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path: root/kernel/sysctl_binary.c
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2009-12-23SYSCTL: Print binary sysctl warnings (nearly) only onceAndi Kleen
When printing legacy sysctls print the warning message for each of them only once. This way there is a guarantee the syslog won't be flooded for any sane program. The original attempt at this made the tables non const and stored the flag inline. Linus suggested using a separate hash table for this, this is based on a code snippet from him. The hash implies this is not exact and can sometimes not print a new sysctl due to a hash collision, but in practice this should not be a problem I used a FNV32 hash over the binary string with a 32byte bitmap. This gives relatively little collisions when all the predefined binary sysctls are hashed: size 256 bucket length number 0: [25] 1: [67] 2: [88] 3: [47] 4: [22] 5: [6] 6: [1] The worst case is a single collision of 6 hash values. Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16[sysctl] Fix breakage on systems with older glibcAndi Kleen
As predicted during code review, the sysctl(2) changes made systems with old glibc nearly unusable. About every command gives a: warning: process `ls' used the deprecated sysctl system call with 1.4 warning in the log. I see this on a SUSE 10.0 system with glibc 2.3.5. Don't warn for this common case. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-11-12sysctl binary: Reorder the tests to process wild card entries first.Eric W. Biederman
A malicious user could have passed in a ctl_name of 0 and triggered the well know ctl_name to procname mapping code, instead of the wild card matching code. This is a slight problem as wild card entries don't have procnames, and because in some alternate universe a network device might have ifindex 0. So test for and handle wild card entries first. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-12sysctl: sysctl_binary.c Fix compilation when !CONFIG_NETEric W. Biederman
dev_get_by_index does not exist when the network stack is not compiled in, so only include the code to follow wild card paths when the network stack is present. I have shuffled the code around a little to make it clear that dev_put is called after dev_get_by_index showing that there is no leak. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-12sysctl: Warn about all uses of sys_sysctl.Eric W. Biederman
Now that the glibc pthread implemenation no longers uses sysctl() users of sysctl are as rare as hen's teeth. So remove the glibc exception from the warning, and use the standard printk_ratelimit instead of rolling our own. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-11sysctl: Reduce sys_sysctl to a compatibility wrapper around /proc/sysEric W. Biederman
To simply maintenance and to be able to remove all of the binary sysctl support from various subsystems I have rewritten the binary sysctl code as a compatibility wrapper around proc/sys. The code is built around a hard coded table based on the table in sysctl_check.c that lists all of our current binary sysctls and provides enough information to convert from the sysctl binary input into into ascii and back again. New in this patch is the realization that the only dynamic entries that need to be handled have ifname as the asscii string and ifindex as their ctl_name. When a sys_sysctl is called the code now looks in the translation table converting the binary name to the path under /proc where the value is to be found. Opens that file, and calls into a format conversion wrapper that calls fop->read and then fop->write as appropriate. Since in practice the practically no one uses or tests sys_sysctl rewritting the code to be beautiful is a little silly. The redeeming merit of this work is it allows us to rip out all of the binary sysctl syscall support from everywhere else in the tree. Allowing us to remove a lot of dead (after this patch) and barely maintained code. In addition it becomes much easier to optimize the sysctl implementation for being the backing store of /proc/sys, without having to worry about sys_sysctl. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-06sysctl: Make do_sysctl staticEric W. Biederman
Now that all of the architectures use compat_sys_sysctl do_sysctl can become static. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-06sysctl: Introduce a generic compat sysctl sysctlEric W. Biederman
This uses compat_alloc_userspace to remove the various hacks to allow do_sysctl to write to throuh oldlenp. The rest of our mature compat syscall helper facitilies are used as well to ensure we have a nice clean maintainable compat syscall that can be used on all architectures. The motiviation for a generic compat sysctl (besides the obvious hack removal) is to reduce the number of compat sysctl defintions out there so I can refactor the binary sysctl implementation. ppc already used the name compat_sys_sysctl so I remove the ppcs version here. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-06sysctl: Refactor the binary sysctl handling to remove duplicate codeEric W. Biederman
Read in the binary sysctl path once, instead of reread it from user space each time the code needs to access a path element. The deprecated sysctl warning is moved to do_sysctl so that the compat_sysctl entries syscalls will also warn. The return of -ENOSYS when !CONFIG_SYSCTL_SYSCALL is moved to binary_sysctl. Always leaving a do_sysctl available that handles !CONFIG_SYSCTL_SYSCALL and printing the deprecated sysctl warning allows for a single defitition of the sysctl syscall. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-06sysctl: Separate the binary sysctl logic into it's own file.Eric W. Biederman
In preparation for more invasive cleanups separate the core binary sysctl logic into it's own file. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>