Re: [PATCH 01/11] Initialize the mapping of KASan shadow memory

From: Liuwenliang (Abbott Liu)
Date: Wed Nov 22 2017 - 08:00:11 EST


On Nov 22, 2017 20:30 Mark Rutland [mailto:mark.rutland@xxxxxxx] wrote:
>On Tue, Nov 21, 2017 at 07:59:01AM +0000, Liuwenliang (Abbott Liu) wrote:
>> On Nov 17, 2017 21:49 Marc Zyngier [mailto:marc.zyngier@xxxxxxx] wrote:
>> >On Sat, 18 Nov 2017 10:40:08 +0000
>> >"Liuwenliang (Abbott Liu)" <liuwenliang@xxxxxxxxxx> wrote:
>> >> On Nov 17, 2017 15:36 Christoffer Dall [mailto:cdall@xxxxxxxxxx] wrote:

>> Please don't ask people to limit to 4GB of physical space on CPU
>> supporting LPAE, please don't ask people to guaranteed to have some
>> memory below 4GB on CPU supporting LPAE.

>I don't think that Marc is suggesting that you'd always use the 32-bit
>accessors on an LPAE system, just that all the definitions should exist
>regardless of configuration.

>So rather than this:

>> +#ifdef CONFIG_ARM_LPAE
>> +#define TTBR0 __ACCESS_CP15_64(0, c2)
>> +#define TTBR1 __ACCESS_CP15_64(1, c2)
>> +#define PAR __ACCESS_CP15_64(0, c7)
>> +#else
>> +#define TTBR0 __ACCESS_CP15(c2, 0, c0, 0)
>> +#define TTBR1 __ACCESS_CP15(c2, 0, c0, 1)
>> +#define PAR __ACCESS_CP15(c7, 0, c4, 0)
>> +#endif

>... you'd have the following in cp15.h:

>#define TTBR0_64 __ACCESS_CP15_64(0, c2)
>#define TTBR1_64 __ACCESS_CP15_64(1, c2)
>#define PAR_64 __ACCESS_CP15_64(0, c7)

>#define TTBR0_32 __ACCESS_CP15(c2, 0, c0, 0)
>#define TTBR1_32 __ACCESS_CP15(c2, 0, c0, 1)
>#define PAR_32 __ACCESS_CP15(c7, 0, c4, 0)

>... and elsewhere, where it matters, we choose which to use depending on
>the kernel configuration, e.g.

>void set_ttbr0(u64 val)
>{
> if (IS_ENABLED(CONFIG_ARM_LPAE))
> write_sysreg(val, TTBR0_64);
> else
> write_sysreg(val, TTBR0_32);
>}

>Thanks,
>Mark.

Thanks for your solution.
I didn't know there was a IS_ENABLED macro that I can use, so I can't write a function
like:
void set_ttbr0(u64 val)
{
if (IS_ENABLED(CONFIG_ARM_LPAE))
write_sysreg(val, TTBR0_64);
else
write_sysreg(val, TTBR0_32);
}


Here is the code I tested on vexpress_a9 and vexpress_a15:
diff --git a/arch/arm/include/asm/cp15.h b/arch/arm/include/asm/cp15.h
index dbdbce1..5eb0185 100644
--- a/arch/arm/include/asm/cp15.h
+++ b/arch/arm/include/asm/cp15.h
@@ -2,6 +2,7 @@
#define __ASM_ARM_CP15_H

#include <asm/barrier.h>
+#include <linux/stringify.h>

/*
* CR1 bits (CP#15 CR1)
@@ -64,8 +65,93 @@
#define __write_sysreg(v, r, w, c, t) asm volatile(w " " c : : "r" ((t)(v)))
#define write_sysreg(v, ...) __write_sysreg(v, __VA_ARGS__)

+#define TTBR0_32 __ACCESS_CP15(c2, 0, c0, 0)
+#define TTBR1_32 __ACCESS_CP15(c2, 0, c0, 1)
+#define TTBR0_64 __ACCESS_CP15_64(0, c2)
+#define TTBR1_64 __ACCESS_CP15_64(1, c2)
+#define PAR __ACCESS_CP15_64(0, c7)
+#define VTTBR __ACCESS_CP15_64(6, c2)
+#define CNTV_CVAL __ACCESS_CP15_64(3, c14)
+#define CNTVOFF __ACCESS_CP15_64(4, c14)
+
+#define MIDR __ACCESS_CP15(c0, 0, c0, 0)
+#define CSSELR __ACCESS_CP15(c0, 2, c0, 0)
+#define VPIDR __ACCESS_CP15(c0, 4, c0, 0)
+#define VMPIDR __ACCESS_CP15(c0, 4, c0, 5)
+#define SCTLR __ACCESS_CP15(c1, 0, c0, 0)
+#define CPACR __ACCESS_CP15(c1, 0, c0, 2)
+#define HCR __ACCESS_CP15(c1, 4, c1, 0)
+#define HDCR __ACCESS_CP15(c1, 4, c1, 1)
+#define HCPTR __ACCESS_CP15(c1, 4, c1, 2)
+#define HSTR __ACCESS_CP15(c1, 4, c1, 3)
+#define TTBCR __ACCESS_CP15(c2, 0, c0, 2)
+#define HTCR __ACCESS_CP15(c2, 4, c0, 2)
+#define VTCR __ACCESS_CP15(c2, 4, c1, 2)
+#define DACR __ACCESS_CP15(c3, 0, c0, 0)
+#define DFSR __ACCESS_CP15(c5, 0, c0, 0)
+#define IFSR __ACCESS_CP15(c5, 0, c0, 1)
+#define ADFSR __ACCESS_CP15(c5, 0, c1, 0)
+#define AIFSR __ACCESS_CP15(c5, 0, c1, 1)
+#define HSR __ACCESS_CP15(c5, 4, c2, 0)
+#define DFAR __ACCESS_CP15(c6, 0, c0, 0)
+#define IFAR __ACCESS_CP15(c6, 0, c0, 2)
+#define HDFAR __ACCESS_CP15(c6, 4, c0, 0)
+#define HIFAR __ACCESS_CP15(c6, 4, c0, 2)
+#define HPFAR __ACCESS_CP15(c6, 4, c0, 4)
+#define ICIALLUIS __ACCESS_CP15(c7, 0, c1, 0)
+#define ATS1CPR __ACCESS_CP15(c7, 0, c8, 0)
+#define TLBIALLIS __ACCESS_CP15(c8, 0, c3, 0)
+#define TLBIALL __ACCESS_CP15(c8, 0, c7, 0)
+#define TLBIALLNSNHIS __ACCESS_CP15(c8, 4, c3, 4)
+#define PRRR __ACCESS_CP15(c10, 0, c2, 0)
+#define NMRR __ACCESS_CP15(c10, 0, c2, 1)
+#define AMAIR0 __ACCESS_CP15(c10, 0, c3, 0)
+#define AMAIR1 __ACCESS_CP15(c10, 0, c3, 1)
+#define VBAR __ACCESS_CP15(c12, 0, c0, 0)
+#define CID __ACCESS_CP15(c13, 0, c0, 1)
+#define TID_URW __ACCESS_CP15(c13, 0, c0, 2)
+#define TID_URO __ACCESS_CP15(c13, 0, c0, 3)
+#define TID_PRIV __ACCESS_CP15(c13, 0, c0, 4)
+#define HTPIDR __ACCESS_CP15(c13, 4, c0, 2)
+#define CNTKCTL __ACCESS_CP15(c14, 0, c1, 0)
+#define CNTV_CTL __ACCESS_CP15(c14, 0, c3, 1)
+#define CNTHCTL __ACCESS_CP15(c14, 4, c1, 0)
+
extern unsigned long cr_alignment; /* defined in entry-armv.S */

+
+static inline void set_ttbr0(u64 val)
+{
+ if (IS_ENABLED(CONFIG_ARM_LPAE))
+ write_sysreg(val, TTBR0_64);
+ else
+ write_sysreg(val, TTBR0_32);
+}
+
+static inline u64 get_ttbr0(void)
+{
+ if (IS_ENABLED(CONFIG_ARM_LPAE))
+ return read_sysreg(TTBR0_64);
+ else
+ return (u64)read_sysreg(TTBR0_32);
+}
+
+static inline void set_ttbr1(u64 val)
+{
+ if (IS_ENABLED(CONFIG_ARM_LPAE))
+ write_sysreg(val, TTBR1_64);
+ else
+ write_sysreg(val, TTBR1_32);
+}
+
+static inline u64 get_ttbr1(void)
+{
+ if (IS_ENABLED(CONFIG_ARM_LPAE))
+ return read_sysreg(TTBR1_64);
+ else
+ return (u64)read_sysreg(TTBR1_32);
+}
+
static inline unsigned long get_cr(void)
{
unsigned long val;
diff --git a/arch/arm/include/asm/kvm_hyp.h b/arch/arm/include/asm/kvm_hyp.h
index 14b5903..8db8a8c 100644
--- a/arch/arm/include/asm/kvm_hyp.h
+++ b/arch/arm/include/asm/kvm_hyp.h
@@ -37,56 +37,6 @@
__val; \
})

