[v2,3/8] mips: compat: vdso: Use legacy syscalls as fallback
diff mbox series

Message ID 20190830135902.20861-4-vincenzo.frascino@arm.com
State New
Headers show
Series
  • vdso: Complete the conversion to 32bit syscalls
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Commit Message

Vincenzo Frascino Aug. 30, 2019, 1:58 p.m. UTC
The generic VDSO implementation uses the Y2038 safe clock_gettime64() and
clock_getres_time64() syscalls as fallback for 32bit VDSO. This breaks
seccomp setups because these syscalls might be not (yet) allowed.

Implement the 32bit variants which use the legacy syscalls and select the
variant in the core library.

The 64bit time variants are not removed because they are required for the
time64 based vdso accessors.

Cc: Paul Burton <paul.burton@mips.com>
Fixes: 00b26474c2f1 ("lib/vdso: Provide generic VDSO implementation")
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 arch/mips/include/asm/vdso/gettimeofday.h | 45 +++++++++++++++++++++++
 arch/mips/vdso/config-n32-o32-env.c       |  1 +
 2 files changed, 46 insertions(+)

Comments

Paul Burton Sept. 3, 2019, 1:52 p.m. UTC | #1
Hi Vincenzo,

On Fri, Aug 30, 2019 at 02:58:57PM +0100, Vincenzo Frascino wrote:
> The generic VDSO implementation uses the Y2038 safe clock_gettime64() and
> clock_getres_time64() syscalls as fallback for 32bit VDSO. This breaks
> seccomp setups because these syscalls might be not (yet) allowed.
> 
> Implement the 32bit variants which use the legacy syscalls and select the
> variant in the core library.
> 
> The 64bit time variants are not removed because they are required for the
> time64 based vdso accessors.
> 
> Cc: Paul Burton <paul.burton@mips.com>
> Fixes: 00b26474c2f1 ("lib/vdso: Provide generic VDSO implementation")
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

How would you like this to be applied? I'd be happy to apply this one to
mips-next, where commit 24640f233b46 ("mips: Add support for generic
vDSO") added the file being modified here. Otherwise:

    Acked-by: Paul Burton <paul.burton@mips.com>

Thanks,
    Paul

> ---
>  arch/mips/include/asm/vdso/gettimeofday.h | 45 +++++++++++++++++++++++
>  arch/mips/vdso/config-n32-o32-env.c       |  1 +
>  2 files changed, 46 insertions(+)
> 
> diff --git a/arch/mips/include/asm/vdso/gettimeofday.h b/arch/mips/include/asm/vdso/gettimeofday.h
> index c59fe08b0347..e78462e8ca2e 100644
> --- a/arch/mips/include/asm/vdso/gettimeofday.h
> +++ b/arch/mips/include/asm/vdso/gettimeofday.h
> @@ -105,6 +105,51 @@ static __always_inline int clock_getres_fallback(
>  	return error ? -ret : ret;
>  }
>  
> +#if _MIPS_SIM != _MIPS_SIM_ABI64
> +
> +#define VDSO_HAS_32BIT_FALLBACK	1
> +
> +static __always_inline long clock_gettime32_fallback(
> +					clockid_t _clkid,
> +					struct old_timespec32 *_ts)
> +{
> +	register struct old_timespec32 *ts asm("a1") = _ts;
> +	register clockid_t clkid asm("a0") = _clkid;
> +	register long ret asm("v0");
> +	register long nr asm("v0") = __NR_clock_gettime;
> +	register long error asm("a3");
> +
> +	asm volatile(
> +	"       syscall\n"
> +	: "=r" (ret), "=r" (error)
> +	: "r" (clkid), "r" (ts), "r" (nr)
> +	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
> +	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
> +
> +	return error ? -ret : ret;
> +}
> +
> +static __always_inline int clock_getres32_fallback(
> +					clockid_t _clkid,
> +					struct old_timespec32 *_ts)
> +{
> +	register struct old_timespec32 *ts asm("a1") = _ts;
> +	register clockid_t clkid asm("a0") = _clkid;
> +	register long ret asm("v0");
> +	register long nr asm("v0") = __NR_clock_getres;
> +	register long error asm("a3");
> +
> +	asm volatile(
> +	"       syscall\n"
> +	: "=r" (ret), "=r" (error)
> +	: "r" (clkid), "r" (ts), "r" (nr)
> +	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
> +	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
> +
> +	return error ? -ret : ret;
> +}
> +#endif
> +
>  #ifdef CONFIG_CSRC_R4K
>  
>  static __always_inline u64 read_r4k_count(void)
> diff --git a/arch/mips/vdso/config-n32-o32-env.c b/arch/mips/vdso/config-n32-o32-env.c
> index 7f8d957abd4a..0011a632aef2 100644
> --- a/arch/mips/vdso/config-n32-o32-env.c
> +++ b/arch/mips/vdso/config-n32-o32-env.c
> @@ -10,6 +10,7 @@
>   */
>  #undef CONFIG_64BIT
>  
> +#define BUILD_VDSO32
>  #define CONFIG_32BIT 1
>  #define CONFIG_GENERIC_ATOMIC64 1
>  #define BUILD_VDSO32_64
> -- 
> 2.23.0
>
Vincenzo Frascino Sept. 3, 2019, 2:20 p.m. UTC | #2
Hi Paul,

