linux_dsm_epyc7002/arch/um
Jeff Dike 3963333fe6 uml: cover stubs with a VMA
Give the stubs a VMA.  This allows the removal of a truly nasty kludge to make
sure that mm->nr_ptes was correct in exit_mmap.  The underlying problem was
always that the stubs, which have ptes, and thus allocated a page table,
weren't covered by a VMA.

This patch fixes that by using install_special_mapping in arch_dup_mmap and
activate_context to create the VMA.  The stubs have to be moved, since
shift_arg_pages seems to assume that the stack is the only VMA present at that
point during exec, and uses vma_adjust to fiddle its VMA.  However, that
extends the stub VMA by the amount removed from the stack VMA.

To avoid this problem, the stubs were moved to a different fixed location at
the start of the address space.

The init_stub_pte calls were moved from init_new_context to arch_dup_mmap
because I was occasionally seeing arch_dup_mmap not being called, causing
exit_mmap to die.  Rather than figure out what was really happening, I decided
it was cleaner to just move the calls so that there's no doubt that both the
pte and VMA creation happen, no matter what.  arch_exit_mmap is used to clear
the stub ptes at exit time.

The STUB_* constants in as-layout.h no longer depend on UM_TASK_SIZE, that
that definition is removed, along with the comments complaining about gcc.

Because the stubs are no longer at the top of the address space, some care is
needed while flushing TLBs.  update_pte_range checks for addresses in the stub
range and skips them.  flush_thread now issues two unmaps, one for the range
before STUB_START and one for the range after STUB_END.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:29 -08:00
..
drivers uml: add missing space 2008-02-05 09:44:28 -08:00
include uml: cover stubs with a VMA 2008-02-05 09:44:29 -08:00
kernel uml: cover stubs with a VMA 2008-02-05 09:44:29 -08:00
os-Linux uml: kill processes instead of panicing kernel 2008-02-05 09:44:28 -08:00
scripts uml: throw out CONFIG_MODE_TT 2007-10-16 09:43:05 -07:00
sys-i386 uml: simplify SIGSEGV handling 2008-02-05 09:44:28 -08:00
sys-ia64 Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sys-ppc kbuild: enable 'make AFLAGS=...' to add additional options to AS 2007-10-15 21:59:31 +02:00
sys-x86_64 uml: kill processes instead of panicing kernel 2008-02-05 09:44:28 -08:00
defconfig uml: fix stub address calculations 2007-10-16 09:43:09 -07:00
Kconfig uml: SMP needs to depend on BROKEN for now 2008-02-05 09:44:25 -08:00
Kconfig.char uml: fix URLs in Kconfig and help strings 2008-02-05 09:44:25 -08:00
Kconfig.debug uml: GPROF needs to depend on FRAME_POINTER 2008-02-05 09:44:25 -08:00
Kconfig.i386 uml: keep UML Kconfig in sync with x86 2007-12-03 08:13:17 -08:00
Kconfig.net uml: fix URLs in Kconfig and help strings 2008-02-05 09:44:25 -08:00
Kconfig.x86_64 uml: fix stub address calculations 2007-10-16 09:43:09 -07:00
Makefile uml: allow LFLAGS on command line 2008-02-05 09:44:26 -08:00
Makefile-i386 no need to mess with KBUILD_CFLAGS on uml-i386 anymore 2007-12-05 09:25:20 -08:00
Makefile-ia64 Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile-os-Linux kbuild: enable 'make CFLAGS=...' to add additional options to CC 2007-10-14 22:21:35 +02:00
Makefile-ppc Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile-skas [PATCH] uml makefiles sanitized 2005-09-29 08:46:26 -07:00
Makefile-tt Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile-x86_64 x86 merge fallout: uml 2007-10-29 07:41:32 -07:00