-#define TTBR0 __ACCESS_CP15_64(0, c2)
-#define TTBR1 __ACCESS_CP15_64(1, c2)
-#define VTTBR __ACCESS_CP15_64(6, c2)
-#define PAR __ACCESS_CP15_64(0, c7)
-#define CNTV_CVAL __ACCESS_CP15_64(3, c14)
-#define CNTVOFF __ACCESS_CP15_64(4, c14)
-
-#define MIDR __ACCESS_CP15(c0, 0, c0, 0)
-#define CSSELR __ACCESS_CP15(c0, 2, c0, 0)
-#define VPIDR __ACCESS_CP15(c0, 4, c0, 0)
-#define VMPIDR __ACCESS_CP15(c0, 4, c0, 5)
-#define SCTLR __ACCESS_CP15(c1, 0, c0, 0)
-#define CPACR __ACCESS_CP15(c1, 0, c0, 2)
-#define HCR __ACCESS_CP15(c1, 4, c1, 0)
-#define HDCR __ACCESS_CP15(c1, 4, c1, 1)
-#define HCPTR __ACCESS_CP15(c1, 4, c1, 2)
-#define HSTR __ACCESS_CP15(c1, 4, c1, 3)
-#define TTBCR __ACCESS_CP15(c2, 0, c0, 2)
-#define HTCR __ACCESS_CP15(c2, 4, c0, 2)
-#define VTCR __ACCESS_CP15(c2, 4, c1, 2)
-#define DACR __ACCESS_CP15(c3, 0, c0, 0)
-#define DFSR __ACCESS_CP15(c5, 0, c0, 0)
-#define IFSR __ACCESS_CP15(c5, 0, c0, 1)
-#define ADFSR __ACCESS_CP15(c5, 0, c1, 0)
-#define AIFSR __ACCESS_CP15(c5, 0, c1, 1)
-#define HSR __ACCESS_CP15(c5, 4, c2, 0)
-#define DFAR __ACCESS_CP15(c6, 0, c0, 0)
-#define IFAR __ACCESS_CP15(c6, 0, c0, 2)
-#define HDFAR __ACCESS_CP15(c6, 4, c0, 0)
-#define HIFAR __ACCESS_CP15(c6, 4, c0, 2)
-#define HPFAR __ACCESS_CP15(c6, 4, c0, 4)
-#define ICIALLUIS __ACCESS_CP15(c7, 0, c1, 0)
-#define ATS1CPR __ACCESS_CP15(c7, 0, c8, 0)
-#define TLBIALLIS __ACCESS_CP15(c8, 0, c3, 0)
-#define TLBIALL __ACCESS_CP15(c8, 0, c7, 0)
-#define TLBIALLNSNHIS __ACCESS_CP15(c8, 4, c3, 4)
-#define PRRR __ACCESS_CP15(c10, 0, c2, 0)
-#define NMRR __ACCESS_CP15(c10, 0, c2, 1)
-#define AMAIR0 __ACCESS_CP15(c10, 0, c3, 0)
-#define AMAIR1 __ACCESS_CP15(c10, 0, c3, 1)
-#define VBAR __ACCESS_CP15(c12, 0, c0, 0)
-#define CID __ACCESS_CP15(c13, 0, c0, 1)
-#define TID_URW __ACCESS_CP15(c13, 0, c0, 2)
-#define TID_URO __ACCESS_CP15(c13, 0, c0, 3)
-#define TID_PRIV __ACCESS_CP15(c13, 0, c0, 4)
-#define HTPIDR __ACCESS_CP15(c13, 4, c0, 2)
-#define CNTKCTL __ACCESS_CP15(c14, 0, c1, 0)
-#define CNTV_CTL __ACCESS_CP15(c14, 0, c3, 1)
-#define CNTHCTL __ACCESS_CP15(c14, 4, c1, 0)
-
#define VFP_FPEXC __ACCESS_VFP(FPEXC)