thank you for your review.

On 9/3/19 2:52 PM, Paul Burton wrote:
> Hi Vincenzo,
> 
> On Fri, Aug 30, 2019 at 02:58:57PM +0100, Vincenzo Frascino wrote:
>> The generic VDSO implementation uses the Y2038 safe clock_gettime64() and
>> clock_getres_time64() syscalls as fallback for 32bit VDSO. This breaks
>> seccomp setups because these syscalls might be not (yet) allowed.
>>
>> Implement the 32bit variants which use the legacy syscalls and select the
>> variant in the core library.
>>
>> The 64bit time variants are not removed because they are required for the
>> time64 based vdso accessors.
>>
>> Cc: Paul Burton <paul.burton@mips.com>
>> Fixes: 00b26474c2f1 ("lib/vdso: Provide generic VDSO implementation")
>> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
> 
> How would you like this to be applied? I'd be happy to apply this one to
> mips-next, where commit 24640f233b46 ("mips: Add support for generic
> vDSO") added the file being modified here. Otherwise:
> 
>     Acked-by: Paul Burton <paul.burton@mips.com>
> 

Please feel free to apply this to mips-next.

Thanks,
Vincenzo

> Thanks,
>     Paul
> 
>> ---
>>  arch/mips/include/asm/vdso/gettimeofday.h | 45 +++++++++++++++++++++++
>>  arch/mips/vdso/config-n32-o32-env.c       |  1 +
>>  2 files changed, 46 insertions(+)
>>
>> diff --git a/arch/mips/include/asm/vdso/gettimeofday.h b/arch/mips/include/asm/vdso/gettimeofday.h
>> index c59fe08b0347..e78462e8ca2e 100644
>> --- a/arch/mips/include/asm/vdso/gettimeofday.h
>> +++ b/arch/mips/include/asm/vdso/gettimeofday.h
>> @@ -105,6 +105,51 @@ static __always_inline int clock_getres_fallback(
>>  	return error ? -ret : ret;
>>  }
>>  
>> +#if _MIPS_SIM != _MIPS_SIM_ABI64
>> +
>> +#define VDSO_HAS_32BIT_FALLBACK	1
>> +
>> +static __always_inline long clock_gettime32_fallback(
>> +					clockid_t _clkid,
>> +					struct old_timespec32 *_ts)
>> +{
>> +	register struct old_timespec32 *ts asm("a1") = _ts;
>> +	register clockid_t clkid asm("a0") = _clkid;
>> +	register long ret asm("v0");
>> +	register long nr asm("v0") = __NR_clock_gettime;
>> +	register long error asm("a3");
>> +
>> +	asm volatile(
>> +	"       syscall\n"
>> +	: "=r" (ret), "=r" (error)
>> +	: "r" (clkid), "r" (ts), "r" (nr)
>> +	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
>> +	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
>> +
>> +	return error ? -ret : ret;
>> +}
>> +
>> +static __always_inline int clock_getres32_fallback(
>> +					clockid_t _clkid,
>> +					struct old_timespec32 *_ts)
>> +{
>> +	register struct old_timespec32 *ts asm("a1") = _ts;
>> +	register clockid_t clkid asm("a0") = _clkid;
>> +	register long ret asm("v0");
>> +	register long nr asm("v0") = __NR_clock_getres;
>> +	register long error asm("a3");
>> +
>> +	asm volatile(
>> +	"       syscall\n"
>> +	: "=r" (ret), "=r" (error)
>> +	: "r" (clkid), "r" (ts), "r" (nr)
>> +	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
>> +	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
>> +
>> +	return error ? -ret : ret;
>> +}
>> +#endif
>> +
>>  #ifdef CONFIG_CSRC_R4K
>>  
>>  static __always_inline u64 read_r4k_count(void)
>> diff --git a/arch/mips/vdso/config-n32-o32-env.c b/arch/mips/vdso/config-n32-o32-env.c
>> index 7f8d957abd4a..0011a632aef2 100644
>> --- a/arch/mips/vdso/config-n32-o32-env.c
>> +++ b/arch/mips/vdso/config-n32-o32-env.c
>> @@ -10,6 +10,7 @@
>>   */
>>  #undef CONFIG_64BIT
>>  
>> +#define BUILD_VDSO32
>>  #define CONFIG_32BIT 1
>>  #define CONFIG_GENERIC_ATOMIC64 1
>>  #define BUILD_VDSO32_64
>> -- 
>> 2.23.0
>>
Paul Burton Sept. 3, 2019, 9 p.m. UTC | #3
Hello,

