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author | 2011-08-19 16:15:10 -0700 | |
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committer | 2011-08-25 10:17:28 -0700 | |
commit | be27425dcc516fd08245b047ea57f83b8f6f0903 (patch) | |
tree | 0f7cfb258a663d99ebeedf8ed3b9637b266b021c /kernel | |
parent | firmware loader: allow builtin firmware load even if usermodehelper is disabled (diff) | |
download | linux-be27425dcc516fd08245b047ea57f83b8f6f0903.tar.gz linux-be27425dcc516fd08245b047ea57f83b8f6f0903.tar.bz2 linux-be27425dcc516fd08245b047ea57f83b8f6f0903.zip |
Add a personality to report 2.6.x version numbers
I ran into a couple of programs which broke with the new Linux 3.0
version. Some of those were binary only. I tried to use LD_PRELOAD to
work around it, but it was quite difficult and in one case impossible
because of a mix of 32bit and 64bit executables.
For example, all kind of management software from HP doesnt work, unless
we pretend to run a 2.6 kernel.
$ uname -a
Linux svivoipvnx001 3.0.0-08107-g97cd98f #1062 SMP Fri Aug 12 18:11:45 CEST 2011 i686 i686 i386 GNU/Linux
$ hpacucli ctrl all show
Error: No controllers detected.
$ rpm -qf /usr/sbin/hpacucli
hpacucli-8.75-12.0
Another notable case is that Python now reports "linux3" from
sys.platform(); which in turn can break things that were checking
sys.platform() == "linux2":
https://bugzilla.mozilla.org/show_bug.cgi?id=664564
It seems pretty clear to me though it's a bug in the apps that are using
'==' instead of .startswith(), but this allows us to unbreak broken
programs.
This patch adds a UNAME26 personality that makes the kernel report a
2.6.40+x version number instead. The x is the x in 3.x.
I know this is somewhat ugly, but I didn't find a better workaround, and
compatibility to existing programs is important.
Some programs also read /proc/sys/kernel/osrelease. This can be worked
around in user space with mount --bind (and a mount namespace)
To use:
wget ftp://ftp.kernel.org/pub/linux/kernel/people/ak/uname26/uname26.c
gcc -o uname26 uname26.c
./uname26 program
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/sys.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/kernel/sys.c b/kernel/sys.c index dd948a1fca4c..18ee1d2f6474 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -37,6 +37,8 @@ #include <linux/fs_struct.h> #include <linux/gfp.h> #include <linux/syscore_ops.h> +#include <linux/version.h> +#include <linux/ctype.h> #include <linux/compat.h> #include <linux/syscalls.h> @@ -44,6 +46,8 @@ #include <linux/user_namespace.h> #include <linux/kmsg_dump.h> +/* Move somewhere else to avoid recompiling? */ +#include <generated/utsrelease.h> #include <asm/uaccess.h> #include <asm/io.h> @@ -1161,6 +1165,34 @@ DECLARE_RWSEM(uts_sem); #define override_architecture(name) 0 #endif +/* + * Work around broken programs that cannot handle "Linux 3.0". + * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 + */ +static int override_release(char __user *release, int len) +{ + int ret = 0; + char buf[len]; + + if (current->personality & UNAME26) { + char *rest = UTS_RELEASE; + int ndots = 0; + unsigned v; + + while (*rest) { + if (*rest == '.' && ++ndots >= 3) + break; + if (!isdigit(*rest) && *rest != '.') + break; + rest++; + } + v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40; + snprintf(buf, len, "2.6.%u%s", v, rest); + ret = copy_to_user(release, buf, len); + } + return ret; +} + SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) { int errno = 0; @@ -1170,6 +1202,8 @@ SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) errno = -EFAULT; up_read(&uts_sem); + if (!errno && override_release(name->release, sizeof(name->release))) + errno = -EFAULT; if (!errno && override_architecture(name)) errno = -EFAULT; return errno; @@ -1191,6 +1225,8 @@ SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) error = -EFAULT; up_read(&uts_sem); + if (!error && override_release(name->release, sizeof(name->release))) + error = -EFAULT; if (!error && override_architecture(name)) error = -EFAULT; return error; @@ -1225,6 +1261,8 @@ SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) if (!error && override_architecture(name)) error = -EFAULT; + if (!error && override_release(name->release, sizeof(name->release))) + error = -EFAULT; return error ? -EFAULT : 0; } #endif |