Date: Mon, 30 Aug 2010 13:10:37 -0400 From: John Baldwin <jhb@freebsd.org> To: Alexander Fiveg <pebu3op@googlemail.com> Cc: freebsd-hackers@freebsd.org, doc@freebsd.org Subject: Re: Debugging Loadable Modules Using GDB Message-ID: <201008301310.38148.jhb@freebsd.org> In-Reply-To: <20100830161250.GA3135@debmaster-laptop> References: <20100827201140.GA2812@debmaster-laptop> <201008300816.11278.jhb@freebsd.org> <20100830161250.GA3135@debmaster-laptop>
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On Monday, August 30, 2010 12:12:50 pm Alexander Fiveg wrote: > On Mon, Aug 30, 2010 at 08:16:11AM -0400, John Baldwin wrote: > > On Friday, August 27, 2010 4:11:41 pm Alexander Fiveg wrote: > > > Hi, > > > from "FreeBSD Developers' Handbook, 10.7 Debugging Loadable Modules Using > > > GDB": > > > "... > > > (kgdb) add-symbol-file /sys/modules/linux/linux.ko 0xc0ae22d0 > > > ... > > > " > > > Actually I couldn't debug my modules using .ko-file. Moreover, I've find out > > that .ko files do not contain sections with debugging info. With .kld-file > > debugging works out. Do I something incorrectly or the info in the Developers > > Book is outdated? > > > > With newer versions of kgdb you shouldn't need to manually invoke 'add-symbol- > > file'. Kernel modules are treated as shared libraries and should > > automatically be loaded. Try using 'info sharedlibrary' to see the list of > > kernel modules and if symbols for them are loaded already. > Yes, the .ko files are loaded automatically. The problem is that they do > not contain debugging info. I have always to load the .kld file in order to > debug a module: > > (kgdb) f 9 > #9 0xc4dc558b in rm_8254_delayed_interrupt_per_packet () from > /boot/kernel/if_ringmap.ko > (kgdb) info locals > No symbol table info available. > > (kgdb) add-symbol-file /home/alexandre/p4/ringmap/current/sys/modules/ringmap/if_ringmap.kld 0xc4dafc70 > add symbol table from file "/home/alexandre/p4/ringmap/current/sys/modules/ringmap/if_ringmap.kld" > at > .text_addr = 0xc4dafc70 > (y or n) y > Reading symbols from /home/alexandre/p4/ringmap/current/sys/modules/ringmap/if_ringmap.kld...done. > > (kgdb) f 9 > #9 0xc4dc558b in rm_8254_delayed_interrupt_per_packet () > at /home/alexandre/p4/ringmap/current/sys/modules/ringmap/../../dev/e1000/ringmap_8254.c:142 > 142 co->ring->slot[slot_num].ts = co->ring->last_ts; > > (kgdb) info locals > co = (struct capt_object *) 0xc4d68380 > adapter = (struct adapter *) 0xc4e77000 > __func__ = "E\000\000�\034@\000\000\211\203�E\000\000\017\206B\022\000\000\2039\000\213A\004\017\205�\f\000\000\001��1�" > > > Is there any way to get the all symbols and needed debug info without > loading the .kld file ? How are you compiling the kld? If you are building it by hand, use 'make DEBUG_FLAGS=-g' when you build and install the kld. That should build with debug symbols enabled and install the ko.symbols file which kgdb will find and use. -- John Baldwin
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