Vincenzo Frascino wrote:
> The generic VDSO implementation uses the Y2038 safe clock_gettime64() and
> clock_getres_time64() syscalls as fallback for 32bit VDSO. This breaks
> seccomp setups because these syscalls might be not (yet) allowed.
> 
> Implement the 32bit variants which use the legacy syscalls and select the
> variant in the core library.
> 
> The 64bit time variants are not removed because they are required for the
> time64 based vdso accessors.

Applied to mips-next.

> commit 932bb934ed4d
> https://git.kernel.org/mips/c/932bb934ed4d
> 
> Fixes: 00b26474c2f1 ("lib/vdso: Provide generic VDSO implementation")
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
> Signed-off-by: Paul Burton <paul.burton@mips.com>

Thanks,
    Paul

[ This message was auto-generated; if you believe anything is incorrect
  then please email paul.burton@mips.com to report it. ]

Patch
diff mbox series

diff --git a/arch/mips/include/asm/vdso/gettimeofday.h b/arch/mips/include/asm/vdso/gettimeofday.h
index c59fe08b0347..e78462e8ca2e 100644
--- a/arch/mips/include/asm/vdso/gettimeofday.h
+++ b/arch/mips/include/asm/vdso/gettimeofday.h
@@ -105,6 +105,51 @@  static __always_inline int clock_getres_fallback(
 	return error ? -ret : ret;
 }
 
+#if _MIPS_SIM != _MIPS_SIM_ABI64
+
+#define VDSO_HAS_32BIT_FALLBACK	1
+
+static __always_inline long clock_gettime32_fallback(
+					clockid_t _clkid,
+					struct old_timespec32 *_ts)
+{
+	register struct old_timespec32 *ts asm("a1") = _ts;
+	register clockid_t clkid asm("a0") = _clkid;
+	register long ret asm("v0");
+	register long nr asm("v0") = __NR_clock_gettime;
+	register long error asm("a3");
+
+	asm volatile(
+	"       syscall\n"
+	: "=r" (ret), "=r" (error)
+	: "r" (clkid), "r" (ts), "r" (nr)
+	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
+	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
+
+	return error ? -ret : ret;
+}
+
+static __always_inline int clock_getres32_fallback(
+					clockid_t _clkid,
+					struct old_timespec32 *_ts)
+{
+	register struct old_timespec32 *ts asm("a1") = _ts;
+	register clockid_t clkid asm("a0") = _clkid;
+	register long ret asm("v0");
+	register long nr asm("v0") = __NR_clock_getres;
+	register long error asm("a3");
+
+	asm volatile(
+	"       syscall\n"
+	: "=r" (ret), "=r" (error)
+	: "r" (clkid), "r" (ts), "r" (nr)
+	: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
+	  "$14", "$15", "$24", "$25", "hi", "lo", "memory");
+
+	return error ? -ret : ret;
+}
+#endif
+
 #ifdef CONFIG_CSRC_R4K
 
 static __always_inline u64 read_r4k_count(void)
diff --git a/arch/mips/vdso/config-n32-o32-env.c b/arch/mips/vdso/config-n32-o32-env.c
index 7f8d957abd4a..0011a632aef2 100644
--- a/arch/mips/vdso/config-n32-o32-env.c
+++ b/arch/mips/vdso/config-n32-o32-env.c
@@ -10,6 +10,7 @@ 
  */
 #undef CONFIG_64BIT
 
+#define BUILD_VDSO32
 #define CONFIG_32BIT 1
 #define CONFIG_GENERIC_ATOMIC64 1
 #define BUILD_VDSO32_64