Add infrastructure to display CPU vulnerabilities.
As most MIPS CPU vendors are dead today and we can't confirm
vulnerabilities states with them, we'll display vulnerabilities
as "Unknown" by default and override them in cpu-probe.c
Signed-off-by: Jiaxun Yang <[email protected]>
---
arch/mips/Kconfig | 1 +
arch/mips/include/asm/cpu-info.h | 5 ++++
arch/mips/include/asm/cpu.h | 7 +++++
arch/mips/kernel/Makefile | 2 +-
arch/mips/kernel/vulnbl.c | 46 ++++++++++++++++++++++++++++++++
5 files changed, 60 insertions(+), 1 deletion(-)
create mode 100644 arch/mips/kernel/vulnbl.c
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index ef5b2a177b1b..524053b8f769 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -24,6 +24,7 @@ config MIPS
select GENERIC_CLOCKEVENTS
select GENERIC_CMOS_UPDATE
select GENERIC_CPU_AUTOPROBE
+ select GENERIC_CPU_VULNERABILITIES
select GENERIC_GETTIMEOFDAY
select GENERIC_IOMAP
select GENERIC_IRQ_PROBE
diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h
index a600670d00e9..1a964dbfc0a8 100644
--- a/arch/mips/include/asm/cpu-info.h
+++ b/arch/mips/include/asm/cpu-info.h
@@ -106,6 +106,11 @@ struct cpuinfo_mips {
unsigned int guestid_mask;
unsigned int guestid_cache;
+ /* Vulnerabilities */
+ unsigned int vulnerabilities; /* Vulnerabilities states that we known */
+ unsigned int vulnerable; /* Vulnerabilities affated */
+ unsigned int mitigations; /* Mitigations */
+
#ifdef CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION
/* CPUCFG data for this CPU, synthesized at probe time.
*
diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index f5b04e8f6061..3414c9f5464e 100644
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -447,4 +447,11 @@ enum cpu_type_enum {
#define MIPS_ASE_LOONGSON_EXT 0x00002000 /* Loongson EXTensions */
#define MIPS_ASE_LOONGSON_EXT2 0x00004000 /* Loongson EXTensions R2 */
+/*
+ * CPU security vulnerabilities
+ */
+#define MIPS_VULNBL_MELTDOWN BIT(0)
+#define MIPS_VULNBL_SPECTRE_V1 BIT(1)
+#define MIPS_VULNBL_SPECTRE_V2 BIT(2)
+
#endif /* _ASM_CPU_H */
diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index 13a26d254829..39abc8ead5e0 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -8,7 +8,7 @@ extra-y := head.o vmlinux.lds
obj-y += cmpxchg.o cpu-probe.o branch.o elf.o entry.o genex.o idle.o irq.o \
process.o prom.o ptrace.o reset.o setup.o signal.o \
syscall.o time.o topology.o traps.o unaligned.o watch.o \
- vdso.o cacheinfo.o
+ vdso.o cacheinfo.o vulnbl.o
ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_ftrace.o = -pg
diff --git a/arch/mips/kernel/vulnbl.c b/arch/mips/kernel/vulnbl.c
new file mode 100644
index 000000000000..fc73da6214fe
--- /dev/null
+++ b/arch/mips/kernel/vulnbl.c
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020, Jiaxun Yang <[email protected]>
+ * MIPS CPU vulnerabilities
+ */
+
+#include <linux/device.h>
+
+#include <asm/cpu-info.h>
+#include <asm/cpu.h>
+
+ssize_t cpu_show_meltdown(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ if (!(boot_cpu_data.vulnerabilities & MIPS_VULNBL_MELTDOWN))
+ return sprintf(buf, "Unknown\n");
+
+ if (!(boot_cpu_data.vulnerable & MIPS_VULNBL_MELTDOWN))
+ return sprintf(buf, "Not affected\n");
+
+ return sprintf(buf, "Affected\n");
+}
+
+ssize_t cpu_show_spectre_v1(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ if (!(boot_cpu_data.vulnerabilities & MIPS_VULNBL_SPECTRE_V1))
+ return sprintf(buf, "Unknown\n");
+
+ if (!(boot_cpu_data.vulnerable & MIPS_VULNBL_SPECTRE_V1))
+ return sprintf(buf, "Not affected\n");
+
+ return sprintf(buf, "Affected\n");
+}
+
+ssize_t cpu_show_spectre_v2(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ if (!(boot_cpu_data.vulnerabilities & MIPS_VULNBL_SPECTRE_V2))
+ return sprintf(buf, "Unknown\n");
+
+ if (!(boot_cpu_data.vulnerable & MIPS_VULNBL_SPECTRE_V2))
+ return sprintf(buf, "Not affected\n");
+
+ return sprintf(buf, "Affected\n");
+}
--
2.30.0
Loongson64C is known to be vulnerable to meltdown according to
PoC from Rui Wang <[email protected]>.
