Commit Graph

268 Commits

Author SHA1 Message Date
Jeff Dike 2f56debd77 uml: fix FP register corruption
Commit ee3d9bd4de ("uml: simplify SIGSEGV
handling"), while greatly simplifying the kernel SIGSEGV handler that
runs in the process address space, introduced a bug which corrupts FP
state in the process.

Previously, the SIGSEGV handler called the sigreturn system call by hand - it
couldn't return through the restorer provided to it because that could try to
call the libc restorer which likely wouldn't exist in the process address
space.  So, it blocked off some signals, including SIGUSR1, on entry to the
SIGSEGV handler, queued a SIGUSR1 to itself, and invoked sigreturn.  The
SIGUSR1 was delivered, and was visible to the UML kernel after sigreturn
finished.

The commit eliminated the signal masking and the call to sigreturn.  The
handler simply hits itself with a SIGTRAP to let the UML kernel know that it
is finished.  UML then restores the process registers, which effectively
longjmps the process out of the signal handler, skipping sigreturn's restoring
of register state and the signal mask.

The bug is that the host apparently sets used_fp to 0 when it saves the
process FP state in the sigcontext on the process signal stack.  Thus, when
the process is longjmped out of the handler, its FP state is corrupt because
it wasn't saved on the context switch to the UML kernel.

This manifested itself as sleep hanging.  For some reason, sleep uses floating
point in order to calculate the sleep interval.  When a page fault corrupts
its FP state, it is faked into essentially sleeping forever.

This patch saves the FP state before entering the SIGSEGV handler and restores
it afterwards.

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>
2008-02-23 17:12:15 -08:00
Jeff Dike ac2a659968 uml: fix mm_context memory leak
[ Spotted by Miklos ]

Fix a memory leak in init_new_context.  The struct page ** buffer allocated
for install_special_mapping was never recorded, and thus leaked when the
mm_struct was freed.  Fix it by saving the pointer in mm_context_t and freeing
it in arch_exit_mmap.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:43 -08:00
Jeff Dike 5134d8fea0 uml: style fixes in arch/um/os-Linux
Style changes under arch/um/os-Linux:
	include trimming
	CodingStyle fixes
	some printks needed severity indicators

make_tempfile turns out not to be used outside of mem.c, so it is now static.
Its declaration in tempfile.h is no longer needed, and tempfile.h itself is no
longer needed.

create_tmp_file was also made static.

checkpatch moans about an EXPORT_SYMBOL in user_syms.c which is part of a
macro definition - this is copying a bit of kernel infrastructure into the
libc side of UML because the kernel headers can't be included there.

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>
2008-02-08 09:22:42 -08:00
Jeff Dike 536788fe2d uml: runtime host VMSPLIT detection
Calculate TASK_SIZE at run-time by figuring out the host's VMSPLIT - this is
needed on i386 if UML is to run on hosts with varying VMSPLITs without
recompilation.

TASK_SIZE is now defined in terms of a variable, task_size.  This gets rid of
an include of pgtable.h from processor.h, which can cause include loops.

On i386, task_size is calculated early in boot by probing the address space in
a binary search to figure out where the boundary between usable and non-usable
memory is.  This tries to make sure that a page that is considered to be in
userspace is, or can be made, read-write.  I'm concerned about a system-global
VDSO page in kernel memory being hit and considered to be a userspace page.

On x86_64, task_size is just the old value of CONFIG_TOP_ADDR.

A bunch of config variable are gone now.  CONFIG_TOP_ADDR is directly replaced
by TASK_SIZE.  NEST_LEVEL is gone since the relocation of the stubs makes it
irrelevant.  All the HOST_VMSPLIT stuff is gone.  All references to these in
arch/um/Makefile are also gone.

I noticed and fixed a missing extern in os.h when adding os_get_task_size.

Note: This has been revised to fix the 32-bit UML on 64-bit host bug that
Miklos ran into.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:42 -08:00
Jeff Dike f87ea91d98 uml: redo the calculation of NR_syscalls
Redo the calculation of NR_syscalls since that disappeared from i386 and
use a similar mechanism on x86_64.

