Commit Graph

4 Commits

Author SHA1 Message Date
Olaf Faaland cd2209b75e glibc 2.5 compat: use correct header for makedev() et al.
In glibc 2.5, makedev(), major(), and minor() are defined in
sys/sysmacros.h.  They are also defined in types.h for backward
compatability, but using these definitions triggers a compile warning.
This breaks the ZFS build, as it builds with -Werror.

autoconf email threads indicate these macros may be defined in
sys/mkdev.h in some cases.

This commit adds configure checks to detect where makedev() is defined:
  sys/sysmacros.h
  sys/mkdev.h

It assumes major() and minor() are defined in the same place.

The libspl types.h then includes
	sys/sysmacros.h (preferred) or
	sys/mkdev.h (2nd choice)
if one of those defines makedev().

This is done before including the system types.h.

An alternative would be to remove uses of major, minor, and makedev,
instead comparing the st_dev returned from stat64.  These configure
checks would then be unnecessary.

This change revealed that __NORETURN was being defined unnecessarily in
libspl/include/sys/sysmacros.h.  That definition is removed.

The files in which __NORETURN are used all include types.h, and so all
will get the definition provided by feature_tests.h

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes #5945
2017-07-06 15:25:39 -07:00
Jason Zaman 44f547af98 sysmacros: Make P2ROUNDUP not trigger int overflow
The original P2ROUNDUP and P2ROUNDUP_TYPED macros contain -x which
triggers PaX's integer overflow detection for unsigned integers.
Replace the macros with an equivalent version that does not trigger
the overflow.

Axioms:
A. (-(x)) === (~((x) - 1)) === (~(x) + 1) under two's complement.
B. ~(x & y) === ((~(x)) | (~(y))) under De Morgan's law.
C. ~(~x) === x under the law of excluded middle.

Proof:
0. (-(-(x) & -(align))) original
1. (~(-(x) & -(align)) + 1) by A
2. (((~(-(x))) | (~(-(align)))) + 1) by B
3. (((~(~((x) - 1))) | (~(~((align) - 1)))) + 1) by A
4. (((((x) - 1)) | (((align) - 1))) + 1) by C
Q.E.D.

Signed-off-by: Jason Zaman <jason@perfinion.com>
Reviewed-by: Chris Dunlop <chris@onthe.net.au>
Reviewed-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3949
2015-12-23 17:29:35 -08:00
Michael Kjorling d1d7e2689d cstyle: Resolve C style issues
The vast majority of these changes are in Linux specific code.
They are the result of not having an automated style checker to
validate the code when it was originally written.  Others were
caused when the common code was slightly adjusted for Linux.

This patch contains no functional changes.  It only refreshes
the code to conform to style guide.

Everyone submitting patches for inclusion upstream should now
run 'make checkstyle' and resolve any warning prior to opening
a pull request.  The automated builders have been updated to
fail a build if when 'make checkstyle' detects an issue.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1821
2013-12-18 16:46:35 -08:00
Brian Behlendorf a26baf285f Add linux libspl support
All changes needed for the libspl layer.  This includes modifications
to files directly copied from OpenSolaris and the addition of new
files needed to fill in the gaps.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-08-31 13:41:59 -07:00