linux-stable.git/include/linux/linkage.h, branch linux-2.6.25.y

Fix "$(AS) -traditional" compile breakage caused by asmlinkage_protect

2008-04-11T15:29:13+00:00

git commit 54a015104136974262afa4b8ddd943ea70dec8a2 ("asmlinkage_protect
replaces prevent_tail_call") causes this build failure on s390:

    AS      arch/s390/kernel/entry64.o
  In file included from arch/s390/kernel/entry64.S:14:
  include/linux/linkage.h:34: error: syntax error in macro parameter list
  make[1]: *** [arch/s390/kernel/entry64.o] Error 1
  make: *** [arch/s390/kernel] Error 2

and some other architectures.  The reason is that some architectures add
the "-traditional" flag to the invocation of $(AS), which disables
variadic macro argument support.

So just surround the new define with an #ifndef __ASSEMBLY__ to prevent
any side effects on asm code.

Cc: Roland McGrath 
Cc: Martin Schwidefsky 
Signed-off-by: Heiko Carstens 
Signed-off-by: Linus Torvalds

Add commentary about the new "asmlinkage_protect()" macro

2008-04-11T00:35:23+00:00

It's really a pretty ugly thing to need, and some day it will hopefully
be obviated by teaching gcc about the magic calling conventions for the
low-level system call code, but in the meantime we can at least add big
honking comments about why we need these insane and strange macros.

I took my comments from my version of the macro, but I ended up deciding
to just pick Roland's version of the actual code instead (with his
prettier syntax that uses vararg macros).  Thus the previous two commits
that actually implement it.

Signed-off-by: Linus Torvalds

asmlinkage_protect replaces prevent_tail_call

2008-04-11T00:28:26+00:00

The prevent_tail_call() macro works around the problem of the compiler
clobbering argument words on the stack, which for asmlinkage functions
is the caller's (user's) struct pt_regs.  The tail/sibling-call
optimization is not the only way that the compiler can decide to use
stack argument words as scratch space, which we have to prevent.
Other optimizations can do it too.

Until we have new compiler support to make "asmlinkage" binding on the
compiler's own use of the stack argument frame, we have work around all
the manifestations of this issue that crop up.

More cases seem to be prevented by also keeping the incoming argument
variables live at the end of the function.  This makes their original
stack slots attractive places to leave those variables, so the compiler
tends not clobber them for something else.  It's still no guarantee, but
it handles some observed cases that prevent_tail_call() did not.

Signed-off-by: Roland McGrath 
Signed-off-by: Linus Torvalds

Final removal of FASTCALL()/fastcall

2008-02-14T00:21:18+00:00

All users are gone, remove definitions and comments referring
to them.

Signed-off-by: Harvey Harrison 
Acked-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

x86: add ENDPROC() markers

2008-01-30T12:33:13+00:00

The ENDPROCs() were not used everywhere.  Some code used just END() instead,
while other code used nothing.  um/sys-i386/checksum.S didn't #include
 .  I also got confused because gcc puts the
.type near the ENTRY, while ENDPROC puts it on the opposite end.

Signed off by: John Reiser 
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner

x86: fix UML and -regparm=3

2008-01-30T12:33:00+00:00

introduce the "asmregparm" calling convention: for functions
implemented in assembly with a fixed regparm input parameters
calling convention.

mark the semaphore and rwsem slowpath functions with that.

Signed-off-by: Ingo Molnar 
Signed-off-by: Miklos Szeredi 
Signed-off-by: Thomas Gleixner

add WEAK() for creating weak asm labels

2007-10-22T15:13:17+00:00

Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: Rusty Russell 
Acked-by: H. Peter Anvin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] x86: error_code is not safe for kprobes

2006-09-26T08:52:34+00:00

This patch moves the entry.S:error_entry to .kprobes.text section,
since code marked unsafe for kprobes jumps directly to entry.S::error_entry,
that must be marked unsafe as well.
This patch also moves all the ".previous.text" asm directives to ".previous"
for kprobes section.

AK: Following a similar i386 patch from Chuck Ebbert
AK: Also merged Jeremy's fix in.

+From: Jeremy Fitzhardinge 

KPROBE_ENTRY does a .section .kprobes.text, and expects its users to
do a .previous at the end of the function.

Unfortunately, if any code within the function switches sections, for
example .fixup, then the .previous ends up putting all subsequent code
into .fixup.  Worse, any subsequent .fixup code gets intermingled with
the code its supposed to be fixing (which is also in .fixup).  It's
surprising this didn't cause more havok.

The fix is to use .pushsection/.popsection, so this stuff nests
properly.  A further cleanup would be to get rid of all
.section/.previous pairs, since they're inherently fragile.

+From: Chuck Ebbert <76306.1226@compuserve.com>

Because code marked unsafe for kprobes jumps directly to
entry.S::error_code, that must be marked unsafe as well.
The easiest way to do that is to move the page fault entry
point to just before error_code and let it inherit the same
section.

Also moved all the ".previous" asm directives for kprobes
sections to column 1 and removed ".text" from them.

Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andi Kleen

Don't include linux/config.h from anywhere else in include/

2006-04-26T11:56:16+00:00

Signed-off-by: David Woodhouse

[PATCH] abstract type/size specification for assembly

2006-03-24T15:33:25+00:00

Provide abstraction for generating type and size information of assembly
routines and data, while permitting architectures to override these
defaults.

Signed-off-by: Jan Beulich 
Cc: "Russell King" 
Cc: Ralf Baechle 
Cc: "Andi Kleen" 
Cc: "Luck, Tony" 
Cc: Miles Bader 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds