linux_dsm_epyc7002/arch
Sam bobroff feba40362b powerpc/tm: Abort syscalls in active transactions
This patch changes the syscall handler to doom (tabort) active
transactions when a syscall is made and return immediately without
performing the syscall.

Currently, the system call instruction automatically suspends an
active transaction which causes side effects to persist when an active
transaction fails.

This does change the kernel's behaviour, but in a way that was
documented as unsupported. It doesn't reduce functionality because
syscalls will still be performed after tsuspend. It also provides a
consistent interface and makes the behaviour of user code
substantially the same across powerpc and platforms that do not
support suspended transactions (e.g. x86 and s390).

Performance measurements using
http://ozlabs.org/~anton/junkcode/null_syscall.c
indicate the cost of a system call increases by about 0.5%.

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Acked-By: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-04-11 20:49:19 +10:00
..
alpha asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
arc ARC: Fix thread_saved_pc() 2015-02-27 10:59:34 +05:30
arm The clk fixes for 4.0-rc4 comprise three themes. First are the usual 2015-03-15 15:07:08 -07:00
arm64 arm64 fixes: 2015-03-14 09:32:00 -07:00
avr32 asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
blackfin Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2015-02-21 12:59:04 -08:00
c6x arch/c6x/include/asm/pgtable.h: define dummy pgprot_writecombine for !MMU 2015-03-12 18:46:08 -07:00
cris CRIS changes for 3.20 2015-02-15 18:02:02 -08:00
frv mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28 09:57:51 -08:00
hexagon all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
ia64 asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
m32r mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28 09:57:51 -08:00
m68k mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28 09:57:51 -08:00
metag metag: Fix KSTK_EIP() and KSTK_ESP() macros 2015-02-24 12:54:21 +00:00
microblaze microblaze: Fix syscall error recovery for invalid syscall IDs 2015-03-04 15:12:27 +01:00
mips KVM: MIPS: Enable after disabling interrupt 2015-03-02 19:18:12 -03:00
mn10300 mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28 09:57:51 -08:00
nios2 nios2: update pt_regs 2015-03-12 13:35:06 +08:00
openrisc asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
parisc mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28 09:57:51 -08:00
powerpc powerpc/tm: Abort syscalls in active transactions 2015-04-11 20:49:19 +10:00
s390 Merge git://git.kernel.org/pub/scm/virt/kvm/kvm 2015-03-09 18:59:50 -07:00
score all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
sh asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
sparc asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
tile tile: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:37 -08:00
um all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
unicore32 mm: vmalloc: pass additional vm_flags to __vmalloc_node_range() 2015-02-13 21:21:42 -08:00
x86 xen: bug fixes for 4.0-rc3 2015-03-13 13:34:38 -07:00
xtensa asm-generic: uaccess.h cleanup 2015-02-18 10:02:24 -08:00
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