On Fri, 2008-01-04 at 09:07 +0900, Tejun Heo wrote: > Hello, > > Andrew Patterson wrote: > > It looks like this is a shell issue. After looking through the sysfs > > code, I realized that this problem seems to be driven from user-land. > > So I performed some experiments: > > > > 1. Wrote a simple program that just used write(2) to write to the > > sysfs entry. This works fine. > > 2. Used /bin/echo instead of the built-in echo command. This too > > works fine. > > 3. Tried several shells. Zsh and Bash both fail. Csh works fine. > > > > I then ran strace on the following shell-script: > > > > #!/bin/bash > > > > echo x > allow_restart > > echo y > allow_restart > > echo z > allow_restart > > > > and got: > > > > # strace -e trace=write ~/tmp/tester.sh > > write(1, "x\n", 2) = -1 EINVAL (Invalid argument) > > write(1, "x\n", 2) = -1 EINVAL (Invalid argument) > > write(2, "/home/andrew/tmp/tester.sh: line"..., > > 72/home/andrew/tmp/tester.sh: line 4: echo: write error: Invalid argument > > ) = 72 > > write(1, "x\ny\n", 4) = -1 EINVAL (Invalid argument) > > write(1, "x\ny\n", 4) = -1 EINVAL (Invalid argument) > > write(2, "/home/andrew/tmp/tester.sh: line"..., > > 72/home/andrew/tmp/tester.sh: line 5: echo: write error: Invalid argument > > ) = 72 > > write(1, "x\ny\nz\n", 6) = -1 EINVAL (Invalid argument) > > write(1, "x\ny\nz\n", 6) = -1 EINVAL (Invalid argument) > > write(2, "/home/andrew/tmp/tester.sh: line"..., > > 72/home/andrew/tmp/tester.sh: line 6: echo: write error: Invalid argument > > ) = 72 > > write(1, "x\ny\nz\n", 6x > > y > > z > > ) = 6 > > Process 3800 detached > > Eeeeeeeekkkk.... That's scary. Which distro are you using and what does > 'bash --version' say?
IA64 Debian lenny. # bash --version GNU bash, version 3.1.17(1)-release (ia64-unknown-linux-gnu) # zsh --version zsh 4.3.4 (ia64-unknown-linux-gnu) # csh --version tcsh 6.14.00 (Astron) 2005-03-25 (ia64-unknown-linux) options wide,nls,dl,al,kan,rh,nd,color,filec I suppose I should try this an ia32 box again, and perhaps with some other distros. I am not sure what the kernel can do about this, but it might be nice to report it to the shell maintainers. -- Andrew Patterson Hewlett-Packard Company -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/