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| author |   Helge Deller <deller@gmx.de> | 2021-12-08 11:06:52 +0100 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2022-03-11 19:49:30 +0100 |
| commit | df24e1783e6e0eb3dc0e3ba5a8df3bb0cc537408 (patch) | |
| tree | 73050ce6de41a1fd03e20bffa47c82fb598ef816 /arch/parisc/include/asm/processor.h | |
| parent | parisc: Simplify fast path for non-access data TLB faults (diff) | |
| download | linux-dev-df24e1783e6e0eb3dc0e3ba5a8df3bb0cc537408.tar.xz linux-dev-df24e1783e6e0eb3dc0e3ba5a8df3bb0cc537408.zip | |
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>
Diffstat (limited to 'arch/parisc/include/asm/processor.h')
| -rw-r--r-- | arch/parisc/include/asm/processor.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h index 3a3d05438408..006364212795 100644 --- a/arch/parisc/include/asm/processor.h +++ b/arch/parisc/include/asm/processor.h @@ -236,7 +236,7 @@ on downward growing arches, it looks like this: #define start_thread(regs, new_pc, new_sp) do { \ elf_addr_t *sp = (elf_addr_t *)new_sp; \ - __u32 spaceid = (__u32)current->mm->context; \ + __u32 spaceid = (__u32)current->mm->context.space_id; \ elf_addr_t pc = (elf_addr_t)new_pc | 3; \ elf_caddr_t *argv = (elf_caddr_t *)bprm->exec + 1; \ \ |