Loongson64G defended these side-channel attack by silicon.
Signed-off-by: Jiaxun Yang <[email protected]>
---
arch/mips/kernel/cpu-probe.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 2460783dbdb1..24b21f51353c 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -2092,6 +2092,8 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
c->ases |= (MIPS_ASE_LOONGSON_MMI | MIPS_ASE_LOONGSON_CAM |
MIPS_ASE_LOONGSON_EXT | MIPS_ASE_LOONGSON_EXT2);
c->ases &= ~MIPS_ASE_VZ; /* VZ of Loongson-3A2000/3000 is incomplete */
+ c->vulnerabilities |= MIPS_VULNBL_MELTDOWN;
+ c->vulnerable |= MIPS_VULNBL_MELTDOWN;
break;
case PRID_IMP_LOONGSON_64G:
c->cputype = CPU_LOONGSON64;
@@ -2100,6 +2102,8 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
set_isa(c, MIPS_CPU_ISA_M64R2);
decode_cpucfg(c);
c->writecombine = _CACHE_UNCACHED_ACCELERATED;
+ c->vulnerabilities |= MIPS_VULNBL_MELTDOWN |
+ MIPS_VULNBL_SPECTRE_V1 | MIPS_VULNBL_SPECTRE_V2;
break;
default:
panic("Unknown Loongson Processor ID!");
--
2.30.0
Hi, Jiaxun,
On Wed, Dec 30, 2020 at 11:25 AM Jiaxun Yang <[email protected]> wrote:
>
> Add infrastructure to display CPU vulnerabilities.
> As most MIPS CPU vendors are dead today and we can't confirm
> vulnerabilities states with them, we'll display vulnerabilities
> as "Unknown" by default and override them in cpu-probe.c
>
> Signed-off-by: Jiaxun Yang <[email protected]>
> ---
> arch/mips/Kconfig | 1 +
> arch/mips/include/asm/cpu-info.h | 5 ++++
> arch/mips/include/asm/cpu.h | 7 +++++
> arch/mips/kernel/Makefile | 2 +-
> arch/mips/kernel/vulnbl.c | 46 ++++++++++++++++++++++++++++++++
> 5 files changed, 60 insertions(+), 1 deletion(-)
> create mode 100644 arch/mips/kernel/vulnbl.c
>
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index ef5b2a177b1b..524053b8f769 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -24,6 +24,7 @@ config MIPS
> select GENERIC_CLOCKEVENTS
> select GENERIC_CMOS_UPDATE
> select GENERIC_CPU_AUTOPROBE
> + select GENERIC_CPU_VULNERABILITIES
> select GENERIC_GETTIMEOFDAY
> select GENERIC_IOMAP
> select GENERIC_IRQ_PROBE
> diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h
> index a600670d00e9..1a964dbfc0a8 100644
> --- a/arch/mips/include/asm/cpu-info.h
> +++ b/arch/mips/include/asm/cpu-info.h
> @@ -106,6 +106,11 @@ struct cpuinfo_mips {
> unsigned int guestid_mask;
> unsigned int guestid_cache;
>
> + /* Vulnerabilities */
> + unsigned int vulnerabilities; /* Vulnerabilities states that we known */
> + unsigned int vulnerable; /* Vulnerabilities affated */
What is "affated"? maybe "affected"?
