This patchset is support KASAN_VMALLOC in riscv.
We reference x86/s390 mailing list discussion for our implement.
https://lwn.net/Articles/797950/
It's also pass `vmalloc-out-of-bounds` of test_kasan.ko
log:
[ 235.834318] # Subtest: kasan
[ 235.835190] 1..37
[ 235.845238]
==================================================================
[ 235.847818] BUG: KASAN: slab-out-of-bounds in
kmalloc_oob_right+0xe2/0x192 [test_kasan]
[ 235.850688] Write of size 1 at addr ffffffe0075d5a7b by task
kunit_try_catch/125
[ 235.852630]
[ 235.853212] CPU: 0 PID: 125 Comm: kunit_try_catch Tainted: G B
5.11.0-rc3-13940-gb0bb4cd86282-dirty #1
...
[ 241.835850]
==================================================================
[1154/67143]
[ 241.840884] ok 36 - kmalloc_double_kzfree
[ 241.852642]
==================================================================
[ 241.857261] BUG: KASAN: vmalloc-out-of-bounds in
vmalloc_oob+0xcc/0x17c [test_kasan]
[ 241.861327] Read of size 1 at addr ffffffd00407ec1c by task
kunit_try_catch/161
[ 241.864525]
[ 241.865200] CPU: 0 PID: 161 Comm: kunit_try_catch Tainted: G B
5.11.0-rc3-13940-gb0bb4cd86282-dirty #1
[ 241.869887] Call Trace:
[ 241.870972] [<ffffffe0000052d2>] walk_stackframe+0x0/0x128
[ 241.873353] [<ffffffe000abcff0>] show_stack+0x32/0x3e
[ 241.875457] [<ffffffe000ac0d46>] dump_stack+0x84/0xa0
[ 241.877806] [<ffffffe000188926>]
print_address_description.constprop.0+0x88/0x362
[ 241.881150] [<ffffffe000188e4a>] kasan_report+0x176/0x194
[ 241.883604] [<ffffffe000189390>] __asan_load1+0x42/0x4a
[ 241.885897] [<ffffffdf81f9f2f4>] vmalloc_oob+0xcc/0x17c [test_kasan]
[ 241.889458] [<ffffffdf81f91e8e>] kunit_try_run_case+0x80/0x11a
[kunit]
[ 241.892665] [<ffffffdf81f92e16>]
kunit_generic_run_threadfn_adapter+0x2c/0x4e [kunit]
[ 241.896568] [<ffffffe000034ac4>] kthread+0x206/0x222
[ 241.899219] [<ffffffe00000361a>] ret_from_exception+0x0/0xc
[ 241.901700]
[ 241.902497]
[ 241.903257] Memory state around the buggy address:
[ 241.905430] ffffffd00407eb00: 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00
[ 241.908661] ffffffd00407eb80: 00 00 00 00 00 00 00 f8 f8 f8 f8 f8 f8
f8 f8 f8
[ 241.911841] >ffffffd00407ec00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
f8 f8 f8
[ 241.915037] ^
[ 241.916053] ffffffd00407ec80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
f8 f8 f8
[ 241.919272] ffffffd00407ed00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
f8 f8 f8
[ 241.922417]
==================================================================
[ 242.073698] ok 37 - vmalloc_oob
Nylon Chen (1):
riscv/kasan: add KASAN_VMALLOC support
arch/riscv/Kconfig | 1 +
arch/riscv/mm/kasan_init.c | 66 +++++++++++++++++++++++++++++++++++++-
2 files changed, 66 insertions(+), 1 deletion(-)
--
2.17.1
It's reference x86/s390 architecture.
So, it's don't map the early shadow page to cover VMALLOC space.
Prepopulate top level page table for the range that would otherwise be
empty.
lower levels are filled dynamically upon memory allocation while
booting.