We now figure out the size of the system call table in arch code and stick
that in syscall_table_size.  arch/um/kernel/skas/syscall.c defines
NR_syscalls in terms of that since its the only thing that needs to know
how many system calls there are.

The old mechananism that was used on x86_64 is gone.

arch/um/include/sysdep-i386/syscalls.h got some formatting since I was
looking at it.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:32 -08:00
Jeff Dike d449c50367 uml: remove unused fields from mm_context
The 3-level page table fixes forgot to remove a couple now-unused fields from
struct mm_context.

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 09:44:31 -08:00
Jeff Dike 95906b24fb uml: style fixes in arch/um/sys-x86_64
Style fixes in arch/um/sys-x86_64:
	updated copyrights
	CodingStyle fixes
	added severities to printks which needed them

A bunch of functions in sys-*/ptrace_user.c turn out to be unused, so they and
their declarations are gone.

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 09:44:31 -08:00
Jeff Dike 80e39311ff uml: SMP locking commentary
Add some more commentary about various pieces of global data not needing
locking.

Also got rid of unmap_physmem since that is no longer used.

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 09:44:30 -08:00
Jeff Dike 3a24ebf0cb uml: remove init_irq_signals
init_irq_signals doesn't need to be called from the context of a new process.
It initializes handlers, which are useless in process context.  With that call
gone, init_irq_signals has only one caller, so it can be inlined into
init_new_thread_signals.

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 09:44:30 -08:00
Jeff Dike 75ada8ffe0 uml: move sig_handler_common_skas
This patch moves sig_handler_common_skas from
arch/um/os-Linux/skas/trap.c to its only caller in
arch/um/os-Linux/signal.c.  trap.c is now empty, so it can be removed.

This is code movement only - the significant cleanup needed here is
done in the next patch.

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 09:44:30 -08:00
Jeff Dike a9b71b6c54 uml: get rid of syscall counters
Get rid of some syscall counters which haven't been useful in ages.

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 09:44:30 -08:00
Jeff Dike 1aa351a308 uml: tidy helper code
Style fixes to arch/um/os/helper.c and tidying up the breakpoint fix a
bit.

helper.c gets all the usual style fixes -
	 updated copyright
	 all printks get severities

Also -
	 errval changes to err in helper_child
	 fixed an obsolete comment
	 run_helper was killing a child process which is guaranteed to
be dead or dying anyway

Removed the nohang and pname arguments from helper_wait and fixed the
declaration and callers.  nohang was used only in the slirp driver and
I don't think it was needed.  I think pname was a bit of overkill in
putting out an error message when something goes wrong.

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 09:44:30 -08:00
Jeff Dike 0983a88b9f uml: install panic notifier earlier
It turns out that if there's a panic early enough, UML will just sit there in
the LED-blinking loop because the panic notifier hadn't been installed yet.

This patch installs it earlier.

It also fixes the problem which exposed the hang, namely that if you give UML
a zero-sized initrd, it will ask alloc_bootmem for zero bytes, and that will
cause the panic.

While I was in initrd.c, I gave it a style makeover.

Prompted by checkpatch, I moved a couple extern declarations of uml_exitcode
to kern_util.h.

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
Jeff Dike 8efa3c9d54 uml: eliminate setjmp_wrapper
setjmp_wrapper existed to provide setjmp to kernel code when UML used libc's
setjmp and longjmp.  Now that UML has its own implementation, this isn't
needed and kernel code can invoke setjmp directly.

do_buffer_op is massively cleaned up since it is no longer a callback from
setjmp_wrapper and given a va_list from which it must extract its arguments.

The actual setjmp is moved from buffer_op to do_op_one_page because the copy
operation is inside an atomic section (kmap_atomic to kunmap_atomic) and it
shouldn't be longjmp-ed out of.

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
Jeff Dike 1adfd6095e uml: style fixes in file.c
arch/um/os-Linux/file.c needed some style work -
	updated the copyright
	cleaned up the includes
	CodingStyle fixes
	added some missing CATCH_EINTRs
	os_set_owner was unused, so it is gone
	all printks now have severities
	fcntl(F_GETFL) was being called without checking the return
	removed an obsolete comment

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
Jeff Dike bf8fde785b uml: miscellaneous code cleanups
Code tidying -
	the pid field of struct irq_fd isn't used, so it is removed
     	os_set_fd_async needed to read flags before changing them, it
doesn't need a pid passed in because it can call getpid itself, and a
block of unused code needed deleting
	os_get_exec_close was unused, so it is removed
	ptrace_child called _exit for historical reasons which are no
longer valid, so just calls exit instead

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
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
Jeff Dike 42a2b54ce8 uml: clean up TASK_SIZE usage
Clean up the calculation and use of the usable address space size on the host.

task_size is gone, replaced with TASK_SIZE, which is calculated from
CONFIG_TOP_ADDR.  get_kmem_end and set_task_sizes_skas are also gone.

host_task_size, which refers to the entire address space usable by the UML
kernel and which may be larger than the address space usable by a UML process,
since that has to end on a pgdir boundary, is replaced by CONFIG_TOP_ADDR.

STACK_TOP is now TASK_SIZE minus the two stub pages.

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
Jeff Dike 3e6f2ac480 uml: kill processes instead of panicing kernel
UML was panicing in the case of failures of libc calls which shouldn't happen.
 This is an overreaction since a failure from libc doesn't normally mean that
kernel data structures are in an unknown state.  Instead, the current process
should just be killed if there is no way to recover.

The case that prompted this was a failure of PTRACE_SETREGS restoring the same
state that was read by PTRACE_GETREGS.  It appears that when a process tries
to load a bogus value into a segment register, it segfaults (as expected) and
the value is actually loaded and is seen by PTRACE_GETREGS (not expected).

This case is fixed by forcing a fatal SIGSEGV on the process so that it
immediately dies.  fatal_sigsegv was added for this purpose.  It was declared
as noreturn, so in order to pursuade gcc that it actually does not return, I
added a call to os_dump_core (and declared it noreturn) so that I get a core
file if somehow the process survives.

All other calls in arch/um/os-Linux/skas/process.c got the same treatment,
with failures causing the process to die instead of a kernel panic, with some
exceptions.

userspace_tramp exits with status 1 if anything goes wrong there.  That will
cause start_userspace to return an error.  copy_context_skas0 and
map_stub_pages also now return errors instead of panicing.  Callers of thes
functions were changed to check for errors and do something appropriate.
Usually that's to return an error to their callers.
check_skas3_ptrace_faultinfo just exits since that's too early to do anything
else.

save_registers, restore_registers, and init_registers now return status
instead of panicing on failure, with their callers doing something
appropriate.

There were also duplicate declarations of save_registers and restore_registers
in os.h - these are gone.

I noticed and fixed up some whitespace damage.

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 09:44:28 -08:00
Jeff Dike d25f2e1235 uml: use ptrace directly in libc code
Some register accessor cleanups -
	userspace() was calling restore_registers and save_registers for no
reason, since userspace() is on the libc side of the house, and these
add no value over calling ptrace directly
	init_thread_registers and get_safe_registers were the same thing,
so init_thread_registers is gone

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 09:44:28 -08:00
Jeff Dike 8192ab42bf uml: header untangling
Untangle UML headers somewhat and add some includes where they were
needed explicitly, but gotten accidentally via some other header.

arch/um/include/um_uaccess.h loses asm/fixmap.h because it uses no
fixmap stuff and gains elf.h, because it needs FIXADDR_USER_*, and
archsetjmp.h, because it needs jmp_buf.

pmd_alloc_one is uninlined because it needs mm_struct, and that's
inconvenient to provide in asm-um/pgtable-3level.h.

elf_core_copy_fpregs is also uninlined from elf-i386.h and
elf-x86_64.h, which duplicated the code anyway, to
arch/um/kernel/process.c, so that the reference to current_thread
doesn't pull sched.h or anything related into asm/elf.h.

arch/um/sys-i386/ldt.c, arch/um/kernel/tlb.c and
arch/um/kernel/skas/uaccess.c got sched.h because they dereference
task_structs.  Its includes of linux and asm headers got turned from
"" to <>.

arch/um/sys-i386/bug.c gets asm/errno.h because it needs errno
constants.

asm/elf-i386 gets asm/user.h because it needs user_regs_struct.

asm/fixmap.h gets page.h because it needs PAGE_SIZE and PAGE_MASK and
system.h for BUG_ON.

asm/pgtable doesn't need sched.h.

asm/processor-generic.h defined mm_segment_t, but didn't use it.  So,
that definition is moved to uaccess.h, which defines a bunch of
mm_segment_t-related stuff.  thread_info.h uses mm_segment_t, and
includes uaccess.h, which causes a recursion.  So, the definition is
placed above the include of thread_info. in uaccess.h.  thread_info.h
also gets page.h because it needs PAGE_SIZE.

ObCheckpatchViolationJustification - I'm not adding a typedef; I'm
moving mm_segment_t from one place to another.

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 09:44:28 -08:00
Karol Swietlicki 6b7e967484 uml: convert functions to void
This patch changes a few functions into returning void.  The return values
were not used anyway, so I think it should not be a problem.  Also removed a
little leftover bit from TT mode.

Signed-off-by: Karol Swietlicki <magotari@gmail.com>
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 09:44:26 -08:00
Jeff Dike edea138584 uml: tidy kern_util.h
Tidy kern_util.h.  It turns out that most of the function declarations
aren't used, so they can go away.  os.h no longer includes
kern_util.h, so files which got it through os.h now need to include it
directly.  A number of other files never needed it, so these includes
are deleted.

The structure which was used to pass signal handlers from the kernel
side to the userspace side is gone.  Instead, the handlers are
declared here, and used directly from libc code.  This allows
arch/um/os-Linux/trap.c to be deleted, with its remnants being moved
to arch/um/os-Linux/skas/trap.c.

arch/um/os-Linux/tty.c had its inclusions changed, and it needed some
style attention, so it got tidied.

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 09:44:26 -08:00
Jeff Dike e725a9b0f5 uml: delete some unused headers
Robert Day noticed a few unused headers in UML, so this gets rid of them.

Cc: "Robert P. J. Day" <rpjday@crashcourse.ca>
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 09:44:26 -08:00
Jeff Dike 4bdf8bc4a1 uml: borrow const.h techniques
Suggested by Geert Uytterhoeven - use const.h to get constants that are usable
in both C and assembly.  I can't include it directly since this code can't
include kernel headers.  const.h is also for numeric constants that can be
typed by tacking a "UL" or similar on the end.  The constants here have to be
typed by casting them.

So, the relevant parts of const.h are copied here and modified in order to
allow the constants to be uncasted in assembly and casted in C.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:26 -08:00
WANG Cong c0a9290ecf uml: const and other tidying
This patch also does some improvements for uml code.  Improvements include
dropping unnecessary cast, killing some unnecessary code and still some
constifying for pointers etc..

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
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 09:44:25 -08:00
Jeff Dike 9226b83847 uml: further bugs.c tidying
bugs.c, for both i386 and x86_64, can undergo further cleaning -
	The i386 arch_check_bugs only does one thing, so we might as
well inline the cmov checking.
	The i386 includes can be trimmed down a bit.
	arch_init_thread wasn't used, so it is deleted.
	The panics in arch_handle_signal are turned into printks
because the process is about to get segfaulted anyway, so something is
dying no matter what happens here.  Also, the return value was always
the same, so it contained no information, so it can be void instead.
The name is changed to arch_examine_signal because it doesn't handle
anything.
	The caller of arch_handle_signal, relay_signal, does things in
a different order.  The kernel-mode signal check is now first, which
puts everything else together, making things a bit clearer conceptually.

[akpm@linux-foundation.org: coding-style fixes]
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 09:44:25 -08:00
Karol Swietlicki 235a6f06eb uml: improve detection of host cmov
This patch introduces a new way of checking for the cmov instruction.  I use
signal handling instead of reading /proc/cpuinfo.

[ jdike - Fiddled the asm to make it obvious that it didn't mess with
any in-use registers and made test_for_host_cmov void ]

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Karol Swietlicki <magotari@gmail.com>
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 09:44:25 -08:00
Karol Swietlicki 0ba9d3f91d uml: fix URLs in Kconfig and help strings
This patch updates links which broke during the transition to the new UML
website.

Signed-off-by: Karol Swietlicki <magotari@gmail.com>
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 09:44:25 -08:00
WANG Cong c9a3072d13 uml: code tidying under arch/um/os-Linux
This patch contains varied fixes and improvements for some files under
arch/um/os-Linux/, such as a typo fix in a perror message, a missing
argument fix for a printf, some constifying for pointers and so on.

[ jdike - made sigprocmask failure return -errno instead of -1 ]

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
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 09:44:24 -08:00
Jeff Dike 99c9f502cb uml: arch/um/include/init.h needs a definition of __used
init.h started breaking now for some reason.  It turns out that there wasn't a
definition of __used.  Fixed this by copying the relevant stuff from
compiler.h in the userspace case, and including compiler.h in the kernel case.

[xiyou.wangcong@gmail.com: added definition of __section]
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:24 -08:00
Adrian Bunk 3ff6eecca4 remove __attribute_used__
Remove the deprecated __attribute_used__.

[Introduce __section in a few places to silence checkpatch /sam]

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-01-28 23:21:18 +01:00
Stanislaw Gruszka 4dbed85a35 uml: stop gdb from deleting breakpoints when running UML
Sometimes when UML is debugged gdb miss breakpoints.

When process traced by gdb do fork, debugger remove breakpoints from
child address space. There is possibility to trace more than one fork,
but this not work with UML, I guess (only guess) there is a deadlock -
gdb waits for UML and UML waits for gdb.

When clone() is called with SIGCHLD and CLONE_VM flags, gdb see this
as PTRACE_EVENT_FORK not as PTRACE_EVENT_CLONE and remove breakpoints
from child and at the same time from traced process, because either
have the same address space.

Maybe it is possible to do fix in gdb, but I'm not sure if there is
easy way to find out if traced and child processes share memory. So I
do fix for UML, it simply do not call clone() with both SIGCHLD and
CLONE_VM flags together.  Additionally __WALL flag is used for
waitpid() to assure not miss clone and normal process events.

[ jdike - checkpatch fixes ]

Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
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>
2007-12-17 19:28:15 -08:00
Jeff Dike 9c8d6381dc uml: fix build for !CONFIG_PRINTK
Handle the case of CONFIG_PRINTK being disabled.  This requires a do-nothing
stub to be present in arch/um/include/user.h so that we don't get references
to printk from libc code.

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>
2007-11-14 18:45:43 -08:00
Jeff Dike 54ae36f24b uml: fix stub address calculations
The calculation of CONFIG_STUB_CODE and CONFIG_STUB_DATA didn't take into
account anything but 3G/1G and 2G/2G, leaving the other vmsplits out in the
cold.

I'd rather not duplicate the four known host vmsplit cases for each of these
symbols.  I'd also like to calculate them based on the highest userspace
address.

The Kconfig language seems not to allow calculation of hex constants, so I
moved this to as-layout.h.  CONFIG_STUB_CODE, CONFIG_STUB_DATA, and
CONFIG_STUB_START are now gone.  In their place are STUB_CODE, STUB_DATA, and
STUB_START in as-layout.h.

i386 and x86_64 seem to differ as to whether an unadorned constant is an int
or a long, so I cast them to unsigned long so they can be printed
consistently.  However, they are also used in stub.S, where C types don't work
so well.  So, there are ASM_ versions of these constants for use in stub.S.  I
also ifdef-ed the non-asm-friendly portion of as-layout.h.

With this in place, most of the rest of this patch is changing CONFIG_STUB_*
to STUB_*, except in stub.S, where they are changed to ASM_STUB_*.

defconfig has the old symbols deleted.