Huacai
> + unsigned int mitigations; /* Mitigations */
> +
> #ifdef CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION
> /* CPUCFG data for this CPU, synthesized at probe time.
> *
> diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
> index f5b04e8f6061..3414c9f5464e 100644
> --- a/arch/mips/include/asm/cpu.h
> +++ b/arch/mips/include/asm/cpu.h
> @@ -447,4 +447,11 @@ enum cpu_type_enum {
> #define MIPS_ASE_LOONGSON_EXT 0x00002000 /* Loongson EXTensions */
> #define MIPS_ASE_LOONGSON_EXT2 0x00004000 /* Loongson EXTensions R2 */
>
> +/*
> + * CPU security vulnerabilities
> + */
> +#define MIPS_VULNBL_MELTDOWN BIT(0)
> +#define MIPS_VULNBL_SPECTRE_V1 BIT(1)
> +#define MIPS_VULNBL_SPECTRE_V2 BIT(2)
> +
> #endif /* _ASM_CPU_H */
> diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
> index 13a26d254829..39abc8ead5e0 100644
> --- a/arch/mips/kernel/Makefile
> +++ b/arch/mips/kernel/Makefile
> @@ -8,7 +8,7 @@ extra-y := head.o vmlinux.lds
> obj-y += cmpxchg.o cpu-probe.o branch.o elf.o entry.o genex.o idle.o irq.o \
> process.o prom.o ptrace.o reset.o setup.o signal.o \
> syscall.o time.o topology.o traps.o unaligned.o watch.o \
> - vdso.o cacheinfo.o
> + vdso.o cacheinfo.o vulnbl.o
>
> ifdef CONFIG_FUNCTION_TRACER
> CFLAGS_REMOVE_ftrace.o = -pg
> diff --git a/arch/mips/kernel/vulnbl.c b/arch/mips/kernel/vulnbl.c
> new file mode 100644
> index 000000000000..fc73da6214fe
> --- /dev/null
> +++ b/arch/mips/kernel/vulnbl.c
> @@ -0,0 +1,46 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2020, Jiaxun Yang <[email protected]>
> + * MIPS CPU vulnerabilities
> + */
> +
> +#include <linux/device.h>
> +
> +#include <asm/cpu-info.h>
> +#include <asm/cpu.h>
> +
> +ssize_t cpu_show_meltdown(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + if (!(boot_cpu_data.vulnerabilities & MIPS_VULNBL_MELTDOWN))
> + return sprintf(buf, "Unknown\n");
> +
> + if (!(boot_cpu_data.vulnerable & MIPS_VULNBL_MELTDOWN))
> + return sprintf(buf, "Not affected\n");
> +
> + return sprintf(buf, "Affected\n");
> +}
> +
> +ssize_t cpu_show_spectre_v1(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + if (!(boot_cpu_data.vulnerabilities & MIPS_VULNBL_SPECTRE_V1))
> + return sprintf(buf, "Unknown\n");
> +
> + if (!(boot_cpu_data.vulnerable & MIPS_VULNBL_SPECTRE_V1))
> + return sprintf(buf, "Not affected\n");
> +
> + return sprintf(buf, "Affected\n");
> +}
> +
> +ssize_t cpu_show_spectre_v2(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + if (!(boot_cpu_data.vulnerabilities & MIPS_VULNBL_SPECTRE_V2))
> + return sprintf(buf, "Unknown\n");
> +
> + if (!(boot_cpu_data.vulnerable & MIPS_VULNBL_SPECTRE_V2))
> + return sprintf(buf, "Not affected\n");
> +
> + return sprintf(buf, "Affected\n");
> +}
> --
> 2.30.0
>
Hi, Jiaxun,
On Wed, Dec 30, 2020 at 11:26 AM Jiaxun Yang <[email protected]> wrote:
>
> Loongson64C is known to be vulnerable to meltdown according to
> PoC from Rui Wang <[email protected]>.
