Hi,
when debugging modules in linux kernel one must load symtab from each 
module using add-symbol-file command. However find_pc_sect_psymtab() 
returns with the first, usually less specific entry among all psymtabs 
instead of the newly added one, which leads to a situation where the 
wrong source file is chosen and therefore the "next", "next", ... 
stepping is unusable.

The attached patch modifies find_pc_sect_psymtab() so that it always 
returns the most specific symtab. Typical debugging session with 
verbosity tured on now looks like:
$ ./gdb /share/linux-2.4.21-2-mludvig/vmlinux
GNU gdb 2003-10-20-cvs
[...]
(gdb) add-symbol-file /share/lkm/lkm.o 0xffa00180c0
add symbol table from file "/share/lkm/lkm.o" at
         .text_addr = 0xffa00180c0
(y or n) y
Reading symbols from /share/lkm/lkm.o...done.
(gdb) set verbose
(gdb) l lkm_exit
More symtabs for PC=0xffffffffa00181b0 found:
         Ignoring vsyscall.c (vmlinux) PC=0xff802c9400...0xffff60042a
         Choosing lkm.c (lkm.o) PC=0xffa00180c0...0xffa00181d9
55      void
56      lkm_exit(void)
57      {
58        printk(KERN_INFO "Exitting LKM (jiffies=%lu)...\n", jiffies);
59        lkm_func(jiffies);
60      }
61
(gdb)

OK for mainline? Or should there be a different approach?

Michal Ludvig
-- 
sUsE cR, s.R.o             mludvig@suse.cz | I would like to change
(+420) 296.545.373      http://www.suse.cz | the world, but they wont
Personal homepage http://www.logix.cz/~mic | tell me the source code.