Commit Graph

10 Commits

Author SHA1 Message Date
Willem Pinckaers 7f151e6f71 coroutine-sigaltstack: Change jmp_buf to sigjmp_buf
This is a simple patch to change the type of old_env from jmp_buf
to sigjmp_buf.  old_env is used by sigsetjmp and as such should be
a sigjmp_buf.

This fixes a stack_chk fail in a OSX 32bit build. Since at least on
OSX sigjmp_buf is four bytes larger then a jmpbuf, resulting in an
overflow in sigsetjmp. Due to variable reordering this overwrites
the stack cookie.

Signed-off-by: Willem Pinckaers <willem_qemu@lekkertech.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Peter: I think I must have missed this one when I converted
       all the jmp_buf to sigjmp_buf in commit 6ab7e546.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2014-11-11 11:07:55 +03:00
Anthony Liguori 864a556e9a Merge remote-tracking branch 'kwolf/for-anthony' into staging
# By Paolo Bonzini (7) and others
# Via Kevin Wolf
* kwolf/for-anthony: (22 commits)
  pc: add compatibility machine types for 1.4
  blockdev: enable discard by default
  qemu-nbd: add --discard option
  blockdev: add discard suboption to -drive
  block: implement BDRV_O_UNMAP
  block: complete all IOs before .bdrv_truncate
  coroutine: trim down nesting level in perf_nesting test
  coroutine: move pooling to common code
  qemu-iotests: Test qcow2 image creation options
  qemu-iotests: Add qemu-img compare test
  qemu-img: Add compare subcommand
  qemu-img: Add "Quiet mode" option
  block: Add synchronous wrapper for bdrv_co_is_allocated_above
  block: refuse negative iops and bps values
  block: use Error in do_check_io_limits()
  qcow2: support compressed clusters in BlockFragInfo
  qemu-img: add compressed clusters to BlockFragInfo
  qemu-img: fix missing space in qemu-img check output
  qcow2: record fragmentation statistics during check
  qcow2: introduce check_refcounts_l1/l2() flags
  ...
2013-02-26 07:44:39 -06:00
Peter Maydell 6ab7e5465a Replace all setjmp()/longjmp() with sigsetjmp()/siglongjmp()
The setjmp() function doesn't specify whether signal masks are saved and
restored; on Linux they are not, but on BSD (including MacOSX) they are.
We want to have consistent behaviour across platforms, so we should
always use "don't save/restore signal mask" (this is also generally
going to be faster). This also works around a bug in MacOSX where the
signal-restoration on longjmp() affects the signal mask for a completely
different thread, not just the mask for the thread which did the longjmp.
The most visible effect of this was that ctrl-C was ignored on MacOSX
because the CPU thread did a longjmp which resulted in its signal mask
being applied to every thread, so that all threads had SIGINT and SIGTERM
blocked.

The POSIX-sanctioned portable way to do a jump without affecting signal
masks is to siglongjmp() to a sigjmp_buf which was created by calling
sigsetjmp() with a zero savemask parameter, so change all uses of
setjmp()/longjmp() accordingly. [Technically POSIX allows sigsetjmp(buf, 0)
to save the signal mask; however the following siglongjmp() must not
restore the signal mask, so the pair can be effectively considered as
"sigjmp/longjmp which don't touch the mask".]

For Windows we provide a trivial sigsetjmp/siglongjmp in terms of
setjmp/longjmp -- this is OK because no user will ever pass a non-zero
savemask.

The setjmp() uses in tests/tcg/test-i386.c and tests/tcg/linux-test.c
are left untouched because these are self-contained singlethreaded
test programs intended to be run under QEMU's Linux emulation, so they
have neither the portability nor the multithreading issues to deal with.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Tested-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2013-02-23 16:11:19 +00:00
Paolo Bonzini 402397843e coroutine: move pooling to common code
The coroutine pool code is duplicated between the ucontext and
sigaltstack backends, and absent from the win32 backend.  But the
code can be shared easily by moving it to qemu-coroutine.c.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-02-22 21:21:10 +01:00
Paolo Bonzini 737e150e89 block: move include files to include/block/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:31 +01:00
Peter Maydell 2ad2210a7d coroutine-sigaltstack.c: Use stack_t, not struct sigaltstack
Use the POSIX-specified stack_t type as the argument to sigaltstack()
rather than the legacy struct sigaltstack. This allows us to compile
on MacOSX with --with-coroutine=sigaltstack.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-11-30 11:33:24 +01:00
Anthony Liguori 9cc31772bf Merge remote-tracking branch 'kwolf/for-anthony' into staging
* kwolf/for-anthony:
  qemu-img: Fix segmentation fault
  qcow2: Don't ignore failure to clear autoclear flags
  coroutine: Fix setup of sigaltstack coroutines
2012-05-14 12:45:01 -05:00
Jan Kiszka 99b5beba2f coroutine: Fix setup of sigaltstack coroutines
Use pthread_kill instead of process-wide kill to invoke the signal
handler used for stack switching. This may fix spurious lock-ups with
this backend, easily triggerable by extending the time window between
kill and sigsuspend.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-14 17:02:19 +02:00
Jim Meyering a31f053129 fix some common typos
These were identified using: http://github.com/lyda/misspell-check
and run like this to create a bourne shell script using GNU sed's
-i option:

git ls-files|grep -vF .bin | misspellings -f - |grep -v '^ERROR:' |perl \
-pe 's/^(.*?)\[(\d+)\]: (\w+) -> "(.*?)"$/sed -i '\''${2}s!$3!$4!'\'' $1/'

Manually eliding the FP, "rela->real" and resolving "addres" to
address (not "adders") we get this:

  sed -i '450s!thru!through!' Changelog
  sed -i '260s!neccessary!necessary!' coroutine-sigaltstack.c
  sed -i '54s!miniscule!minuscule!' disas.c
  sed -i '1094s!thru!through!' hw/usb/hcd-ehci.c
  sed -i '1095s!thru!through!' hw/usb/hcd-ehci.c
  sed -i '21s!unecessary!unnecessary!' qapi-schema-guest.json
  sed -i '307s!explictly!explicitly!' qemu-ga.c
  sed -i '490s!preceeding!preceding!' qga/commands-posix.c
  sed -i '792s!addres!address!' qga/commands-posix.c
  sed -i '6s!beeing!being!' tests/tcg/test-mmap.c

Also, manually fix "arithmentic", spotted by Peter Maydell:

  sed -i 's!arithmentic!arithmetic!' coroutine-sigaltstack.c

Signed-off-by: Jim Meyering <meyering@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
2012-05-14 07:27:24 +02:00
Alex Barcelo 3194c8ceeb coroutine: adding sigaltstack method (.c source)
This file is based in both coroutine-ucontext.c and
pth_mctx.c (from the GNU Portable Threads library).

The mechanism used to change stacks is the sigaltstack
function (variant 2 of the pth library).

v2: Some corrections. Moving global variables into
thread storage (CoroutineThreadState).

Signed-off-by: Alex Barcelo <abarcelo@ac.upc.edu>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-03-12 15:14:07 +01:00