Thread (13 messages) 13 messages, 2 authors, 2023-02-15

Re: [PATCH v6 1/7] powerpc: mm: Separate set_pte, set_pte_at for internal, external use

From: Christophe Leroy <hidden>
Date: 2023-02-14 06:00:34


Le 14/02/2023 à 02:59, Rohan McLure a écrit :
quoted hunk ↗ jump to hunk
Produce separate symbols for set_pte, which is to be used in
arch/powerpc for reassignment of pte's, and set_pte_at, used in generic
code.

The reason for this distinction is to support the Page Table Check
sanitiser. Having this distinction allows for set_pte_at to
instrumented, but set_pte not to be, permitting for uninstrumented
internal mappings. This distinction in names is also present in x86.

Signed-off-by: Rohan McLure <redacted>
---
v6: new patch
---
  arch/powerpc/include/asm/book3s/pgtable.h | 4 ++--
  arch/powerpc/include/asm/nohash/pgtable.h | 4 ++--
  arch/powerpc/include/asm/pgtable.h        | 1 +
  arch/powerpc/mm/pgtable.c                 | 4 ++--
  4 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/pgtable.h b/arch/powerpc/include/asm/book3s/pgtable.h
index d18b748ea3ae..dbcdc2103c59 100644
--- a/arch/powerpc/include/asm/book3s/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/pgtable.h
@@ -12,8 +12,8 @@
  /* Insert a PTE, top-level function is out of line. It uses an inline
   * low level function in the respective pgtable-* files
   */
-extern void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
-		       pte_t pte);
+extern void set_pte(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
+		    pte_t pte);
Remove 'extern' keyword, it's pointless and deprecated, checkpatch 
--strict is likely complaining about it too.

Then have the protoype fit on a single line.
quoted hunk ↗ jump to hunk
  
  
  #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index 69c3a050a3d8..ac3e69a18253 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h
@@ -154,8 +154,8 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
  /* Insert a PTE, top-level function is out of line. It uses an inline
   * low level function in the respective pgtable-* files
   */
-extern void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
-		       pte_t pte);
+extern void set_pte(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
+		    pte_t pte);
Remove 'extern' keyword and have the protoype fit on a single line.

quoted hunk ↗ jump to hunk
  
  /* This low level function performs the actual PTE insertion
   * Setting the PTE depends on the MMU type and other factors. It's
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 9972626ddaf6..17d30359d1f4 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -48,6 +48,7 @@ struct mm_struct;
  /* Keep these as a macros to avoid include dependency mess */
  #define pte_page(x)		pfn_to_page(pte_pfn(x))
  #define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
+#define set_pte_at  		set_pte
  /*
   * Select all bits except the pfn
   */
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index cb2dcdb18f8e..e9a464e0d081 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -187,8 +187,8 @@ static pte_t set_access_flags_filter(pte_t pte, struct vm_area_struct *vma,
  /*
   * set_pte stores a linux PTE into the linux page table.
   */
-void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
-		pte_t pte)
+void set_pte(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
+	     pte_t pte)
Have it fit on a single line.
  {
  	/*
  	 * Make sure hardware valid bit is not set. We don't do
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