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

From: Liuwenliang (Abbott Liu)
Date: Wed Nov 22 2017 - 20:56:55 EST


On Nov 23, 2017 20:30 Marc Zyngier [mailto:marc.zyngier@xxxxxxx] wrote:
>Please define both PAR accessors. Yes, I know the 32bit version is not
>used yet, but it doesn't hurt to make it visible.

Thanks for your review.
I'm going to change it in the new version.
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..b8353b1 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 +65,109 @@
#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 PAR_32 __ACCESS_CP15(c7, 0, c4, 0)
+#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 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_par(u64 val)
+{
+ if (IS_ENABLED(CONFIG_ARM_LPAE))
+ write_sysreg(val, PAR_64);
+ else
+ write_sysreg(val, PAR_32);
+}
+
+static inline u64 get_par(void)
+{
+ if (IS_ENABLED(CONFIG_ARM_LPAE))
+ return read_sysreg(PAR_64);
+ else
+ return (u64)read_sysreg(PAR_32);
+}
+
+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..d365e3c 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);
@@ -41,7 +41,7 @@ void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
ctxt->cp15[c5_AIFSR] = read_sysreg(AIFSR);
ctxt->cp15[c6_DFAR] = read_sysreg(DFAR);
ctxt->cp15[c6_IFAR] = read_sysreg(IFAR);
- *cp15_64(ctxt, c7_PAR) = read_sysreg(PAR);
+ *cp15_64(ctxt, c7_PAR) = read_sysreg(PAR_64);
ctxt->cp15[c10_PRRR] = read_sysreg(PRRR);
ctxt->cp15[c10_NMRR] = read_sysreg(NMRR);
ctxt->cp15[c10_AMAIR0] = read_sysreg(AMAIR0);
@@ -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);
@@ -70,7 +70,7 @@ void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
write_sysreg(ctxt->cp15[c5_AIFSR], AIFSR);
write_sysreg(ctxt->cp15[c6_DFAR], DFAR);
write_sysreg(ctxt->cp15[c6_IFAR], IFAR);
- write_sysreg(*cp15_64(ctxt, c7_PAR), PAR);
+ write_sysreg(*cp15_64(ctxt, c7_PAR), PAR_64);
write_sysreg(ctxt->cp15[c10_PRRR], PRRR);
write_sysreg(ctxt->cp15[c10_NMRR], NMRR);
write_sysreg(ctxt->cp15[c10_AMAIR0], AMAIR0);
diff --git a/arch/arm/kvm/hyp/switch.c b/arch/arm/kvm/hyp/switch.c
index ebd2dd4..4879588 100644
--- a/arch/arm/kvm/hyp/switch.c
+++ b/arch/arm/kvm/hyp/switch.c
@@ -133,12 +133,12 @@ static bool __hyp_text __populate_fault_info(struct kvm_vcpu *vcpu)
if (!(hsr & HSR_DABT_S1PTW) && (hsr & HSR_FSC_TYPE) == FSC_PERM) {
u64 par, tmp;

- par = read_sysreg(PAR);
+ par = read_sysreg(PAR_64);
write_sysreg(far, ATS1CPR);
isb();

- tmp = read_sysreg(PAR);
- write_sysreg(par, PAR);
+ tmp = read_sysreg(PAR_64);
+ write_sysreg(par, PAR_64);

if (unlikely(tmp & 1))
return false; /* Translation failed, back to guest */
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();



-----éäåä-----
åää: Marc Zyngier [mailto:marc.zyngier@xxxxxxx]
åéæé: 2017å11æ22æ 21:06
æää: Liuwenliang (Abbott Liu); Mark Rutland
æé: tixy@xxxxxxxxxx; mhocko@xxxxxxxx; grygorii.strashko@xxxxxxxxxx; catalin.marinas@xxxxxxx; linux-mm@xxxxxxxxx; glider@xxxxxxxxxx; afzal.mohd.ma@xxxxxxxxx; mingo@xxxxxxxxxx; Christoffer Dall; f.fainelli@xxxxxxxxx; mawilcox@xxxxxxxxxxxxx; linux@xxxxxxxxxxxxxxx; kasan-dev@xxxxxxxxxxxxxxxx; Dailei; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; aryabinin@xxxxxxxxxxxxx; labbott@xxxxxxxxxx; vladimir.murzin@xxxxxxx; keescook@xxxxxxxxxxxx; arnd@xxxxxxxx; Zengweilin; opendmb@xxxxxxxxx; Heshaoliang; tglx@xxxxxxxxxxxxx; dvyukov@xxxxxxxxxx; ard.biesheuvel@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Jiazhenghua; akpm@xxxxxxxxxxxxxxxxxxxx; robin.murphy@xxxxxxx; thgarnie@xxxxxxxxxx; kirill.shutemov@xxxxxxxxxxxxxxx
äé: Re: [PATCH 01/11] Initialize the mapping of KASan shadow memory

On 22/11/17 12:56, Liuwenliang (Abbott Liu) wrote:
> 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)

Please define both PAR accessors. Yes, I know the 32bit version is not
used yet, but it doesn't hurt to make it visible.

Thanks,

M.
--
Jazz is not dead. It just smells funny...