On LoongArch kmalloc() range is DMW-mapped rather than TLB-mapped, so
KFENCE remap __kfence_pool to the TLB-mappd range.
To make all drivers work, {virt, phys, page, pfn} translation functions
are overriden (part of them already done, others done in this series):
1, virt_to_pfn()/pfn_to_virt();
2, virt_to_page()/page_to_virt();
3, virt_to_phys()/phys_to_virt().
Since LoongArch overrides page_to_virt() which use page_address() in the
KFENCE case (by defining WANT_PAGE_VIRTUAL/HASHED_PAGE_VIRTUAL). So move
lowmem_page_address() a little later to avoid such build errors:
error: implicit declaration of function ‘page_address’.
Huacai Chen(3):
mm: Move lowmem_page_address() a little later.
LoongArch: Make {virt, phys, page, pfn} translation work with KFENCE
LoongArch: Make virt_addr_valid()/__virt_addr_valid() work with KFENCE
Signed-off-by: Huacai Chen <[email protected]>
---
2.27.0
When enabling both CONFIG_KFENCE and CONFIG_DEBUG_SG, I get the
following backtraces when running LongArch kernels.
[ 2.496257] kernel BUG at include/linux/scatterlist.h:187!
..
[ 2.501925] Call Trace:
[ 2.501950] [<9000000004ad59c4>] sg_init_one+0xac/0xc0
[ 2.502204] [<9000000004a438f8>] do_test_kpp+0x278/0x6e4
[ 2.502353] [<9000000004a43dd4>] alg_test_kpp+0x70/0xf4
[ 2.502494] [<9000000004a41b48>] alg_test+0x128/0x690
[ 2.502631] [<9000000004a3d898>] cryptomgr_test+0x20/0x40
[ 2.502775] [<90000000041b4508>] kthread+0x138/0x158
[ 2.502912] [<9000000004161c48>] ret_from_kernel_thread+0xc/0xa4
The backtrace is always similar but not exactly the same. It is always
triggered from cryptomgr_test, but not always from the same test.
Analysis shows that with CONFIG_KFENCE active, the address returned from
kmalloc() and friends is not always below vm_map_base. It is allocated
by kfence_alloc() which at least sometimes seems to get its memory from
an address space above vm_map_base. This causes __virt_addr_valid() to
return false for the affected objects.
Let __virt_addr_valid() return 1 for kfence pool addresses, this make
virt_addr_valid()/__virt_addr_valid() work with KFENCE.
Reported-by: Guenter Roeck <[email protected]>
Suggested-by: Guenter Roeck <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>
---
arch/loongarch/mm/mmap.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/loongarch/mm/mmap.c b/arch/loongarch/mm/mmap.c
index a9630a81b38a..89af7c12e8c0 100644
--- a/arch/loongarch/mm/mmap.c
+++ b/arch/loongarch/mm/mmap.c
@@ -4,6 +4,7 @@
*/
#include <linux/export.h>
#include <linux/io.h>
+#include <linux/kfence.h>
#include <linux/memblock.h>
#include <linux/mm.h>
#include <linux/mman.h>
@@ -111,6 +112,9 @@ int __virt_addr_valid(volatile void *kaddr)
{
unsigned long vaddr = (unsigned long)kaddr;
+ if (is_kfence_address((void *)kaddr))
+ return 1;
+
if ((vaddr < PAGE_OFFSET) || (vaddr >= vm_map_base))
return 0;
--
2.43.0
LoongArch will override page_to_virt() which use page_address() in the
KFENCE case (by defining WANT_PAGE_VIRTUAL/HASHED_PAGE_VIRTUAL). So move
lowmem_page_address() a little later to avoid such build errors:
error: implicit declaration of function 'page_address'.
Signed-off-by: Huacai Chen <[email protected]>
---
include/linux/mm.h | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0436b919f1c7..7b0ee64225de 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2207,11 +2207,6 @@ static inline int arch_make_folio_accessible(struct folio *folio)
*/
#include <linux/vmstat.h>
-static __always_inline void *lowmem_page_address(const struct page *page)
-{
- return page_to_virt(page);
-}
-
#if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
#define HASHED_PAGE_VIRTUAL
#endif
@@ -2234,6 +2229,11 @@ void set_page_address(struct page *page, void *virtual);
void page_address_init(void);
#endif
+static __always_inline void *lowmem_page_address(const struct page *page)
+{
+ return page_to_virt(page);
+}
+
#if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
#define page_address(page) lowmem_page_address(page)
#define set_page_address(page, address) do { } while(0)
--
2.43.0
KFENCE changes virt_to_page() to be able to translate tlb mapped virtual
addresses, but forget to change virt_to_phys()/phys_to_virt() and other
translation functions as well. This patch fix it, otherwise some drivers
(such as nvme and virtio-blk) cannot work with KFENCE.
All {virt, phys, page, pfn} translation functions are updated:
1, virt_to_pfn()/pfn_to_virt();
2, virt_to_page()/page_to_virt();
3, virt_to_phys()/phys_to_virt().
DMW/TLB mapped addresses are distinguished by comparing the vaddress
with vm_map_base in virt_to_xyz(), and we define WANT_PAGE_VIRTUAL in
the KFENCE case for the reverse translations, xyz_to_virt().
Signed-off-by: Huacai Chen <[email protected]>
---
arch/loongarch/include/asm/io.h | 20 +++++++++++++++-----
arch/loongarch/include/asm/kfence.h | 9 +++++++++
arch/loongarch/include/asm/page.h | 26 +++++++++++++++++++++++++-
arch/loongarch/mm/pgtable.c | 4 ++--
4 files changed, 51 insertions(+), 8 deletions(-)
diff --git a/arch/loongarch/include/asm/io.h b/arch/loongarch/include/asm/io.h
index 4a8adcca329b..c2f9979b2979 100644
--- a/arch/loongarch/include/asm/io.h
+++ b/arch/loongarch/include/asm/io.h
@@ -14,11 +14,6 @@
#include <asm/pgtable-bits.h>
#include <asm/string.h>
-/*
- * Change "struct page" to physical address.
- */
-#define page_to_phys(page) ((phys_addr_t)page_to_pfn(page) << PAGE_SHIFT)
-
extern void __init __iomem *early_ioremap(u64 phys_addr, unsigned long size);
extern void __init early_iounmap(void __iomem *addr, unsigned long size);
@@ -73,6 +68,21 @@ extern void __memcpy_fromio(void *to, const volatile void __iomem *from, size_t
#define __io_aw() mmiowb()
+#ifdef CONFIG_KFENCE
+#define virt_to_phys(kaddr) \
+({ \
+ (likely((unsigned long)kaddr < vm_map_base)) ? __pa((unsigned long)kaddr) : \
+ page_to_phys(tlb_virt_to_page((unsigned long)kaddr)) + offset_in_page((unsigned long)kaddr);\
+})
+
+#define phys_to_virt(paddr) \
+({ \
+ extern char *__kfence_pool; \
+ (unlikely(__kfence_pool == NULL)) ? __va((unsigned long)paddr) : \
+ page_address(phys_to_page((unsigned long)paddr)) + offset_in_page((unsigned long)paddr);\
+})
+#endif
+
#include <asm-generic/io.h>
#define ARCH_HAS_VALID_PHYS_ADDR_RANGE
diff --git a/arch/loongarch/include/asm/kfence.h b/arch/loongarch/include/asm/kfence.h
index 6c82aea1c993..a6a5760da3a3 100644
--- a/arch/loongarch/include/asm/kfence.h
+++ b/arch/loongarch/include/asm/kfence.h
@@ -16,6 +16,7 @@
static inline bool arch_kfence_init_pool(void)
{
int err;
+ char *kaddr, *vaddr;