I also print these addresses out in case there is any problem mapping them on
the host.

The two stub.S files had some trailing whitespace, so that is cleaned up here.

[akpm@linux-foundation.org: coding-style fixes]
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>
2007-10-16 09:43:09 -07:00
Jeff Dike b53f35a809 uml: network driver MTU cleanups
A bunch of MTU-related cleanups in the network code.

First, there is the addition of the notion of a maximally-sized packet, which
is the MTU plus headers.  This is used to size the skb that will receive a
packet.  This allows ether_adjust_skb to go away, as it was used to resize the
skb after it was allocated.

Since the skb passed into the low-level read routine is no longer resized, and
possibly reallocated, there, they (and the write routines) don't need to get
an sk_buff **.  They just need the sk_buff * now.  The callers of
ether_adjust_skb still need to do the skb_put, so that's now inlined.

The MAX_PACKET definitions in most of the drivers are gone.

The set_mtu methods were all the same and did nothing, so they can be
removed.

The ethertap driver had a typo which doubled the size of the packet rather
than adding two bytes to it.  It also wasn't defining its setup_size, causing
a zero-byte kmalloc and crash when the invalid pointer returned from kmalloc
was dereferenced.

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>
2007-10-16 09:43:08 -07:00
Jeff Dike 1a80521990 uml: use *SEC_PER_*SEC constants
There are various uses of powers of 1000, plus the odd BILLION constant in the
time code.  However, there are perfectly good definitions of *SEC_PER_*SEC in
linux/time.h which can be used instaed.

These are replaced directly in kernel code.  Userspace code imports those
constants as UM_*SEC_PER_*SEC and uses these.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:08 -07:00
Jeff Dike 5f734614fc uml: time build fix
Put back an implementation of timeval_to_ns in arch/um/os-Linux/time.c.
tglx pointed out in his review of tickless support that there was a
perfectly good implementation of it in linux/time.h.  The problem is that
this is userspace code which can't pull in kernel headers and there doesn't
seem to be a libc version.

So, I'm copying the version from linux/time.h rather than resurrecting my
version.  This causes some declaration changes as it now returns a signed
value rather than an unsigned value.

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>
2007-10-16 09:43:08 -07:00
Jeff Dike b160fb6309 uml: eliminate interrupts in the idle loop
Now, the idle loop now longer needs SIGALRM firing - it can just sleep for the
requisite amount of time and fake a timer interrupt when it finishes.

Any use of ITIMER_REAL now goes away.  disable_timer only turns off
ITIMER_VIRTUAL.  switch_timers is no longer needed, so it, and all calls, goes
away.

disable_timer now returns the amount of time remaining on the timer.
default_idle uses this to tell idle_sleep how long to sleep.  idle_sleep will
call alarm_handler if nanosleep returns 0, which is the case if it didn't
return early due to an interrupt.  Otherwise, it just returns.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:08 -07:00
Jeff Dike d2753a6d19 uml: tickless support
Enable tickless support.

CONFIG_TICK_ONESHOT and CONFIG_NO_HZ are enabled.

itimer_clockevent gets CLOCK_EVT_FEAT_ONESHOT and an implementation of
.set_next_event.

CONFIG_UML_REAL_TIME_CLOCK goes away because it only makes sense when there is
a clock ticking away all the time.  timer_handler now just calls do_IRQ once
without trying to figure out how many ticks to emulate.

The idle loop now needs to turn ticking on and off.

Userspace ticks keep happening as usual.  However, the userspace loop keep
track of when the next wakeup should happen and suppresses process ticks until
that happens.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:08 -07:00
Jeff Dike 78a26e25ce uml: separate timer initialization
Move timer signal initialization from init_irq_signals to a new function,
timer_init.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:08 -07:00
Jeff Dike a2f018bf38 uml: simplify interval setting
set_interval took a timer type as an argument, but it always specified a
virtual timer.  So, it is not needed, and it is gone, and set_interval is
simplified appropriately.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:08 -07:00
Jeff Dike 181bde801a uml: fix timer switching
Fix up the switching between virtual and real timers.  The idle loop sleeps,
so the timer at that point must be real time.  At all other times, the timer
must be virtual.  Even when userspace is running, and the kernel is asleep,
the virtual timer is correct because the process timer will be running and the
process timer will be firing.

