Date: Fri, 28 Mar 1997 12:34:20 -0800 From: John Polstra <jdp@polstra.com> To: Shawn Carey <smc@servtech.com> Cc: dyson@freebsd.org, hackers@freebsd.org Subject: Re: Anyone else seen this? Message-ID: <199703282034.MAA04175@austin.polstra.com> In-Reply-To: Your message of "Fri, 28 Mar 1997 00:46:57 EST." <333B5B51.41C67EA6@servtech.com> References: <199703270427.XAA04344@dyson.iquest.net> <333AA089.41C67EA6@servtech.com> <199703280313.TAA28286@austin.polstra.com> <333B5B51.41C67EA6@servtech.com>
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> If I run the same executable under GDB, it runs for 10 seconds at the > most and then GDB kills it before reporting "Process terminated due to > text file modification". No breakpoints, no nuthin. Not even a > .gdbinit. > > Now, if I link with -static, the exectuable retains its timestamp, even > whe run under GDB, and GDB lets it run peacefully. It's worth noting that there are hooks between gdb and the dynamic linker. The dynamic linker can tell whether the program is being run under the debugger or not. If it is being run under the debugger, then the dynamic linker itself sets a breakpoint in the executable, to allow gdb to take control just after the shared libraries have all been loaded. So even if you don't explicitly set a breakpoint, one gets set anyway. > Any chance we have two unrelated but similar problems? Sure. > When I run my executable (linked against shared libs) directly from > the shell (GDB not involved), the timestamp on the file changes > every time, though it appears to run normally. I suppose it is possible that (due to an error in "ld" perhaps) your particular executable has the flag set that tells the dynamic linker the program is running under gdb. In that case, the dynamic linker would again set a breakpoint. Setting breakpoints shouldn't change the modtime of the file, of course, since it's mapped copy-on-write. So there still seems to be some sort of VM problem, regardless of these other considerations. John P. -- John Polstra jdp@polstra.com John D. Polstra & Co., Inc. Seattle, Washington USA "Self-knowledge is always bad news." -- John Barth
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