Signed-off-by: Nylon Chen <[email protected]>
Signed-off-by: Nick Hu <[email protected]>
---
arch/riscv/Kconfig | 1 +
arch/riscv/mm/kasan_init.c | 66 +++++++++++++++++++++++++++++++++++++-
2 files changed, 66 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 81b76d44725d..15a2c8088bbe 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -57,6 +57,7 @@ config RISCV
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_JUMP_LABEL_RELATIVE
select HAVE_ARCH_KASAN if MMU && 64BIT
+ select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
select HAVE_ARCH_KGDB
select HAVE_ARCH_KGDB_QXFER_PKT
select HAVE_ARCH_MMAP_RND_BITS if MMU
diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
index 12ddd1f6bf70..ee332513d728 100644
--- a/arch/riscv/mm/kasan_init.c
+++ b/arch/riscv/mm/kasan_init.c
@@ -9,6 +9,19 @@
#include <linux/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/fixmap.h>
+#include <asm/pgalloc.h>
+
+static __init void *early_alloc(size_t size, int node)
+{
+ void *ptr = memblock_alloc_try_nid(size, size,
+ __pa(MAX_DMA_ADDRESS), MEMBLOCK_ALLOC_ACCESSIBLE, node);
+
+ if (!ptr)
+ panic("%pS: Failed to allocate %zu bytes align=%zx nid=%d from=%llx\n",
+ __func__, size, size, node, (u64)__pa(MAX_DMA_ADDRESS));
+
+ return ptr;
+}
extern pgd_t early_pg_dir[PTRS_PER_PGD];
asmlinkage void __init kasan_early_init(void)
@@ -83,6 +96,49 @@ static void __init populate(void *start, void *end)
memset(start, 0, end - start);
}
+void __init kasan_shallow_populate(void *start, void *end)
+{
+ unsigned long vaddr = (unsigned long)start & PAGE_MASK;
+ unsigned long vend = PAGE_ALIGN((unsigned long)end);
+ unsigned long pfn;
+ int index;
+ void *p;
+ pud_t *pud_dir, *pud_k;
+ pmd_t *pmd_dir, *pmd_k;
+ pgd_t *pgd_dir, *pgd_k;
+ p4d_t *p4d_dir, *p4d_k;
+
+ while (vaddr < vend) {
+ index = pgd_index(vaddr);
+ pfn = csr_read(CSR_SATP) & SATP_PPN;
+ pgd_dir = (pgd_t *)pfn_to_virt(pfn) + index;
+ pgd_k = init_mm.pgd + index;
+ pgd_dir = pgd_offset_k(vaddr);
+ set_pgd(pgd_dir, *pgd_k);
+
+ p4d_dir = p4d_offset(pgd_dir, vaddr);
+ p4d_k = p4d_offset(pgd_k,vaddr);
+
+ vaddr = (vaddr + PUD_SIZE) & PUD_MASK;
+ pud_dir = pud_offset(p4d_dir, vaddr);
+ pud_k = pud_offset(p4d_k,vaddr);
+
+ if (pud_present(*pud_dir)) {
+ p = early_alloc(PAGE_SIZE, NUMA_NO_NODE);
+ pud_populate(&init_mm, pud_dir, p);
+ }
+
+ pmd_dir = pmd_offset(pud_dir, vaddr);
+ pmd_k = pmd_offset(pud_k,vaddr);
+ set_pmd(pmd_dir, *pmd_k);
+ if (pmd_present(*pmd_dir)) {
+ p = early_alloc(PAGE_SIZE, NUMA_NO_NODE);
+ pmd_populate(&init_mm, pmd_dir, p);
+ }
+ vaddr += PAGE_SIZE;
+ }
+}
+
void __init kasan_init(void)
{
phys_addr_t _start, _end;
@@ -90,7 +146,15 @@ void __init kasan_init(void)
kasan_populate_early_shadow((void *)KASAN_SHADOW_START,
(void *)kasan_mem_to_shadow((void *)
- VMALLOC_END));
+ VMEMMAP_END));
+ if (IS_ENABLED(CONFIG_KASAN_VMALLOC))
+ kasan_shallow_populate(
+ (void *)kasan_mem_to_shadow((void *)VMALLOC_START),
+ (void *)kasan_mem_to_shadow((void *)VMALLOC_END));
+ else
+ kasan_populate_early_shadow(
+ (void *)kasan_mem_to_shadow((void *)VMALLOC_START),
+ (void *)kasan_mem_to_shadow((void *)VMALLOC_END));
for_each_mem_range(i, &_start, &_end) {
void *start = (void *)_start;
--
2.17.1
On Tue, 12 Jan 2021 18:28:22 PST (-0800), [email protected] wrote:
> It's reference x86/s390 architecture.
>
> So, it's don't map the early shadow page to cover VMALLOC space.
>
> Prepopulate top level page table for the range that would otherwise be
> empty.
>
> lower levels are filled dynamically upon memory allocation while
> booting.
