linux.git/arch/um, branch v2.6.18

[PATCH] vDSO hash-style fix

2006-07-31T20:28:43+00:00

The latest toolchains can produce a new ELF section in DSOs and
dynamically-linked executables.  The new section ".gnu.hash" replaces
".hash", and allows for more efficient runtime symbol lookups by the
dynamic linker.  The new ld option --hash-style={sysv|gnu|both} controls
whether to produce the old ".hash", the new ".gnu.hash", or both.  In some
new systems such as Fedora Core 6, gcc by default passes --hash-style=gnu
to the linker, so that a standard invocation of "gcc -shared" results in
producing a DSO with only ".gnu.hash".  The new ".gnu.hash" sections need
to be dealt with the same way as ".hash" sections in all respects; only the
dynamic linker cares about their contents.  To work with older dynamic
linkers (i.e.  preexisting releases of glibc), a binary must have the old
".hash" section.  The --hash-style=both option produces binaries that a new
dynamic linker can use more efficiently, but an old dynamic linker can
still handle.

The new section runs afoul of the custom linker scripts used to build vDSO
images for the kernel.  On ia64, the failure mode for this is a boot-time
panic because the vDSO's PT_IA_64_UNWIND segment winds up ill-formed.

This patch addresses the problem in two ways.

First, it mentions ".gnu.hash" in all the linker scripts alongside ".hash".
 This produces correct vDSO images with --hash-style=sysv (or old tools),
with --hash-style=gnu, or with --hash-style=both.

Second, it passes the --hash-style=sysv option when building the vDSO
images, so that ".gnu.hash" is not actually produced.  This is the most
conservative choice for compatibility with any old userland.  There is some
concern that some ancient glibc builds (though not any known old production
system) might choke on --hash-style=both binaries.  The optimizations
provided by the new style of hash section do not really matter for a DSO
with a tiny number of symbols, as the vDSO has.  If someone wants to use
=gnu or =both for their vDSO builds and worry less about that
compatibility, just change the option and the linker script changes will
make any choice work fine.

Signed-off-by: Roland McGrath 
Cc: "Luck, Tony" 
Cc: Kyle McMartin 
Cc: Paul Mackerras 
Cc: Benjamin Herrenschmidt 
Cc: Jeff Dike 
Cc: Andi Kleen 
Cc: Sam Ravnborg 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] UML - fix utsname build breakage

2006-07-15T21:42:24+00:00

Some -mm-only material leaked into a patch destined for mainline, and I didn't
notice.

This was the replacement of system_utsname with utsname() that's required by
the uts namespace patch.  This patch reverts those changes (which are correct
in -mm) so that mainline UML builds again.

Signed-off-by: Jeff Dike 
Signed-off-by: Linus Torvalds

[PATCH] uml: header formatting cleanups

2006-07-15T04:53:52+00:00

Clean up whitespace and return syntax in os.h.

Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] uml: tidy biarch gcc support

2006-07-15T04:53:52+00:00

On top of the previous biarch changes for UML, this makes the preprocessor
changes a bit cleaner.  Specify the 64-bit build in CPPFLAGS on the x86_64
SUBARCH, rather than #undef'ing i386.  Compile-tested with i386 and x86_64
SUBARCHs.

Signed-off-by: Nishanth Aravamudan 
Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] uml: tidy longjmp macro

2006-07-15T04:53:52+00:00

The UML_SETJMP macro was requiring its users to pass in a argument which it
could supply itself, since it wasn't used outside that invocation of the
macro.

Signed-off-by: Jeff Dike 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] uml: make mconsole version requests happen in a process

2006-07-10T20:24:24+00:00

Handling a host mconsole version request must be done in a process context
rather than interrupt context now that utsname information can be
process-specific rather than global.

Signed-off-by: Jeff Dike 
Cc: Paolo 'Blaisorblade' Giarrusso 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] uml: remove unused variable

2006-07-10T20:24:24+00:00

The dedevfsification of UML left an unused variable behind.

Signed-off-by: Jeff Dike 
Cc: Paolo 'Blaisorblade' Giarrusso 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] uml: add some EINTR protection

2006-07-10T20:24:24+00:00

Add some more uses of the CATCH_EINTR wrapper.

Signed-off-by: Jeff Dike 
Cc: Paolo 'Blaisorblade' Giarrusso 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] uml: formatting fixes

2006-07-10T20:24:24+00:00

Fix a bunch of formatting problems.

Signed-off-by: Jeff Dike 
Cc: Paolo 'Blaisorblade' Giarrusso 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] uml: move _kern.c files

2006-07-10T20:24:24+00:00

Move most *_kern.c files in arch/um/kernel to *.c.  This makes UML somewhat
more closely resemble the other arches.

[akpm@osdl.org: use the new INTF_* flags]
Signed-off-by: Jeff Dike 
Cc: Paolo 'Blaisorblade' Giarrusso 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds