[PATCH 0/4] linux-user: prctl follow-ups

[PATCH 0/4] linux-user: prctl follow-ups

[Richard Henderson]

Hi Laurent, as requested.  I did all of the cap_task_prctl options,
and fixed a few existing bugs with PR_GET_DEATHSIG.

r~

Richard Henderson (4):
  linux-user: Do not special-case NULL for PR_GET_PDEATHSIG
  linux-user: Map signal number in PR_GET_PDEATHSIG
  linux-user: Implement PR_SET_PDEATHSIG
  linux-user: Implement capability prctls

 linux-user/syscall.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

-- 
2.25.1

[PATCH 1/4] linux-user: Do not special-case NULL for PR_GET_PDEATHSIG

[Richard Henderson]

The kernel does not special-case arg2 != NULL, so
neither should we.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 linux-user/syscall.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index ce9d64896c..e8f9e0643e 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -6444,7 +6444,7 @@ static abi_long do_prctl(CPUArchState *env, abi_long option, abi_long arg2,
             int deathsig;
             ret = get_errno(prctl(PR_GET_PDEATHSIG, &deathsig,
                                   arg3, arg4, arg5));
-            if (!is_error(ret) && arg2 && put_user_s32(deathsig, arg2)) {
+            if (!is_error(ret) && put_user_s32(deathsig, arg2)) {
                 return -TARGET_EFAULT;
             }
             return ret;
-- 
2.25.1

Re: [PATCH 1/4] linux-user: Do not special-case NULL for PR_GET_PDEATHSIG

[Laurent Vivier]

Le 06/01/2022 à 23:57, Richard Henderson a écrit :
> The kernel does not special-case arg2 != NULL, so
> neither should we.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   linux-user/syscall.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index ce9d64896c..e8f9e0643e 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -6444,7 +6444,7 @@ static abi_long do_prctl(CPUArchState *env, abi_long option, abi_long arg2,
>               int deathsig;
>               ret = get_errno(prctl(PR_GET_PDEATHSIG, &deathsig,
>                                     arg3, arg4, arg5));
> -            if (!is_error(ret) && arg2 && put_user_s32(deathsig, arg2)) {
> +            if (!is_error(ret) && put_user_s32(deathsig, arg2)) {
>                   return -TARGET_EFAULT;
>               }
>               return ret;

Reviewed-by: Laurent Vivier <laurent@vivier.eu>

Re: [PATCH 1/4] linux-user: Do not special-case NULL for PR_GET_PDEATHSIG

[Laurent Vivier]

Le 08/01/2022 à 18:10, Laurent Vivier a écrit :
> Le 06/01/2022 à 23:57, Richard Henderson a écrit :
>> The kernel does not special-case arg2 != NULL, so
>> neither should we.
>>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
>>   linux-user/syscall.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
>> index ce9d64896c..e8f9e0643e 100644
>> --- a/linux-user/syscall.c
>> +++ b/linux-user/syscall.c
>> @@ -6444,7 +6444,7 @@ static abi_long do_prctl(CPUArchState *env, abi_long option, abi_long arg2,
>>               int deathsig;
>>               ret = get_errno(prctl(PR_GET_PDEATHSIG, &deathsig,
>>                                     arg3, arg4, arg5));
>> -            if (!is_error(ret) && arg2 && put_user_s32(deathsig, arg2)) {
>> +            if (!is_error(ret) && put_user_s32(deathsig, arg2)) {
>>                   return -TARGET_EFAULT;
>>               }
>>               return ret;
> 
> Reviewed-by: Laurent Vivier <laurent@vivier.eu>
> 

Reviewed-by: Laurent Vivier <laurent@vivier.eu>

[PATCH 2/4] linux-user: Map signal number in PR_GET_PDEATHSIG

[Richard Henderson]

Convert the host signal number to guest signal number
before returning the value to the guest.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 linux-user/syscall.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index e8f9e0643e..9eb2fb2bb2 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -6444,7 +6444,8 @@ static abi_long do_prctl(CPUArchState *env, abi_long option, abi_long arg2,
             int deathsig;
             ret = get_errno(prctl(PR_GET_PDEATHSIG, &deathsig,
                                   arg3, arg4, arg5));
-            if (!is_error(ret) && put_user_s32(deathsig, arg2)) {
+            if (!is_error(ret) &&
+                put_user_s32(host_to_target_signal(deathsig), arg2)) {
                 return -TARGET_EFAULT;
             }
             return ret;
-- 
2.25.1

Re: [PATCH 2/4] linux-user: Map signal number in PR_GET_PDEATHSIG

[Philippe Mathieu-Daudé]

On 6/1/22 23:57, Richard Henderson wrote:
> Convert the host signal number to guest signal number
> before returning the value to the guest.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   linux-user/syscall.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

[PATCH 3/4] linux-user: Implement PR_SET_PDEATHSIG

[Richard Henderson]