>
> Signed-off-by: Nylon Chen <[email protected]>
> Signed-off-by: Nick Hu <[email protected]>
> ---
> arch/riscv/Kconfig | 1 +
> arch/riscv/mm/kasan_init.c | 66 +++++++++++++++++++++++++++++++++++++-
> 2 files changed, 66 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 81b76d44725d..15a2c8088bbe 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -57,6 +57,7 @@ config RISCV
> select HAVE_ARCH_JUMP_LABEL
> select HAVE_ARCH_JUMP_LABEL_RELATIVE
> select HAVE_ARCH_KASAN if MMU && 64BIT
> + select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
> select HAVE_ARCH_KGDB
> select HAVE_ARCH_KGDB_QXFER_PKT
> select HAVE_ARCH_MMAP_RND_BITS if MMU
> diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
> index 12ddd1f6bf70..ee332513d728 100644
> --- a/arch/riscv/mm/kasan_init.c
> +++ b/arch/riscv/mm/kasan_init.c
> @@ -9,6 +9,19 @@
> #include <linux/pgtable.h>
> #include <asm/tlbflush.h>
> #include <asm/fixmap.h>
> +#include <asm/pgalloc.h>
> +
> +static __init void *early_alloc(size_t size, int node)
> +{
> + void *ptr = memblock_alloc_try_nid(size, size,
> + __pa(MAX_DMA_ADDRESS), MEMBLOCK_ALLOC_ACCESSIBLE, node);
> +
> + if (!ptr)
> + panic("%pS: Failed to allocate %zu bytes align=%zx nid=%d from=%llx\n",
> + __func__, size, size, node, (u64)__pa(MAX_DMA_ADDRESS));
> +
> + return ptr;
> +}
>
> extern pgd_t early_pg_dir[PTRS_PER_PGD];
> asmlinkage void __init kasan_early_init(void)
> @@ -83,6 +96,49 @@ static void __init populate(void *start, void *end)
> memset(start, 0, end - start);
> }
>
> +void __init kasan_shallow_populate(void *start, void *end)
> +{
> + unsigned long vaddr = (unsigned long)start & PAGE_MASK;
> + unsigned long vend = PAGE_ALIGN((unsigned long)end);
> + unsigned long pfn;
> + int index;
> + void *p;
> + pud_t *pud_dir, *pud_k;
> + pmd_t *pmd_dir, *pmd_k;
> + pgd_t *pgd_dir, *pgd_k;
> + p4d_t *p4d_dir, *p4d_k;
> +
> + while (vaddr < vend) {
> + index = pgd_index(vaddr);
> + pfn = csr_read(CSR_SATP) & SATP_PPN;
> + pgd_dir = (pgd_t *)pfn_to_virt(pfn) + index;
> + pgd_k = init_mm.pgd + index;
> + pgd_dir = pgd_offset_k(vaddr);
> + set_pgd(pgd_dir, *pgd_k);
> +
> + p4d_dir = p4d_offset(pgd_dir, vaddr);
> + p4d_k = p4d_offset(pgd_k,vaddr);
> +
> + vaddr = (vaddr + PUD_SIZE) & PUD_MASK;
> + pud_dir = pud_offset(p4d_dir, vaddr);
> + pud_k = pud_offset(p4d_k,vaddr);
> +
> + if (pud_present(*pud_dir)) {
> + p = early_alloc(PAGE_SIZE, NUMA_NO_NODE);
> + pud_populate(&init_mm, pud_dir, p);
> + }
> +
> + pmd_dir = pmd_offset(pud_dir, vaddr);
> + pmd_k = pmd_offset(pud_k,vaddr);
> + set_pmd(pmd_dir, *pmd_k);
> + if (pmd_present(*pmd_dir)) {
> + p = early_alloc(PAGE_SIZE, NUMA_NO_NODE);
> + pmd_populate(&init_mm, pmd_dir, p);
> + }
> + vaddr += PAGE_SIZE;
> + }
> +}
> +
> void __init kasan_init(void)
> {
> phys_addr_t _start, _end;
> @@ -90,7 +146,15 @@ void __init kasan_init(void)
>
> kasan_populate_early_shadow((void *)KASAN_SHADOW_START,
> (void *)kasan_mem_to_shadow((void *)
> - VMALLOC_END));
> + VMEMMAP_END));
> + if (IS_ENABLED(CONFIG_KASAN_VMALLOC))
> + kasan_shallow_populate(
> + (void *)kasan_mem_to_shadow((void *)VMALLOC_START),
> + (void *)kasan_mem_to_shadow((void *)VMALLOC_END));
> + else
> + kasan_populate_early_shadow(
> + (void *)kasan_mem_to_shadow((void *)VMALLOC_START),
> + (void *)kasan_mem_to_shadow((void *)VMALLOC_END));
>
> for_each_mem_range(i, &_start, &_end) {
> void *start = (void *)_start;
There are a bunch of checkpatch issues here.