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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/pgtable.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/pgtable.h')
| -rw-r--r-- | arch/parisc/include/asm/pgtable.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h index 3e7cf882639f..f0393f00c2ff 100644 --- a/arch/parisc/include/asm/pgtable.h +++ b/arch/parisc/include/asm/pgtable.h @@ -70,7 +70,7 @@ static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr) unsigned long flags; purge_tlb_start(flags); - mtsp(mm->context, 1); + mtsp(mm->context.space_id, 1); pdtlb(addr); pitlb(addr); purge_tlb_end(flags); @@ -219,9 +219,10 @@ extern void __update_cache(pte_t pte); #define _PAGE_PRESENT (1 << xlate_pabit(_PAGE_PRESENT_BIT)) #define _PAGE_HUGE (1 << xlate_pabit(_PAGE_HPAGE_BIT)) #define _PAGE_USER (1 << xlate_pabit(_PAGE_USER_BIT)) +#define _PAGE_SPECIAL (_PAGE_DMB) #define _PAGE_TABLE (_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED) -#define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY) +#define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_SPECIAL) #define _PAGE_KERNEL_RO (_PAGE_PRESENT | _PAGE_READ | _PAGE_DIRTY | _PAGE_ACCESSED) #define _PAGE_KERNEL_EXEC (_PAGE_KERNEL_RO | _PAGE_EXEC) #define _PAGE_KERNEL_RWX (_PAGE_KERNEL_EXEC | _PAGE_WRITE) @@ -348,6 +349,7 @@ static inline void pud_clear(pud_t *pud) { static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; } static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; } static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; } +static inline int pte_special(pte_t pte) { return pte_val(pte) & _PAGE_SPECIAL; } static inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~_PAGE_DIRTY; return pte; } static inline pte_t pte_mkold(pte_t pte) { pte_val(pte) &= ~_PAGE_ACCESSED; return pte; } @@ -355,6 +357,7 @@ static inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) &= ~_PAGE_WRITE; ret static inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) |= _PAGE_DIRTY; return pte; } static inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) |= _PAGE_ACCESSED; return pte; } static inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) |= _PAGE_WRITE; return pte; } +static inline pte_t pte_mkspecial(pte_t pte) { pte_val(pte) |= _PAGE_SPECIAL; return pte; } /* * Huge pte definitions. |