[PATCH v1 1/8] powerpc/lib/code-patching: Enhance code patching
christophe leroy
christophe.leroy at c-s.fr
Mon May 29 00:29:06 AEST 2017
Le 25/05/2017 à 05:36, Balbir Singh a écrit :
> Today our patching happens via direct copy and
> patch_instruction. The patching code is well
> contained in the sense that copying bits are limited.
>
> While considering implementation of CONFIG_STRICT_RWX,
> the first requirement is to a create another mapping
> that will allow for patching. We create the window using
> text_poke_area, allocated via get_vm_area(), which might
> be an overkill. We can do per-cpu stuff as well. The
> downside of these patches that patch_instruction is
> now synchornized using a lock. Other arches do similar
> things, but use fixmaps. The reason for not using
> fixmaps is to make use of any randomization in the
> future. The code also relies on set_pte_at and pte_clear
> to do the appropriate tlb flushing.
>
> Signed-off-by: Balbir Singh <bsingharora at gmail.com>
[...]
> +static int kernel_map_addr(void *addr)
> +{
> + unsigned long pfn;
> int err;
>
> - __put_user_size(instr, addr, 4, err);
> + if (is_vmalloc_addr(addr))
> + pfn = vmalloc_to_pfn(addr);
> + else
> + pfn = __pa_symbol(addr) >> PAGE_SHIFT;
> +
> + err = map_kernel_page((unsigned long)text_poke_area->addr,
> + (pfn << PAGE_SHIFT), _PAGE_KERNEL_RW | _PAGE_PRESENT);
map_kernel_page() doesn't exist on powerpc32, so compilation fails.
However a similar function exists and is called map_page()
Maybe the below modification could help (not tested yet)
Christophe
---
arch/powerpc/include/asm/book3s/32/pgtable.h | 2 ++
arch/powerpc/include/asm/nohash/32/pgtable.h | 2 ++
arch/powerpc/mm/8xx_mmu.c | 2 +-
arch/powerpc/mm/dma-noncoherent.c | 2 +-
arch/powerpc/mm/mem.c | 4 ++--
arch/powerpc/mm/mmu_decl.h | 1 -
arch/powerpc/mm/pgtable_32.c | 8 ++++----
7 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h
b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 26ed228..7fb7558 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -297,6 +297,8 @@ static inline void __ptep_set_access_flags(struct
mm_struct *mm,
extern int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t
**ptep,
pmd_t **pmdp);
+int map_kernel_page(unsigned long va, phys_addr_t pa, int flags);
+
/* Generic accessors to PTE bits */
static inline int pte_write(pte_t pte) { return !!(pte_val(pte) &
_PAGE_RW);}
static inline int pte_dirty(pte_t pte) { return !!(pte_val(pte) &
_PAGE_DIRTY); }
diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h
b/arch/powerpc/include/asm/nohash/32/pgtable.h
index 5134ade..9131426 100644
--- a/arch/powerpc/include/asm/nohash/32/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/32/pgtable.h
@@ -340,6 +340,8 @@ static inline void __ptep_set_access_flags(struct
mm_struct *mm,
extern int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t
**ptep,
pmd_t **pmdp);
+int map_kernel_page(unsigned long va, phys_addr_t pa, int flags);
+
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_POWERPC_NOHASH_32_PGTABLE_H */
diff --git a/arch/powerpc/mm/8xx_mmu.c b/arch/powerpc/mm/8xx_mmu.c
index 6c5025e..f4c6472 100644
--- a/arch/powerpc/mm/8xx_mmu.c
+++ b/arch/powerpc/mm/8xx_mmu.c
@@ -88,7 +88,7 @@ static void mmu_mapin_immr(void)
int offset;
for (offset = 0; offset < IMMR_SIZE; offset += PAGE_SIZE)
- map_page(v + offset, p + offset, f);
+ map_kernel_page(v + offset, p + offset, f);
}
/* Address of instructions to patch */
diff --git a/arch/powerpc/mm/dma-noncoherent.c
b/arch/powerpc/mm/dma-noncoherent.c
index 2dc74e5..3825284 100644
--- a/arch/powerpc/mm/dma-noncoherent.c
+++ b/arch/powerpc/mm/dma-noncoherent.c
@@ -227,7 +227,7 @@ __dma_alloc_coherent(struct device *dev, size_t
size, dma_addr_t *handle, gfp_t
do {
SetPageReserved(page);
- map_page(vaddr, page_to_phys(page),
+ map_kernel_page(vaddr, page_to_phys(page),
pgprot_val(pgprot_noncached(PAGE_KERNEL)));
page++;
vaddr += PAGE_SIZE;
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 9ee536e..04f4c98 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -313,11 +313,11 @@ void __init paging_init(void)
unsigned long end = __fix_to_virt(FIX_HOLE);
for (; v < end; v += PAGE_SIZE)
- map_page(v, 0, 0); /* XXX gross */
+ map_kernel_page(v, 0, 0); /* XXX gross */
#endif
#ifdef CONFIG_HIGHMEM
- map_page(PKMAP_BASE, 0, 0); /* XXX gross */
+ map_kernel_page(PKMAP_BASE, 0, 0); /* XXX gross */
pkmap_page_table = virt_to_kpte(PKMAP_BASE);
kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index f988db6..d46128b 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -94,7 +94,6 @@ extern void _tlbia(void);
#ifdef CONFIG_PPC32
extern void mapin_ram(void);
-extern int map_page(unsigned long va, phys_addr_t pa, int flags);
extern void setbat(int index, unsigned long virt, phys_addr_t phys,
unsigned int size, pgprot_t prot);
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index a65c0b4..9c23c09 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -189,7 +189,7 @@ __ioremap_caller(phys_addr_t addr, unsigned long
size, unsigned long flags,
err = 0;
for (i = 0; i < size && err == 0; i += PAGE_SIZE)
- err = map_page(v+i, p+i, flags);
+ err = map_kernel_page(v+i, p+i, flags);
if (err) {
if (slab_is_available())
vunmap((void *)v);
@@ -215,7 +215,7 @@ void iounmap(volatile void __iomem *addr)
}
EXPORT_SYMBOL(iounmap);
-int map_page(unsigned long va, phys_addr_t pa, int flags)
+int map_kernel_page(unsigned long va, phys_addr_t pa, int flags)
{
pmd_t *pd;
pte_t *pg;
@@ -255,7 +255,7 @@ void __init __mapin_ram_chunk(unsigned long offset,
unsigned long top)
ktext = ((char *)v >= _stext && (char *)v < etext) ||
((char *)v >= _sinittext && (char *)v < _einittext);
f = ktext ? pgprot_val(PAGE_KERNEL_TEXT) : pgprot_val(PAGE_KERNEL);
- map_page(v, p, f);
+ map_kernel_page(v, p, f);
#ifdef CONFIG_PPC_STD_MMU_32
if (ktext)
hash_preload(&init_mm, v, 0, 0x300);
@@ -387,7 +387,7 @@ void __set_fixmap (enum fixed_addresses idx,
phys_addr_t phys, pgprot_t flags)
return;
}
- map_page(address, phys, pgprot_val(flags));
+ map_kernel_page(address, phys, pgprot_val(flags));
fixmaps++;
}
--
2.2.2
---
L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
https://www.avast.com/antivirus
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