Why is my nasm program killing itself?
in [ASM]
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From: Frank Kotler on 5 Apr 2008 21:26 Chuck Crayne wrote: > On Sun, 06 Apr 2008 00:14:18 GMT > Frank Kotler <fbkotler(a)verizon.net> wrote: > > >>When/if I find "likely()" and or "unlikely()", I'll run the >>idea through 'em. :) > > > "likely" and "unlikely" are not functions, but branch prediction macros > to give hints to the compiler. From the standpoint of figuring out what > the code is trying to do, they can be (and should be) ignored. Ah. Okay. I expected macros to be uppercase. I was gonna joke that C had functions to decide whether to emit a "hint" or not. In that case, the names *do* make sense! And makes it "unlikely" I'm looking in the right place... No problem... there are others... Best, Frank
From: Herbert Kleebauer on 6 Apr 2008 05:31 Frank Kotler wrote: > Herbert Kleebauer wrote: > > NASM is the > > standard assembler for LINUX (for the assembly programmer, not for the > > C programmer). > > Nice of you to say so, but I'm not sure it's really true. I'm still > seein' (G)as code, not Nasm, in the kernel. AFAIK, most distros include > Nasm, these days. AFAIK, they *all* include (G)as. As Betov says, GAS is a C side assembler and therefore surely the standard assembler for people who do Linux C programming. But on the other side, GAS is very low level so I suppose that people who want to write pure assembly programs (if such people exist at all) will prefer NASM. > > And I can't believe that there are three kernel versions > > > > > Frank, I've tried that source on several machines and it gets killed > > > on both of them. These include kernel versions: > > > 2.6.23.9 > > > 2.6.21.5 > > > 2.6.12.4 > > > > which have this problem (and the OP uses exactly this three versions). > > Well... that's what he said... Presumably, intermediate numbers would be > affected, also(?). Just booted my Ubuntu and it is version 2.6.17.10. Tonight I will check the Linspire version (which is older). > > That's so unlikely, that it's even more > > probably that it is a virus which has problems to infect such small > > programs. > > That's an interesting theory. This virus can't infect our small > programs, so we get killed - apparently *before* gdb can load us. What's > it do to the ones it *can* infect? Does a virus scanner exist for Linux? > There are some programs that will run on Win9x, but not on XP. There are > some programs which will run on XP, but not on 9x. There are some > programs that will run on both. The latter category meet "extra > requirements". Unlikely as it may be, I *think* that's what we're up > against... But such trivial programs as discussed here will run on any Windows version (as long as it isn't 16 bit code in 64 bit Windows).
From: Phil Carmody on 6 Apr 2008 07:05 Frank Kotler <fbkotler(a)verizon.net> writes: > Chuck Crayne wrote: > > On Sun, 06 Apr 2008 00:14:18 GMT > > Frank Kotler <fbkotler(a)verizon.net> wrote: > > > >> When/if I find "likely()" and or "unlikely()", I'll run the idea > >> through 'em. :) > > "likely" and "unlikely" are not functions, but branch prediction > > macros > > to give hints to the compiler. From the standpoint of figuring out what > > the code is trying to do, they can be (and should be) ignored. > > Ah. Okay. I expected macros to be uppercase. I was gonna joke that C > had functions to decide whether to emit a "hint" or not. In that case, > the names *do* make sense! And makes it "unlikely" I'm looking in the > right place... No problem... there are others... They're linux specific. They substitute GCC-specific directives which are lower case and begin with 2 underscores. One of the reasons linux is so tied to GCC. Phil -- Dear aunt, let's set so double the killer delete select all. -- Microsoft voice recognition live demonstration
From: Frank Kotler on 9 Apr 2008 01:50 Herbert Kleebauer wrote: .... > Just booted my Ubuntu and it is version 2.6.17.10. Tonight I will > check the Linspire version (which is older). Well... I just installed Slackware 12.0 to "see for myself". Sure enough, "Killed". He wasn't bullshittin' us. The deal seems to be: if you've got a .bss section, you *must* also have a .data section. Just a .text section seems to be okay, unlike some earlier kernels. That's my enlightenment for the day. And it took *all* day! I started trying a "full" install on a partition that was just too small. Seemed to go alright, up until the end, when I couldn't install lilo. Retried without X and some other junk. Still wouldn't install lilo. "By force", I managed to get it to boot, and did a little testing. Okay, back to a saner (if "obsolete") kernel... Not so fast! Seems like *every* drive on my system (switched in bios setup) wants to boot that delightful new kernel now... and the "support" files aren't right! Fscking fsck first needs to check /dev/hda because it's been mounted 20 times without checking, next try, fsck has to check it because it hasn't been checked for 49710 days. Right. I think I'm going to be able to restore my system - I've gotten this far - but I wanted to post the "answer", in case I suicide first. .... > Does a virus scanner exist for Linux? Dunno, but I'd keep away from Slackware 12.0. Never had a problem with Slackware before... 13.0 will probably be fine. This one's not staying around long... if I can get rid of it! Best, Frank
From: Herbert Kleebauer on 9 Apr 2008 05:06
Frank Kotler wrote: > Well... I just installed Slackware 12.0 to "see for myself". Sure > enough, "Killed". He wasn't bullshittin' us. What was killed? Could you verify: Okaay, what is wrong with that: mov al, 10 This gets the program (another one) killed. If I change it into this: mov ax, 10 it is working! > The deal seems to be: if you've got a .bss section, you *must* also have > a .data section. Just a .text section seems to be okay, unlike some > earlier kernels. As far as I remember, elf doesn't know anything about .text or .bss. You just specify flags for the included segments. I use two segments, one for code and constants with the flags: SEGM00_flags=5 ; PF_R + PF_X (1: execute 2: write 4:read) and one for initialized and initialized data (.text + .bss) with the flags: SEGM01_flags=6 ; PF_R + PF_W (1: execute 2: write 4:read) > That's my enlightenment for the day. And it took *all* day! I started > trying a "full" install on a partition that was just too small. Seemed > to go alright, up until the end, when I couldn't install lilo. Retried > without X and some other junk. Still wouldn't install lilo. "By force", > I managed to get it to boot, and did a little testing. Okay, back to a > saner (if "obsolete") kernel... Not so fast! Seems like *every* drive on > my system (switched in bios setup) wants to boot that delightful new > kernel now... and the "support" files aren't right! Fscking fsck first > needs to check /dev/hda because it's been mounted 20 times without > checking, next try, fsck has to check it because it hasn't been checked > for 49710 days. Right. May be you should start to collect live CD's (which you can start directly from CD without installing on the disk) of the different Linux versions. > > Does a virus scanner exist for Linux? > > Dunno, but I'd keep away from Slackware 12.0. Never had a problem with > Slackware before... 13.0 will probably be fine. This one's not staying > around long... if I can get rid of it! Maybe Linux itself is a virus, go back to Windows! |