How about Loongson-3A1000/3B1500, and Loongson-2E/2F?
Huacai
>
> Loongson64G defended these side-channel attack by silicon.
>
> Signed-off-by: Jiaxun Yang <[email protected]>
> ---
> arch/mips/kernel/cpu-probe.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
> index 2460783dbdb1..24b21f51353c 100644
> --- a/arch/mips/kernel/cpu-probe.c
> +++ b/arch/mips/kernel/cpu-probe.c
> @@ -2092,6 +2092,8 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
> c->ases |= (MIPS_ASE_LOONGSON_MMI | MIPS_ASE_LOONGSON_CAM |
> MIPS_ASE_LOONGSON_EXT | MIPS_ASE_LOONGSON_EXT2);
> c->ases &= ~MIPS_ASE_VZ; /* VZ of Loongson-3A2000/3000 is incomplete */
> + c->vulnerabilities |= MIPS_VULNBL_MELTDOWN;
> + c->vulnerable |= MIPS_VULNBL_MELTDOWN;
> break;
> case PRID_IMP_LOONGSON_64G:
> c->cputype = CPU_LOONGSON64;
> @@ -2100,6 +2102,8 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
> set_isa(c, MIPS_CPU_ISA_M64R2);
> decode_cpucfg(c);
> c->writecombine = _CACHE_UNCACHED_ACCELERATED;
> + c->vulnerabilities |= MIPS_VULNBL_MELTDOWN |
> + MIPS_VULNBL_SPECTRE_V1 | MIPS_VULNBL_SPECTRE_V2;
> break;
> default:
> panic("Unknown Loongson Processor ID!");
> --
> 2.30.0
>
Hi Jiaxun,
Overall a nice step towards a more conformant arch/mips! Some nits below
though.
On 12/30/20 11:23 AM, Jiaxun Yang wrote:
> Add infrastructure to display CPU vulnerabilities.
> As most MIPS CPU vendors are dead today and we can't confirm
> vulnerabilities states with them, we'll display vulnerabilities
> as "Unknown" by default and override them in cpu-probe.c
Add trailing period.
>
> Signed-off-by: Jiaxun Yang <[email protected]>
> ---
> arch/mips/Kconfig | 1 +
> arch/mips/include/asm/cpu-info.h | 5 ++++
> arch/mips/include/asm/cpu.h | 7 +++++
> arch/mips/kernel/Makefile | 2 +-
> arch/mips/kernel/vulnbl.c | 46 ++++++++++++++++++++++++++++++++
> 5 files changed, 60 insertions(+), 1 deletion(-)
> create mode 100644 arch/mips/kernel/vulnbl.c
>
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index ef5b2a177b1b..524053b8f769 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -24,6 +24,7 @@ config MIPS
> select GENERIC_CLOCKEVENTS
> select GENERIC_CMOS_UPDATE
> select GENERIC_CPU_AUTOPROBE
> + select GENERIC_CPU_VULNERABILITIES
> select GENERIC_GETTIMEOFDAY
> select GENERIC_IOMAP
> select GENERIC_IRQ_PROBE
> diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h
> index a600670d00e9..1a964dbfc0a8 100644
> --- a/arch/mips/include/asm/cpu-info.h
> +++ b/arch/mips/include/asm/cpu-info.h
> @@ -106,6 +106,11 @@ struct cpuinfo_mips {
> unsigned int guestid_mask;
> unsigned int guestid_cache;
>
> + /* Vulnerabilities */
> + unsigned int vulnerabilities; /* Vulnerabilities states that we known */
> + unsigned int vulnerable; /* Vulnerabilities affated */
> + unsigned int mitigations; /* Mitigations */
Could you make the field names a little clearer? Like "known_mask",
"affected_mask" and "mitigated_mask"?
