linux/arch/s390/mm
Sven Schnelle 56e62a7370 s390: convert to generic entry
This patch converts s390 to use the generic entry infrastructure from
kernel/entry/*.

There are a few special things on s390:

- PIF_PER_TRAP is moved to TIF_PER_TRAP as the generic code doesn't
  know about our PIF flags in exit_to_user_mode_loop().

- The old code had several ways to restart syscalls:

  a) PIF_SYSCALL_RESTART, which was only set during execve to force a
     restart after upgrading a process (usually qemu-kvm) to pgste page
     table extensions.

  b) PIF_SYSCALL, which is set by do_signal() to indicate that the
     current syscall should be restarted. This is changed so that
     do_signal() now also uses PIF_SYSCALL_RESTART. Continuing to use
     PIF_SYSCALL doesn't work with the generic code, and changing it
     to PIF_SYSCALL_RESTART makes PIF_SYSCALL and PIF_SYSCALL_RESTART
     more unique.

- On s390 calling sys_sigreturn or sys_rt_sigreturn is implemented by
executing a svc instruction on the process stack which causes a fault.
While handling that fault the fault code sets PIF_SYSCALL to hand over
processing to the syscall code on exit to usermode.

The patch introduces PIF_SYSCALL_RET_SET, which is set if ptrace sets
a return value for a syscall. The s390x ptrace ABI uses r2 both for the
syscall number and return value, so ptrace cannot set the syscall number +
return value at the same time. The flag makes handling that a bit easier.
do_syscall() will just skip executing the syscall if PIF_SYSCALL_RET_SET
is set.

CONFIG_DEBUG_ASCE was removd in favour of the generic CONFIG_DEBUG_ENTRY.
CR1/7/13 will be checked both on kernel entry and exit to contain the
correct asces.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-01-19 12:29:26 +01:00
..
cmm.c mm: remove unneeded includes of <asm/pgalloc.h> 2020-08-07 11:33:26 -07:00
dump_pagetables.c s390: unify identity mapping limits handling 2020-11-20 19:19:10 +01:00
extmem.c s390/extmem: remove stale -ENOSPC comment and handling 2020-07-03 10:49:16 +02:00
fault.c s390: convert to generic entry 2021-01-19 12:29:26 +01:00
gmap.c ARM: 2020-12-20 10:44:05 -08:00
hugetlbpage.c s390/mm: fix huge pte soft dirty copying 2020-07-09 15:18:23 +02:00
init.c s390/mm: use invalid asce instead of kernel asce 2020-11-23 12:01:12 +01:00
kasan_init.c s390: unify identity mapping limits handling 2020-11-20 19:19:10 +01:00
maccess.c s390/maccess: add no DAT mode to kernel_write 2020-06-29 16:26:36 +02:00
Makefile s390: add ARCH_HAS_DEBUG_WX support 2020-09-14 11:38:35 +02:00
mmap.c mm: remove unneeded includes of <asm/pgalloc.h> 2020-08-07 11:33:26 -07:00
page-states.c arch, mm: replace for_each_memblock() with for_each_mem_pfn_range() 2020-10-13 18:38:35 -07:00
pageattr.c s390/mm,ptdump: hold cpa mutex while walking for kernel page table dump 2020-09-14 11:38:34 +02:00
pgalloc.c s390/mm: remove set_fs / rework address space handling 2020-11-23 12:01:12 +01:00
pgtable.c s390/pci: Implement ioremap_wc/prot() with MIO 2020-09-14 10:30:07 +02:00
vmem.c s390/vmem: make variable and function names consistent 2020-11-20 19:19:12 +01:00