linux/arch/parisc
Helge Deller df24e1783e parisc: Add vDSO support
Add minimal vDSO support, which provides the signal trampoline helpers,
but none of the userspace syscall helpers like time wrappers.

The big benefit of this vDSO implementation is, that we now don't need
an executeable stack any longer. PA-RISC is one of the last
architectures where an executeable stack was needed in oder to implement
the signal trampolines by putting assembly instructions on the stack
which then gets executed. Instead the kernel will provide the relevant
code in the vDSO page and only put the pointers to the signal
information on the stack.

By dropping the need for executable stacks we avoid running into issues
with applications which want non executable stacks for security reasons.
Additionally, alternative stacks on memory areas without exec
permissions are supported too.

This code is based on an initial implementation by Randolph Chung from 2006:
https://lore.kernel.org/linux-parisc/4544A34A.6080700@tausq.org/

I did the porting and lifted the code to current code base. Dave fixed
the unwind code so that gdb and glibc are able to backtrace through the
code. An additional patch to gdb will be pushed upstream by Dave.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Dave Anglin <dave.anglin@bell.net>
Cc: Randolph Chung <randolph@tausq.org>
Signed-off-by: Helge Deller <deller@gmx.de>
2022-03-11 19:49:30 +01:00
..
boot Kbuild updates for v5.17 2022-01-19 11:15:19 +02:00
configs parisc: Enable sata sil, audit and usb support on 64-bit defconfig 2021-11-30 21:49:32 +01:00
include parisc: Add vDSO support 2022-03-11 19:49:30 +01:00
kernel parisc: Add vDSO support 2022-03-11 19:49:30 +01:00
lib parisc: Add ioread64_lo_hi() and iowrite64_lo_hi() 2022-02-07 16:33:31 +01:00
math-emu parisc: math-emu: Fix fall-through warnings 2021-09-01 22:18:18 +02:00
mm parisc: Fix handling off probe non-access faults 2022-03-11 19:49:30 +01:00
defpalo.conf parisc: switch to gzip-compressed vmlinuz kernel 2013-07-09 22:09:20 +02:00
install.sh parisc: Fix "make install" on newer debian releases 2021-12-04 21:36:04 +01:00
Kbuild kbuild: use more subdir- for visiting subdirectories while cleaning 2021-10-24 13:49:46 +09:00
Kconfig parisc: Add vDSO support 2022-03-11 19:49:30 +01:00
Kconfig.debug tracing: Refactor TRACE_IRQFLAGS_SUPPORT in Kconfig 2021-08-16 11:37:21 -04:00
Makefile parisc: Add vDSO support 2022-03-11 19:49:30 +01:00
nm