Also I wonder if removing the first mask is okay, since if a bit is
neither "affected" nor "mitigated" then it must belong to the "unknown"
case.
> +
> #ifdef CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION
> /* CPUCFG data for this CPU, synthesized at probe time.
> *
> diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
> index f5b04e8f6061..3414c9f5464e 100644
> --- a/arch/mips/include/asm/cpu.h
> +++ b/arch/mips/include/asm/cpu.h
> @@ -447,4 +447,11 @@ enum cpu_type_enum {
> #define MIPS_ASE_LOONGSON_EXT 0x00002000 /* Loongson EXTensions */
> #define MIPS_ASE_LOONGSON_EXT2 0x00004000 /* Loongson EXTensions R2 */
>
> +/*
> + * CPU security vulnerabilities
> + */
> +#define MIPS_VULNBL_MELTDOWN BIT(0)
> +#define MIPS_VULNBL_SPECTRE_V1 BIT(1)
> +#define MIPS_VULNBL_SPECTRE_V2 BIT(2)
Looking at the arch/x86 vulnerabilities code, I tend to think that
"VULNBL" is not (rather ugly) shorthand for "vulnerability", but
"vulnerability blacklist" (!), because they have "VULNWL" for apparently
"whitelist". So I suggest writing out "VULNERABILITY" fully for clarity.
> +
> #endif /* _ASM_CPU_H */
> diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
> index 13a26d254829..39abc8ead5e0 100644
> --- a/arch/mips/kernel/Makefile
> +++ b/arch/mips/kernel/Makefile
> @@ -8,7 +8,7 @@ extra-y := head.o vmlinux.lds
> obj-y += cmpxchg.o cpu-probe.o branch.o elf.o entry.o genex.o idle.o irq.o \
> process.o prom.o ptrace.o reset.o setup.o signal.o \
> syscall.o time.o topology.o traps.o unaligned.o watch.o \
> - vdso.o cacheinfo.o
> + vdso.o cacheinfo.o vulnbl.o
>
> ifdef CONFIG_FUNCTION_TRACER
> CFLAGS_REMOVE_ftrace.o = -pg
> diff --git a/arch/mips/kernel/vulnbl.c b/arch/mips/kernel/vulnbl.c
> new file mode 100644
> index 000000000000..fc73da6214fe
> --- /dev/null
> +++ b/arch/mips/kernel/vulnbl.c
Same with this filename.
> @@ -0,0 +1,46 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2020, Jiaxun Yang <[email protected]>
> + * MIPS CPU vulnerabilities
> + */
> +
> +#include <linux/device.h>
> +
> +#include <asm/cpu-info.h>
> +#include <asm/cpu.h>
> +
> +ssize_t cpu_show_meltdown(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + if (!(boot_cpu_data.vulnerabilities & MIPS_VULNBL_MELTDOWN))
> + return sprintf(buf, "Unknown\n");
> +
> + if (!(boot_cpu_data.vulnerable & MIPS_VULNBL_MELTDOWN))
> + return sprintf(buf, "Not affected\n");
> +
> + return sprintf(buf, "Affected\n");
Be consistent with other arches and use "Vulnerable"?
> +}
> +
> +ssize_t cpu_show_spectre_v1(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + if (!(boot_cpu_data.vulnerabilities & MIPS_VULNBL_SPECTRE_V1))
> + return sprintf(buf, "Unknown\n");
> +
> + if (!(boot_cpu_data.vulnerable & MIPS_VULNBL_SPECTRE_V1))
> + return sprintf(buf, "Not affected\n");
> +
> + return sprintf(buf, "Affected\n");
Same as above.
> +}
> +
> +ssize_t cpu_show_spectre_v2(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + if (!(boot_cpu_data.vulnerabilities & MIPS_VULNBL_SPECTRE_V2))
> + return sprintf(buf, "Unknown\n");
> +
> + if (!(boot_cpu_data.vulnerable & MIPS_VULNBL_SPECTRE_V2))
> + return sprintf(buf, "Not affected\n");
> +
> + return sprintf(buf, "Affected\n");
Same as above.
> +}
Hi Jiaxun,
On 12/30/20 11:23 AM, Jiaxun Yang wrote:
> Loongson64C is known to be vulnerable to meltdown according to
> PoC from Rui Wang <[email protected]>.
>
> Loongson64G defended these side-channel attack by silicon.
"Loongson64G mitigated it in hardware"?
>
> Signed-off-by: Jiaxun Yang <[email protected]>
> ---
> arch/mips/kernel/cpu-probe.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
> index 2460783dbdb1..24b21f51353c 100644
> --- a/arch/mips/kernel/cpu-probe.c
> +++ b/arch/mips/kernel/cpu-probe.c
> @@ -2092,6 +2092,8 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
> c->ases |= (MIPS_ASE_LOONGSON_MMI | MIPS_ASE_LOONGSON_CAM |
> MIPS_ASE_LOONGSON_EXT | MIPS_ASE_LOONGSON_EXT2);
> c->ases &= ~MIPS_ASE_VZ; /* VZ of Loongson-3A2000/3000 is incomplete */
> + c->vulnerabilities |= MIPS_VULNBL_MELTDOWN;
> + c->vulnerable |= MIPS_VULNBL_MELTDOWN;
> break;
> case PRID_IMP_LOONGSON_64G:
> c->cputype = CPU_LOONGSON64;
> @@ -2100,6 +2102,8 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
> set_isa(c, MIPS_CPU_ISA_M64R2);
> decode_cpucfg(c);
> c->writecombine = _CACHE_UNCACHED_ACCELERATED;
> + c->vulnerabilities |= MIPS_VULNBL_MELTDOWN |
> + MIPS_VULNBL_SPECTRE_V1 | MIPS_VULNBL_SPECTRE_V2;
Of course you forgot to set the "mitigated" mask... Oh wait.
It seems the "mitigated" mask in the 1st patch is never used, so either
code there or here must be amended.
> break;
> default:
> panic("Unknown Loongson Processor ID!");
在 2020/12/31 23:43, WANG Xuerui 写道:
> Hi Jiaxun,
>
> On 12/30/20 11:23 AM, Jiaxun Yang wrote:
>> Loongson64C is known to be vulnerable to meltdown according to
>> PoC from Rui Wang <[email protected]>.
>>
>> Loongson64G defended these side-channel attack by silicon.
> "Loongson64G mitigated it in hardware"?
>>
>> Signed-off-by: Jiaxun Yang <[email protected]>
>> ---
>> arch/mips/kernel/cpu-probe.c | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
>> index 2460783dbdb1..24b21f51353c 100644
>> --- a/arch/mips/kernel/cpu-probe.c
>> +++ b/arch/mips/kernel/cpu-probe.c
>> @@ -2092,6 +2092,8 @@ static inline void cpu_probe_loongson(struct
>> cpuinfo_mips *c, unsigned int cpu)
>> c->ases |= (MIPS_ASE_LOONGSON_MMI | MIPS_ASE_LOONGSON_CAM |
>> MIPS_ASE_LOONGSON_EXT | MIPS_ASE_LOONGSON_EXT2);
>> c->ases &= ~MIPS_ASE_VZ; /* VZ of Loongson-3A2000/3000 is
>> incomplete */
>> + c->vulnerabilities |= MIPS_VULNBL_MELTDOWN;
>> + c->vulnerable |= MIPS_VULNBL_MELTDOWN;
>> break;
>> case PRID_IMP_LOONGSON_64G:
>> c->cputype = CPU_LOONGSON64;
>> @@ -2100,6 +2102,8 @@ static inline void cpu_probe_loongson(struct
>> cpuinfo_mips *c, unsigned int cpu)
>> set_isa(c, MIPS_CPU_ISA_M64R2);
>> decode_cpucfg(c);
>> c->writecombine = _CACHE_UNCACHED_ACCELERATED;
>> + c->vulnerabilities |= MIPS_VULNBL_MELTDOWN |
>> + MIPS_VULNBL_SPECTRE_V1 | MIPS_VULNBL_SPECTRE_V2;
>
> Of course you forgot to set the "mitigated" mask... Oh wait.
