The PTE returned from handle_mm_fault is already marked as dirty and accessed
if needed.
Also, since this is not set with set_pte() (which sets NEWPAGE and NEWPROT as
needed), this wouldn't work anyway.
This version has been updated and fixed, thanks to some feedback from Jeff Dike.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The UML fault handler was recently changed to enforce PROT_NONE protections,
by requiring VM_READ or VM_EXEC on VMA's.
However, by mistake, things were changed such that VM_READ is always checked,
also on write faults; so a VMA mapped with only PROT_WRITE is not readable
(unless it's prefaulted with MAP_POPULATE or with a write), which is different
from i386.
Discovered while testing remap_file_pages protection support.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Turns out that, for UML, a *lot* of VM-related trivial functions are not
inlined but rather normal functions.
In other sections of UML code, this is justified by having files which
interact with the host and cannot therefore include kernel headers, but in
this case there's no such justification.
I've had to turn many of them to macros because of missing declarations. While
doing this, I've decided to reuse some already existing macros.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Inside the linker script, insert the code for DWARF debug info sections. This
may help GDB'ing a Uml binary. Actually, it seems that ld is able to guess
what I added correctly, but normal linker scripts include this section so it
should be correct anyway adding it.
On request by Sam Ravnborg <sam@ravnborg.org>, I've added it to
asm-generic/vmlinux.lds.s. I've also moved there the stabs debug section,
used the new macro in i386 linker script and added DWARF debug section to
that.
In the truth, I've not been able to verify the difference in GDB behaviour
after this change (I've seen large improvements with another patch). This
may depend on my binutils version, older one may have worse defaults.
However, this section is present in normal linker script, so add it at
least for the sake of cleanness.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
um has it own set of files for asm-offsets. So for now the
gen-asm-offset macro is just duplicated in the um Makefile.
This may well be the final solution since um is a bit special compared
to other architectures - time will tell.
Also added a dummy arch/um/kernel/asm-offsets.h file to keep kbuild happy.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
We were leaking pmd pages when 3_LEVEL_PGTABLES was enabled. This fixes that.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Change syscall-stub's data to include a "expected retval".
Stub now checks syscalls retval and aborts execution of syscall list, if
retval != expected retval.
run_syscall_stub prints the data of the failed syscall, using the data pointer
and retval written by the stub to the beginning of the stack.
one_syscall_stub is removed, to simplify code, because only some instructions
are saved by one_syscall_stub, no host-syscall.
Using the stub with additional data (modify_ldt via stub)
is prepared also.
Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This change enables SKAS0/SKAS3 to work with all combinations of /proc/mm and
PTRACE_FAULTINFO being available or not.
Also it changes the initialization of proc_mm and ptrace_faultinfo slightly,
to ease forcing SKAS0 on a patched host. Forcing UML to run without /proc/mm
or PTRACE_FAULTINFO by cmdline parameter can be implemented with a setup
resetting the related variable.
Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The serial UML OS-abstraction layer patch (um/kernel dir).
This moves all systemcalls from process.c file under os-Linux dir and join
process.c and process_kern.c files.
Signed-off-by: Gennady Sharapov <gennady.v.sharapov@intel.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch makes UML use host AIO support when it (and
/usr/include/linux/aio_abi.h) are present. This is only the support, with no
consumers - a consumer is coming in the next patch.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This merges two sets of files which had no business being split apart in the
first place.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds VM op batching to skas0. Rather than having a context switch to and
from the userspace stub for each address space change, we write a number of
operations to the stub data page and invoke a different stub which loops over
them and executes them all in one go.
The operations are stored as [ system call number, arg1, arg2, ... ] tuples.
The set is terminated by a system call number of 0. Single operations, i.e.
page faults, are handled in the old way, since that is slightly more
efficient.
For a kernel build, a minority (~1/4) of the operations are part of a set.
These sets averaged ~100 in length, so for this quarter, the context switching
overhead is greatly reduced.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Avoid chomping low bits of address for functions doing it by themselves,
fix whitespace, add a correctness checking.
I did this for remap-file-pages protection support, it was useful on its
own too.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Apparently, GDB gets confused when we do an execvp() on ourselves.
Since it's simply done to allocate further space for command line arguments
(which we'll use to allow gathering the startup command line for guest
processes through the host), allow the user to disable that to get a
debuggable UML binary.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This eliminates the segfault info ring buffer, which added a system call to
each page fault, and which hadn't been useful for debugging in ages.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It has been reported that the way Linux handles NODEFER for signals is
not consistent with the way other Unix boxes handle it. I've written a
program to test the behavior of how this flag affects signals and had
several reports from people who ran this on various Unix boxes,
confirming that Linux seems to be unique on the way this is handled.
The way NODEFER affects signals on other Unix boxes is as follows:
1) If NODEFER is set, other signals in sa_mask are still blocked.
2) If NODEFER is set and the signal is in sa_mask, then the signal is
still blocked. (Note: this is the behavior of all tested but Linux _and_
NetBSD 2.0 *).
The way NODEFER affects signals on Linux:
1) If NODEFER is set, other signals are _not_ blocked regardless of
sa_mask (Even NetBSD doesn't do this).
2) If NODEFER is set and the signal is in sa_mask, then the signal being
handled is not blocked.
The patch converts signal handling in all current Linux architectures to
the way most Unix boxes work.
Unix boxes that were tested: DU4, AIX 5.2, Irix 6.5, NetBSD 2.0, SFU
3.5 on WinXP, AIX 5.3, Mac OSX, and of course Linux 2.6.13-rcX.
* NetBSD was the only other Unix to behave like Linux on point #2. The
main concern was brought up by point #1 which even NetBSD isn't like
Linux. So with this patch, we leave NetBSD as the lonely one that
behaves differently here with #2.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Running UML inside a detached screen delivers SIGWINCH when UML is not
expecting it. This patch ignores them.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
update_process_times was missing its irq_enter/irq_exit wrapper. This caused
ksoftirqd to be scheduled on every clock tick.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
By this point, .is_user has already been set, so this assignment is useless.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
