[RFC PATCH 0/5]: Removing saved_sigmask
From: Eric W. Biederman
Date: Fri Jun 07 2019 - 17:44:29 EST
While reviewing Oleg's patches I realized a bunch of the logic around
saved_sigmask was redundant. So I dug just to see what I could see.
I turns out that real_blocked and saved_sigmask were different
implementations of the same idea for slightly different purposes.
Which means we only need either real_blocked or saved_sigmask.
I chose real_blocked as it has just a little bit of code associated
with it to disable optimizations on the signal sending path that do
not apply to blocked signals.
I did a little bit of cleanup of the users. Modified the core to keep
real_blocked in sync with blocked except while a clever system call that
like pselect or sigtimedwait is running.
After the dust cleared this allowed restore_sigmask and all of the logic
to keep it valid to be removed entirely.
I have only done the most cursory of testing at this point. Does anyone
have any thoughts in cleaning up the code in this direction?
Eric W. Biederman (5):
signal: Teach sigsuspend to use set_user_sigmask
signal/kvm: Stop using sigprocmask in kvm_sigset_(activate|deactivate)
signal: Always keep real_blocked in sync with blocked
signal: Remove saved_sigmask
signal: Remove the unnecessary restore_sigmask flag
arch/arc/include/asm/thread_info.h | 1 -
arch/arm/include/asm/thread_info.h | 1 -
arch/arm64/include/asm/thread_info.h | 1 -
arch/c6x/include/asm/thread_info.h | 1 -
arch/csky/include/asm/thread_info.h | 2 -
arch/h8300/include/asm/thread_info.h | 1 -
arch/hexagon/include/asm/thread_info.h | 1 -
arch/m68k/include/asm/thread_info.h | 1 -
arch/mips/include/asm/thread_info.h | 1 -
arch/nds32/include/asm/thread_info.h | 2 -
arch/nios2/include/asm/thread_info.h | 2 -
arch/riscv/include/asm/thread_info.h | 1 -
arch/s390/include/asm/thread_info.h | 1 -
arch/sparc/include/asm/thread_info_32.h | 1 -
arch/um/include/asm/thread_info.h | 1 -
arch/unicore32/include/asm/thread_info.h | 1 -
arch/xtensa/include/asm/thread_info.h | 1 -
include/linux/sched.h | 5 --
include/linux/sched/signal.h | 84 +-------------------------------
kernel/ptrace.c | 15 ++----
kernel/signal.c | 56 +++++++++------------
virt/kvm/kvm_main.c | 11 +----
22 files changed, 31 insertions(+), 160 deletions(-)