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 linux-user/syscall.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 9eb2fb2bb2..8495f5e08e 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -6450,6 +6450,9 @@ static abi_long do_prctl(CPUArchState *env, abi_long option, abi_long arg2,
             }
             return ret;
         }
+    case PR_SET_PDEATHSIG:
+        return get_errno(prctl(PR_SET_PDEATHSIG, target_to_host_signal(arg2),
+                               arg3, arg4, arg5));
     case PR_GET_NAME:
         {
             void *name = lock_user(VERIFY_WRITE, arg2, 16, 1);
-- 
2.25.1

Re: [PATCH 3/4] linux-user: Implement PR_SET_PDEATHSIG

[Laurent Vivier]

Le 06/01/2022 à 23:57, Richard Henderson a écrit :
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   linux-user/syscall.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 9eb2fb2bb2..8495f5e08e 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -6450,6 +6450,9 @@ static abi_long do_prctl(CPUArchState *env, abi_long option, abi_long arg2,
>               }
>               return ret;
>           }
> +    case PR_SET_PDEATHSIG:
> +        return get_errno(prctl(PR_SET_PDEATHSIG, target_to_host_signal(arg2),
> +                               arg3, arg4, arg5));
>       case PR_GET_NAME:
>           {
>               void *name = lock_user(VERIFY_WRITE, arg2, 16, 1);

Reviewed-by: Laurent Vivier <laurent@vivier.eu>

[PATCH 4/4] linux-user: Implement capability prctls

[Richard Henderson]

This is PR_CAPBSET_READ, PR_CAPBSET_DROP and the "legacy"
PR_CAP_AMBIENT PR_GET_SECUREBITS, PR_SET_SECUREBITS.

All of these arguments are integer values only, and do not
require mapping of values between host and guest.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 linux-user/syscall.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 8495f5e08e..4711afaf8c 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -6504,10 +6504,15 @@ static abi_long do_prctl(CPUArchState *env, abi_long option, abi_long arg2,
     case PR_SET_UNALIGN:
         return do_prctl_set_unalign(env, arg2);
 
+    case PR_CAP_AMBIENT:
+    case PR_CAPBSET_READ:
+    case PR_CAPBSET_DROP:
     case PR_GET_DUMPABLE:
     case PR_SET_DUMPABLE:
     case PR_GET_KEEPCAPS:
     case PR_SET_KEEPCAPS:
+    case PR_GET_SECUREBITS:
+    case PR_SET_SECUREBITS:
     case PR_GET_TIMING:
     case PR_SET_TIMING:
     case PR_GET_TIMERSLACK:
-- 
2.25.1

Re: [PATCH 4/4] linux-user: Implement capability prctls

[Laurent Vivier]

Le 06/01/2022 à 23:57, Richard Henderson a écrit :
> This is PR_CAPBSET_READ, PR_CAPBSET_DROP and the "legacy"
> PR_CAP_AMBIENT PR_GET_SECUREBITS, PR_SET_SECUREBITS.
> 
> All of these arguments are integer values only, and do not
> require mapping of values between host and guest.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   linux-user/syscall.c | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 8495f5e08e..4711afaf8c 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -6504,10 +6504,15 @@ static abi_long do_prctl(CPUArchState *env, abi_long option, abi_long arg2,
>       case PR_SET_UNALIGN:
>           return do_prctl_set_unalign(env, arg2);
>   
> +    case PR_CAP_AMBIENT:
> +    case PR_CAPBSET_READ:
> +    case PR_CAPBSET_DROP:
>       case PR_GET_DUMPABLE:
>       case PR_SET_DUMPABLE:
>       case PR_GET_KEEPCAPS:
>       case PR_SET_KEEPCAPS:
> +    case PR_GET_SECUREBITS:
> +    case PR_SET_SECUREBITS:
>       case PR_GET_TIMING:
>       case PR_SET_TIMING:
>       case PR_GET_TIMERSLACK:

Reviewed-by: Laurent Vivier <laurent@vivier.eu>

Re: [PATCH 0/4] linux-user: prctl follow-ups

[Laurent Vivier]

Le 06/01/2022 à 23:57, Richard Henderson a écrit :
> Hi Laurent, as requested.  I did all of the cap_task_prctl options,
> and fixed a few existing bugs with PR_GET_DEATHSIG.
> 
> r~
> 
> Richard Henderson (4):
>    linux-user: Do not special-case NULL for PR_GET_PDEATHSIG
>    linux-user: Map signal number in PR_GET_PDEATHSIG
>    linux-user: Implement PR_SET_PDEATHSIG
>    linux-user: Implement capability prctls
> 
>   linux-user/syscall.c | 11 ++++++++++-
>   1 file changed, 10 insertions(+), 1 deletion(-)
> 

Series applied to my linux-user-for-7.0 branch.

Thanks,
Laurent