char *kfence_pool = __kfence_pool;
struct vm_struct *area;
@@ -35,6 +36,14 @@ static inline bool arch_kfence_init_pool(void)
return false;
}
+ kaddr = kfence_pool;
+ vaddr = __kfence_pool;
+ while (kaddr < kfence_pool + KFENCE_POOL_SIZE) {
+ set_page_address(virt_to_page(kaddr), vaddr);
+ kaddr += PAGE_SIZE;
+ vaddr += PAGE_SIZE;
+ }
+
return true;
}
diff --git a/arch/loongarch/include/asm/page.h b/arch/loongarch/include/asm/page.h
index 44027060c54a..e85df33f11c7 100644
--- a/arch/loongarch/include/asm/page.h
+++ b/arch/loongarch/include/asm/page.h
@@ -78,7 +78,26 @@ typedef struct { unsigned long pgprot; } pgprot_t;
struct page *dmw_virt_to_page(unsigned long kaddr);
struct page *tlb_virt_to_page(unsigned long kaddr);
-#define virt_to_pfn(kaddr) PFN_DOWN(PHYSADDR(kaddr))
+#define pfn_to_phys(pfn) __pfn_to_phys(pfn)
+#define phys_to_pfn(paddr) __phys_to_pfn(paddr)
+
+#define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
+#define phys_to_page(paddr) pfn_to_page(phys_to_pfn(paddr))
+
+#ifndef CONFIG_KFENCE
+
+#define page_to_virt(page) __va(page_to_phys(page))
+#define virt_to_page(kaddr) phys_to_page(__pa(kaddr))
+
+#else
+
+#define WANT_PAGE_VIRTUAL
+
+#define page_to_virt(page) \
+({ \
+ extern char *__kfence_pool; \
+ (__kfence_pool == NULL) ? __va(page_to_phys(page)) : page_address(page); \
+})
#define virt_to_page(kaddr) \
({ \
@@ -86,6 +105,11 @@ struct page *tlb_virt_to_page(unsigned long kaddr);
dmw_virt_to_page((unsigned long)kaddr) : tlb_virt_to_page((unsigned long)kaddr);\
})
+#endif
+
+#define pfn_to_virt(pfn) page_to_virt(pfn_to_page(pfn))
+#define virt_to_pfn(kaddr) page_to_pfn(virt_to_page(kaddr))
+
extern int __virt_addr_valid(volatile void *kaddr);
#define virt_addr_valid(kaddr) __virt_addr_valid((volatile void *)(kaddr))
diff --git a/arch/loongarch/mm/pgtable.c b/arch/loongarch/mm/pgtable.c
index 2aae72e63871..bda018150000 100644
--- a/arch/loongarch/mm/pgtable.c
+++ b/arch/loongarch/mm/pgtable.c
@@ -11,13 +11,13 @@
struct page *dmw_virt_to_page(unsigned long kaddr)
{
- return pfn_to_page(virt_to_pfn(kaddr));
+ return phys_to_page(__pa(kaddr));
}
EXPORT_SYMBOL(dmw_virt_to_page);
struct page *tlb_virt_to_page(unsigned long kaddr)
{
- return pfn_to_page(pte_pfn(*virt_to_kpte(kaddr)));
+ return phys_to_page(pfn_to_phys(pte_pfn(*virt_to_kpte(kaddr))));
}
EXPORT_SYMBOL(tlb_virt_to_page);
--
2.43.0
On Thu, 4 Apr 2024 21:36:34 +0800 Huacai Chen <[email protected]> wrote:
> LoongArch will override page_to_virt() which use page_address() in the
> KFENCE case (by defining WANT_PAGE_VIRTUAL/HASHED_PAGE_VIRTUAL). So move
> lowmem_page_address() a little later to avoid such build errors:
>
> error: implicit declaration of function 'page_address'.
>
Acked-by: Andrew Morton <[email protected]>
Please ensure that it spends adequate time in linux-next for the
compilation testing.
On Fri, Apr 5, 2024 at 2:25 AM Andrew Morton <akpm@linux-foundationorg> wrote:
>
> On Thu, 4 Apr 2024 21:36:34 +0800 Huacai Chen <[email protected]> wrote:
>
> > LoongArch will override page_to_virt() which use page_address() in the
> > KFENCE case (by defining WANT_PAGE_VIRTUAL/HASHED_PAGE_VIRTUAL). So move
> > lowmem_page_address() a little later to avoid such build errors:
> >
> > error: implicit declaration of function 'page_address'.
> >
>
> Acked-by: Andrew Morton <[email protected]>
>
> Please ensure that it spends adequate time in linux-next for the
> compilation testing.
OK, thanks.
Huacai