Hi Xuerui,
Actually it belongs to not affected category as there is no action
to take in kernel.
>
> It seems the "mitigated" mask in the 1st patch is never used, so
> either code there or here must be amended.
Yes, it's just a place holder for future kernel mitigations~
Or I should leave it until we find out these mitigations?
Thanks.
- Jiaxun
>
>> break;
>> default:
>> panic("Unknown Loongson Processor ID!");
在 2020/12/31 23:38, WANG Xuerui 写道:
> Hi Jiaxun,
>
> Overall a nice step towards a more conformant arch/mips! Some nits
> below though.
>
>
> On 12/30/20 11:23 AM, Jiaxun Yang wrote:
>> Add infrastructure to display CPU vulnerabilities.
>> As most MIPS CPU vendors are dead today and we can't confirm
>> vulnerabilities states with them, we'll display vulnerabilities
>> as "Unknown" by default and override them in cpu-probe.c
> Add trailing period.
>>
>> Signed-off-by: Jiaxun Yang <[email protected]>
>> ---
>> arch/mips/Kconfig | 1 +
>> arch/mips/include/asm/cpu-info.h | 5 ++++
>> arch/mips/include/asm/cpu.h | 7 +++++
>> arch/mips/kernel/Makefile | 2 +-
>> arch/mips/kernel/vulnbl.c | 46 ++++++++++++++++++++++++++++++++
>> 5 files changed, 60 insertions(+), 1 deletion(-)
>> create mode 100644 arch/mips/kernel/vulnbl.c
>>
>> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
>> index ef5b2a177b1b..524053b8f769 100644
>> --- a/arch/mips/Kconfig
>> +++ b/arch/mips/Kconfig
>> @@ -24,6 +24,7 @@ config MIPS
>> select GENERIC_CLOCKEVENTS
>> select GENERIC_CMOS_UPDATE
>> select GENERIC_CPU_AUTOPROBE
>> + select GENERIC_CPU_VULNERABILITIES
>> select GENERIC_GETTIMEOFDAY
>> select GENERIC_IOMAP
>> select GENERIC_IRQ_PROBE
>> diff --git a/arch/mips/include/asm/cpu-info.h
>> b/arch/mips/include/asm/cpu-info.h
>> index a600670d00e9..1a964dbfc0a8 100644
>> --- a/arch/mips/include/asm/cpu-info.h
>> +++ b/arch/mips/include/asm/cpu-info.h
>> @@ -106,6 +106,11 @@ struct cpuinfo_mips {
>> unsigned int guestid_mask;
>> unsigned int guestid_cache;
>> + /* Vulnerabilities */
>> + unsigned int vulnerabilities; /* Vulnerabilities states
>> that we known */
>> + unsigned int vulnerable; /* Vulnerabilities affated */
>> + unsigned int mitigations; /* Mitigations */
>
> Could you make the field names a little clearer? Like "known_mask",
> "affected_mask" and "mitigated_mask"?
>
> Also I wonder if removing the first mask is okay, since if a bit is
> neither "affected" nor "mitigated" then it must belong to the
> "unknown" case.
Actually we have no way to mitigate them in kernel for now :-(
>
>> +
>> #ifdef CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION
>> /* CPUCFG data for this CPU, synthesized at probe time.
