Date: Tue, 06 May 2008 07:55:03 -0400 From: Martes G Wigglesworth <martes@mgwigglesworth.com> To: Alexander Sack <pisymbol@gmail.com> Cc: Kostik Belousov <kostikbel@gmail.com>, "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>, David Christensen <davidch@broadcom.com> Subject: Re: Not All Symbols Present in a Loadable Kernel Module Message-ID: <1210074903.8179.9.camel@localhost> In-Reply-To: <3c0b01820805051106k5faf368etec0851e65de109f8@mail.gmail.com> References: <5D267A3F22FD854F8F48B3D2B523819324F09D65FA@IRVEXCHCCR01.corp.ad.broadcom.com> <3c0b01820805021315i482fe0acg3e9238a2f412770e@mail.gmail.com> <5D267A3F22FD854F8F48B3D2B523819324F09D6896@IRVEXCHCCR01.corp.ad.broadcom.com> <3c0b01820805030750k2fc389b0y500914c36069e6cf@mail.gmail.com> <5D267A3F22FD854F8F48B3D2B523819324F09D6A52@IRVEXCHCCR01.corp.ad.broadcom.com> <20080505163249.GU18958@deviant.kiev.zoral.com.ua> <3c0b01820805051106k5faf368etec0851e65de109f8@mail.gmail.com>
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I thought that the "inline" switch was specific to C++ and C and not gcc, hence the standard for the language says to add the inline parameter to explicitly produce optimized code. Unless gcc is not standard, I don't see why the compiler would automatically optimize the coded function to "inline." On Mon, 2008-05-05 at 14:06 -0400, Alexander Sack wrote: > For my own edification, unless you specifically mark a function > inline, will gcc really optimize them out? That seems a little > overboard unless there is some compiler option that says its okay to > do that. I guess that would be very easy to test if you do as you > say, just sock away the function address pointer somewhere and you > should be okay... > > -aps > > On Mon, May 5, 2008 at 12:32 PM, Kostik Belousov <kostikbel@gmail.com> wrote: > > > > On Mon, May 05, 2008 at 09:27:10AM -0700, David Christensen wrote: > > > > > Yes, I'm building a debug kernel. I have the line listed above as > > > > well > > > > > as the following: > > > > > > > > > > options KDB > > > > > options DDB > > > > > options GDB > > > > > options INVARIANTS > > > > > options INVARIANT_SUPPORT > > > > > options WITNESS > > > > > options WITNESS_SKIPSPIN > > > > > > > > Dave: > > > > > > > > What symbols can you not access exactly and how are you > > > > installing/setting up debugging? > > > > > > > > I just built a RELENG_7 with DDB and I'm able to access bce symbols > > > > without a problem. I can examine them and call them. I'm not using > > > > options GDB however, only KDB/DDB. > > > > > > > > I would: > > > > > > > > - Make sure you have the right if_bce.ko/if_bce.ko.symbols files > > > > generated/installed which contains the debug sections of your ko (from > > > > the objcopy calls during the build - the binary is stripped with a > > > > section pointer to the if_bce.ko.symbols file for debugging > > > > information I believe) > > > > - If you are using GDB, make sure its pointed to the right source base > > > > so it can retrieve symbol information correctly > > > > - If you are using GDB, stub it out and just use DDB to verify that > > > > your build is sane (it works for me!) > > > > - If all else fails, you can always build bce statically (just to move > > > > forward etc.) > > > > > > - Enable the kernel debugger as described above > > > - Build the driver in the /usr/src/sys/modules/bce directory with the > > > command "make". > > > - Run the command "nm if_bce.ko | grep dump_stat" in the same directory > > > with the kernel module just built. > > > > > > In my case I only see a symbol for bce_dump_status_block, but there is a > > > second routine called bce_dump_stats_block. In my working build there > > > are 23 functions that start with "bce_dump" but only 8 are displayed with > > > the command "nm if_bce.ko | grep bce_dump". Of course, I also get the > > > symbol not present error when I try to use any of those missing symbols > > > through a "call" command in the debugger. > > > > Most likely, they are optimized out, gcc likes to inline once-called > > static functions. Aside from playing with the optimization options, > > the easiest way seems to use functions somewhere else, e.g., put the > > addresses into some table. Just guessing. > > > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" >
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