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369842658a
This patch adds support for TIF_RESTORE_SIGMASK to ARM's
signal handling, which allows to hook up the pselect6, ppoll,
and epoll_pwait syscalls on ARM.
Tested here with eabi userspace and a test program with a
deliberate race between a child's exit and the parent's
sigprocmask/select sequence. Using sys_pselect6() instead
of sigprocmask/select reliably prevents the race.
The other arch's support for TIF_RESTORE_SIGMASK has evolved
over time:
In 2.6.16:
- add TIF_RESTORE_SIGMASK which parallels TIF_SIGPENDING
- test both when checking for pending signal [changed later]
- reimplement sys_sigsuspend() to use current->saved_sigmask,
TIF_RESTORE_SIGMASK [changed later], and -ERESTARTNOHAND;
ditto for sys_rt_sigsuspend(), but drop private code and
use common code via __ARCH_WANT_SYS_RT_SIGSUSPEND;
- there are now no "extra" calls to do_signal() so its oldset
parameter is always ¤t->blocked so need not be passed,
also its return value is changed to void
- change handle_signal() to return 0/-errno
- change do_signal() to honor TIF_RESTORE_SIGMASK:
+ get oldset from current->saved_sigmask if TIF_RESTORE_SIGMASK
is set
+ if handle_signal() was successful then clear TIF_RESTORE_SIGMASK
+ if no signal was delivered and TIF_RESTORE_SIGMASK is set then
clear it and restore the sigmask
- hook up sys_pselect6() and sys_ppoll()
In 2.6.19:
- hook up sys_epoll_pwait()
In 2.6.26:
- allow archs to override how TIF_RESTORE_SIGMASK is implemented;
default set_restore_sigmask() sets both TIF_RESTORE_SIGMASK and
TIF_SIGPENDING; archs need now just test TIF_SIGPENDING again
when checking for pending signal work; some archs now implement
TIF_RESTORE_SIGMASK as a secondary/non-atomic thread flag bit
- call set_restore_sigmask() in sys_sigsuspend() instead of setting
TIF_RESTORE_SIGMASK
In 2.6.29-rc:
- kill sys_pselect7() which no arch wanted
So for 2.6.31-rc6/ARM this patch does the following:
- Add TIF_RESTORE_SIGMASK. Use the generic set_restore_sigmask()
which sets both TIF_SIGPENDING and TIF_RESTORE_SIGMASK, so
TIF_RESTORE_SIGMASK need not claim one of the scarce low thread
flags, and existing TIF_SIGPENDING and _TIF_WORK_MASK tests need
not be extended for TIF_RESTORE_SIGMASK.
- sys_sigsuspend() is reimplemented to use current->saved_sigmask
and set_restore_sigmask(), making it identical to most other archs
- The private code for sys_rt_sigsuspend() is removed, instead
generic code supplies it via __ARCH_WANT_SYS_RT_SIGSUSPEND.
- sys_sigsuspend() and sys_rt_sigsuspend() no longer need a pt_regs
parameter, so their assembly code wrappers are removed.
- handle_signal() is changed to return 0 on success or -errno.
- The oldset parameter to do_signal() is now redundant and removed,
and the return value is now also redundant and changed to void.
- do_signal() is changed to honor TIF_RESTORE_SIGMASK:
+ get oldset from current->saved_sigmask if TIF_RESTORE_SIGMASK
is set
+ if handle_signal() was successful then clear TIF_RESTORE_SIGMASK
+ if no signal was delivered and TIF_RESTORE_SIGMASK is set then
clear it and restore the sigmask
- Hook up sys_pselect6, sys_ppoll, and sys_epoll_pwait.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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| .. | ||
| boot | ||
| common | ||
| configs | ||
| include/asm | ||
| kernel | ||
| lib | ||
| mach-aaec2000 | ||
| mach-at91 | ||
| mach-clps711x | ||
| mach-davinci | ||
| mach-ebsa110 | ||
| mach-ep93xx | ||
| mach-footbridge | ||
| mach-gemini | ||
| mach-h720x | ||
| mach-integrator | ||
| mach-iop13xx | ||
| mach-iop32x | ||
| mach-iop33x | ||
| mach-ixp4xx | ||
| mach-ixp23xx | ||
| mach-ixp2000 | ||
| mach-kirkwood | ||
| mach-ks8695 | ||
| mach-l7200 | ||
| mach-lh7a40x | ||
| mach-loki | ||
| mach-mmp | ||
| mach-msm | ||
| mach-mv78xx0 | ||
| mach-mx1 | ||
| mach-mx2 | ||
| mach-mx3 | ||
| mach-netx | ||
| mach-ns9xxx | ||
| mach-omap1 | ||
| mach-omap2 | ||
| mach-orion5x | ||
| mach-pnx4008 | ||
| mach-pxa | ||
| mach-realview | ||
| mach-rpc | ||
| mach-s3c24a0/include/mach | ||
| mach-s3c2400 | ||
| mach-s3c2410 | ||
| mach-s3c2412 | ||
| mach-s3c2440 | ||
| mach-s3c2442 | ||
| mach-s3c2443 | ||
| mach-s3c6400 | ||
| mach-s3c6410 | ||
| mach-sa1100 | ||
| mach-shark | ||
| mach-stmp37xx | ||
| mach-stmp378x | ||
| mach-u300 | ||
| mach-versatile | ||
| mach-w90x900 | ||
| mm | ||
| nwfpe | ||
| oprofile | ||
| plat-iop | ||
| plat-mxc | ||
| plat-omap | ||
| plat-orion | ||
| plat-pxa | ||
| plat-s3c | ||
| plat-s3c24xx | ||
| plat-s3c64xx | ||
| plat-stmp3xxx | ||
| tools | ||
| vfp | ||
| Kconfig | ||
| Kconfig-nommu | ||
| Kconfig.debug | ||
| Makefile | ||