example from Solaris man page:

$ pmap 102905
102905:    sh
00010000    192K r-x--  /usr/bin/ksh
00040000      8K rwx--  /usr/bin/ksh
00042000     40K rwx--    [ heap ]
FF180000    664K r-x--  /usr/lib/libc.so.1
FF236000     24K rwx--  /usr/lib/libc.so.1
FF23C000      8K rwx--  /usr/lib/libc.so.1
FF250000      8K rwx--    [ anon ]
...
 total     1880K