The timer switch used to be in the context switch and timer handler code.
This is moved to the idle loop and the signal handler, making it much more
clear why it is happening.

switch_timers now returns the old timer type so that it may be restored.  The
signal handler uses this in order to restore the previous timer type when it
returns.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:08 -07:00
Jeff Dike 532d0fa4d1 uml: eliminate hz()
Eliminate hz() since its only purpose was to provide a kernel-space constant
to userspace code.  This can be done instead by providing the constant
directly through kernel_constants.h.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:08 -07:00
Jeff Dike 75c7e214ba uml: eliminate floating point state from register file
The floating point fields in the pt_regs register file aren't used, so they
are deleted.

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>
2007-10-16 09:43:07 -07:00
Jeff Dike f0c4cad99c uml: style fixes in FP code
Tidy the code affected by the floating point fixes.

A bunch of unused stuff is gone, including two sigcontext.c files,
which turned out to be entirely unneeded.

There are the usual fixes -
	whitespace and style cleanups
	copyright updates
	emacs formatting comments gone
	include cleanups
	adding severities to printks

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>
2007-10-16 09:43:07 -07:00
Jeff Dike a5f6096c80 uml: floating point signal delivery fixes
Handle floating point state in across signals correctly.  UML/i386 needs to
know whether the host does PTRACE_[GS]ETFPXREGS, so an arch_init_registers
hook is added, which on x86_64 does nothing.

UML doesn't save and restore floating point registers on kernel entry and
exit, so they need to be copied between the host process and the sigcontext.
save_fpx_registers and restore_fpx_registers are added for this purpose.
save_fp_registers and restore_fp_registers already exist.

There was a bunch of floating point state conversion code in
arch/um/sys-i386/ptrace.c which isn't needed there, but is needed in signal.c,
so it is moved over.

The i386 code now distinguishes between fp and fpx state and handles them
correctly.  The x86_64 code just needs to copy state as-is between the host
process and the stack.  There are also some fixes there to pass the correct
address of the floating point state around.

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>
2007-10-16 09:43:07 -07:00
Jeff Dike 1466abf2d0 uml: clean up tlb flush path
Tidy the tlb flushing code.

With tt mode gone, there is no reason to have the capability to have
called directly from do_mmap, do_mprotect, and do_munmap, rather than
calling a function pointer that it is given.

There was a large amount of data that was passed from function to
function, being used at the lowest level, without being changed.  This
stuff is now encapsulated in a structure which is initialized at the
top layer and passed down.  This simplifies the code, reduces the
amount of code needed to pass the parameters around, and saves on
stack space.

A somewhat more subtle change is the meaning of the current operation
index.  It used to start at -1, being pre-incremented when adding an
operation.  It now starts at 0, being post-incremented, with
associated adjustments of +/- 1 on comparisons.

In addition, tlb.h contained a couple of declarations which had no
users outside of tlb.c, so they could be moved or deleted.

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>
2007-10-16 09:43:06 -07:00
Jeff Dike 512b6fb1c1 uml: userspace files should call libc directly
A number of files that were changed in the recent removal of tt mode
are userspace files which call the os_* wrappers instead of calling
libc directly.  A few other files were affected by this, through

This patch makes these call glibc directly.

There are also style fixes in the affected areas.

os_print_error has no remaining callers, so it is deleted.

There is a interface change to os_set_exec_close, eliminating a
parameter which was always the same.  The callers are fixed as well.

os_process_pc got its error path cleaned up.

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>
2007-10-16 09:43:06 -07:00
Jeff Dike 8ca842c4b5 uml: remove os_* usage from userspace files
This patch fixes some userspace files which were calling libc through the os_*
wrappers.

It turns out that there was only one user of os_new_tty_pgrp, so it can be
deleted.

There are also some style and whitespace fixes in here.

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>
2007-10-16 09:43:06 -07:00