[GIT PULL] parisc fixes for 3.8-rc7

From: James Bottomley
Date: Wed Feb 13 2013 - 00:01:49 EST


This is a couple of patches, one to fix a broken build with HPUX
compatibility and the other to solve a coherency problem we've been
seeing in our TLB where setting a page read only occasionally fails to
trigger a COW because of a stale writeable TLB entry.

The patches are here:

git://git.kernel.org/pub/scm/linux/kernel/git/jejb/parisc-2.6.git parisc-fixes

The short changelog is:

Geert Uytterhoeven (1):
hpux: Remove obsolete regs parameter from do_execve() in hpux_execve()

John David Anglin (1):
Purge existing TLB entries in set_pte_at and ptep_set_wrprotect

and the diffstat:

arch/parisc/hpux/fs.c | 3 +--
arch/parisc/include/asm/pgtable.h | 13 ++++++++++---
arch/parisc/kernel/cache.c | 18 ++++++++++++++++++
3 files changed, 29 insertions(+), 5 deletions(-)

Full diff is attached below.

James

---

diff --git a/arch/parisc/hpux/fs.c b/arch/parisc/hpux/fs.c
index a0760b8..838b479 100644
--- a/arch/parisc/hpux/fs.c
+++ b/arch/parisc/hpux/fs.c
@@ -43,8 +43,7 @@ int hpux_execve(struct pt_regs *regs)

error = do_execve(filename->name,
(const char __user *const __user *) regs->gr[25],
- (const char __user *const __user *) regs->gr[24],
- regs);
+ (const char __user *const __user *) regs->gr[24]);

putname(filename);

diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
index ee99f23..7df49fa 100644
--- a/arch/parisc/include/asm/pgtable.h
+++ b/arch/parisc/include/asm/pgtable.h
@@ -12,11 +12,10 @@

#include <linux/bitops.h>
#include <linux/spinlock.h>
+#include <linux/mm_types.h>
#include <asm/processor.h>
#include <asm/cache.h>

-struct vm_area_struct;
-
/*
* kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
* memory. For the return value to be meaningful, ADDR must be >=
@@ -40,7 +39,14 @@ struct vm_area_struct;
do{ \
*(pteptr) = (pteval); \
} while(0)
-#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
+
+extern void purge_tlb_entries(struct mm_struct *, unsigned long);
+
+#define set_pte_at(mm, addr, ptep, pteval) \
+ do { \
+ set_pte(ptep, pteval); \
+ purge_tlb_entries(mm, addr); \
+ } while (0)

#endif /* !__ASSEMBLY__ */

@@ -466,6 +472,7 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
old = pte_val(*ptep);
new = pte_val(pte_wrprotect(__pte (old)));
} while (cmpxchg((unsigned long *) ptep, old, new) != old);
+ purge_tlb_entries(mm, addr);
#else
pte_t old_pte = *ptep;
set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 48e16dc..b89a85a 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -419,6 +419,24 @@ void kunmap_parisc(void *addr)
EXPORT_SYMBOL(kunmap_parisc);
#endif

+void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
+{
+ unsigned long flags;
+
+ /* Note: purge_tlb_entries can be called at startup with
+ no context. */
+
+ /* Disable preemption while we play with %sr1. */
+ preempt_disable();
+ mtsp(mm->context, 1);
+ purge_tlb_start(flags);
+ pdtlb(addr);
+ pitlb(addr);
+ purge_tlb_end(flags);
+ preempt_enable();
+}
+EXPORT_SYMBOL(purge_tlb_entries);
+
void __flush_tlb_range(unsigned long sid, unsigned long start,
unsigned long end)
{


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