/* AArch64 compatibility macros, only for the timer so far */
diff --git a/arch/arm/kvm/hyp/cp15-sr.c b/arch/arm/kvm/hyp/cp15-sr.c
index c478281..d1302ae 100644
--- a/arch/arm/kvm/hyp/cp15-sr.c
+++ b/arch/arm/kvm/hyp/cp15-sr.c
@@ -31,8 +31,8 @@ void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
ctxt->cp15[c0_CSSELR] = read_sysreg(CSSELR);
ctxt->cp15[c1_SCTLR] = read_sysreg(SCTLR);
ctxt->cp15[c1_CPACR] = read_sysreg(CPACR);
- *cp15_64(ctxt, c2_TTBR0) = read_sysreg(TTBR0);
- *cp15_64(ctxt, c2_TTBR1) = read_sysreg(TTBR1);
+ *cp15_64(ctxt, c2_TTBR0) = read_sysreg(TTBR0_64);
+ *cp15_64(ctxt, c2_TTBR1) = read_sysreg(TTBR1_64);
ctxt->cp15[c2_TTBCR] = read_sysreg(TTBCR);
ctxt->cp15[c3_DACR] = read_sysreg(DACR);
ctxt->cp15[c5_DFSR] = read_sysreg(DFSR);
@@ -60,8 +60,8 @@ void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
write_sysreg(ctxt->cp15[c0_CSSELR], CSSELR);
write_sysreg(ctxt->cp15[c1_SCTLR], SCTLR);
write_sysreg(ctxt->cp15[c1_CPACR], CPACR);
- write_sysreg(*cp15_64(ctxt, c2_TTBR0), TTBR0);
- write_sysreg(*cp15_64(ctxt, c2_TTBR1), TTBR1);
+ write_sysreg(*cp15_64(ctxt, c2_TTBR0), TTBR0_64);
+ write_sysreg(*cp15_64(ctxt, c2_TTBR1), TTBR1_64);
write_sysreg(ctxt->cp15[c2_TTBCR], TTBCR);
write_sysreg(ctxt->cp15[c3_DACR], DACR);
write_sysreg(ctxt->cp15[c5_DFSR], DFSR);
diff --git a/arch/arm/mm/kasan_init.c b/arch/arm/mm/kasan_init.c
index 049ee0a..87c86c7 100644
--- a/arch/arm/mm/kasan_init.c
+++ b/arch/arm/mm/kasan_init.c
@@ -203,16 +203,16 @@ void __init kasan_init(void)
u64 orig_ttbr0;
int i;

- orig_ttbr0 = cpu_get_ttbr(0);
+ orig_ttbr0 = get_ttbr0();

#ifdef CONFIG_ARM_LPAE
memcpy(tmp_pmd_table, pgd_page_vaddr(*pgd_offset_k(KASAN_SHADOW_START)), sizeof(tmp_pmd_table));
memcpy(tmp_page_table, swapper_pg_dir, sizeof(tmp_page_table));
set_pgd(&tmp_page_table[pgd_index(KASAN_SHADOW_START)], __pgd(__pa(tmp_pmd_table) | PMD_TYPE_TABLE | L_PGD_SWAPPER));
- cpu_set_ttbr0(__pa(tmp_page_table));
+ set_ttbr0(__pa(tmp_page_table));
#else
memcpy(tmp_page_table, swapper_pg_dir, sizeof(tmp_page_table));
- cpu_set_ttbr0(__pa(tmp_page_table));
+ set_ttbr0((u64)__pa(tmp_page_table));
#endif
flush_cache_all();
local_flush_bp_all();
@@ -257,7 +257,7 @@ void __init kasan_init(void)
/*__pgprot(_L_PTE_DEFAULT | L_PTE_DIRTY | L_PTE_XN | L_PTE_RDONLY))*/
__pgprot(pgprot_val(PAGE_KERNEL) | L_PTE_RDONLY)));
memset(kasan_zero_page, 0, PAGE_SIZE);
- cpu_set_ttbr0(orig_ttbr0);
+ set_ttbr0(orig_ttbr0);
flush_cache_all();
local_flush_bp_all();
local_flush_tlb_all();