>> *
>> diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
>> index f5b04e8f6061..3414c9f5464e 100644
>> --- a/arch/mips/include/asm/cpu.h
>> +++ b/arch/mips/include/asm/cpu.h
>> @@ -447,4 +447,11 @@ enum cpu_type_enum {
>> #define MIPS_ASE_LOONGSON_EXT 0x00002000 /* Loongson EXTensions */
>> #define MIPS_ASE_LOONGSON_EXT2 0x00004000 /* Loongson EXTensions
>> R2 */
>> +/*
>> + * CPU security vulnerabilities
>> + */
>> +#define MIPS_VULNBL_MELTDOWN BIT(0)
>> +#define MIPS_VULNBL_SPECTRE_V1 BIT(1)
>> +#define MIPS_VULNBL_SPECTRE_V2 BIT(2)
> Looking at the arch/x86 vulnerabilities code, I tend to think that
> "VULNBL" is not (rather ugly) shorthand for "vulnerability", but
> "vulnerability blacklist" (!), because they have "VULNWL" for
> apparently "whitelist". So I suggest writing out "VULNERABILITY" fully
> for clarity.
>> +
>> #endif /* _ASM_CPU_H */
>> diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
>> index 13a26d254829..39abc8ead5e0 100644
>> --- a/arch/mips/kernel/Makefile
>> +++ b/arch/mips/kernel/Makefile
>> @@ -8,7 +8,7 @@ extra-y := head.o vmlinux.lds
>> obj-y += cmpxchg.o cpu-probe.o branch.o elf.o entry.o
>> genex.o idle.o irq.o \
>> process.o prom.o ptrace.o reset.o setup.o signal.o \
>> syscall.o time.o topology.o traps.o unaligned.o watch.o \
>> - vdso.o cacheinfo.o
>> + vdso.o cacheinfo.o vulnbl.o
>> ifdef CONFIG_FUNCTION_TRACER
>> CFLAGS_REMOVE_ftrace.o = -pg
>> diff --git a/arch/mips/kernel/vulnbl.c b/arch/mips/kernel/vulnbl.c
>> new file mode 100644
>> index 000000000000..fc73da6214fe
>> --- /dev/null
>> +++ b/arch/mips/kernel/vulnbl.c
> Same with this filename.
>> @@ -0,0 +1,46 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (C) 2020, Jiaxun Yang <[email protected]>
>> + * MIPS CPU vulnerabilities
>> + */
>> +
>> +#include <linux/device.h>
>> +
>> +#include <asm/cpu-info.h>
>> +#include <asm/cpu.h>
>> +
>> +ssize_t cpu_show_meltdown(struct device *dev,
>> + struct device_attribute *attr, char *buf)
>> +{
>> + if (!(boot_cpu_data.vulnerabilities & MIPS_VULNBL_MELTDOWN))
>> + return sprintf(buf, "Unknown\n");
>> +
>> + if (!(boot_cpu_data.vulnerable & MIPS_VULNBL_MELTDOWN))
>> + return sprintf(buf, "Not affected\n");
>> +
>> + return sprintf(buf, "Affected\n");
> Be consistent with other arches and use "Vulnerable"?
>> +}
>> +
>> +ssize_t cpu_show_spectre_v1(struct device *dev,
>> + struct device_attribute *attr, char *buf)
>> +{
>> + if (!(boot_cpu_data.vulnerabilities & MIPS_VULNBL_SPECTRE_V1))
>> + return sprintf(buf, "Unknown\n");
>> +
>> + if (!(boot_cpu_data.vulnerable & MIPS_VULNBL_SPECTRE_V1))
>> + return sprintf(buf, "Not affected\n");
>> +
>> + return sprintf(buf, "Affected\n");
> Same as above.
>> +}
>> +
>> +ssize_t cpu_show_spectre_v2(struct device *dev,
>> + struct device_attribute *attr, char *buf)
>> +{
>> + if (!(boot_cpu_data.vulnerabilities & MIPS_VULNBL_SPECTRE_V2))
>> + return sprintf(buf, "Unknown\n");
>> +
>> + if (!(boot_cpu_data.vulnerable & MIPS_VULNBL_SPECTRE_V2))
>> + return sprintf(buf, "Not affected\n");
>> +
>> + return sprintf(buf, "Affected\n");
> Same as above.
>> +}