* [PATCH] mm/pkeys: generate pkey system call code only if ARCH_HAS_PKEYS is selected
@ 2016-11-14 11:12 ` Heiko Carstens
0 siblings, 0 replies; 4+ messages in thread
From: Heiko Carstens @ 2016-11-14 11:12 UTC (permalink / raw)
To: Andrew Morton
Cc: linux-arch, linux-kernel, linux-mm, Dave Hansen, Mark Rutland
Having code for the pkey_mprotect, pkey_alloc and pkey_free system
calls makes only sense if ARCH_HAS_PKEYS is selected. If not selected
these system calls will always return -ENOSPC or -EINVAL.
To simplify things and have less code generate the pkey system call
code only if ARCH_HAS_PKEYS is selected.
For architectures which have already wired up the system calls, but do
not select ARCH_HAS_PKEYS this will result in less generated code and
a different return code: the three system calls will now always return
-ENOSYS, using the cond_syscall mechanism.
For architectures which have not wired up the system calls less
unreachable code will be generated.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
---
mm/mprotect.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 11936526b08b..a06e91c4de29 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -484,6 +484,8 @@ SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
return do_mprotect_pkey(start, len, prot, -1);
}
+#ifdef CONFIG_ARCH_HAS_PKEYS
+
SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len,
unsigned long, prot, int, pkey)
{
@@ -534,3 +536,5 @@ SYSCALL_DEFINE1(pkey_free, int, pkey)
*/
return ret;
}
+
+#endif /* CONFIG_ARCH_HAS_PKEYS */
--
2.8.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH] mm/pkeys: generate pkey system call code only if ARCH_HAS_PKEYS is selected
@ 2016-11-14 11:12 ` Heiko Carstens
0 siblings, 0 replies; 4+ messages in thread
From: Heiko Carstens @ 2016-11-14 11:12 UTC (permalink / raw)
To: Andrew Morton
Cc: linux-arch, linux-kernel, linux-mm, Dave Hansen, Mark Rutland
Having code for the pkey_mprotect, pkey_alloc and pkey_free system
calls makes only sense if ARCH_HAS_PKEYS is selected. If not selected
these system calls will always return -ENOSPC or -EINVAL.
To simplify things and have less code generate the pkey system call
code only if ARCH_HAS_PKEYS is selected.
For architectures which have already wired up the system calls, but do
not select ARCH_HAS_PKEYS this will result in less generated code and
a different return code: the three system calls will now always return
-ENOSYS, using the cond_syscall mechanism.
For architectures which have not wired up the system calls less
unreachable code will be generated.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
---
mm/mprotect.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 11936526b08b..a06e91c4de29 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -484,6 +484,8 @@ SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
return do_mprotect_pkey(start, len, prot, -1);
}
+#ifdef CONFIG_ARCH_HAS_PKEYS
+
SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len,
unsigned long, prot, int, pkey)
{
@@ -534,3 +536,5 @@ SYSCALL_DEFINE1(pkey_free, int, pkey)
*/
return ret;
}
+
+#endif /* CONFIG_ARCH_HAS_PKEYS */
--
2.8.4
--
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^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] mm/pkeys: generate pkey system call code only if ARCH_HAS_PKEYS is selected
2016-11-14 11:12 ` Heiko Carstens
@ 2016-11-14 16:44 ` Dave Hansen
-1 siblings, 0 replies; 4+ messages in thread
From: Dave Hansen @ 2016-11-14 16:44 UTC (permalink / raw)
To: Heiko Carstens, Andrew Morton
Cc: linux-arch, linux-kernel, linux-mm, Mark Rutland
On 11/14/2016 03:12 AM, Heiko Carstens wrote:
> Having code for the pkey_mprotect, pkey_alloc and pkey_free system
> calls makes only sense if ARCH_HAS_PKEYS is selected. If not selected
> these system calls will always return -ENOSPC or -EINVAL.
>
> To simplify things and have less code generate the pkey system call
> code only if ARCH_HAS_PKEYS is selected.
>
> For architectures which have already wired up the system calls, but do
> not select ARCH_HAS_PKEYS this will result in less generated code and
> a different return code: the three system calls will now always return
> -ENOSYS, using the cond_syscall mechanism.
>
> For architectures which have not wired up the system calls less
> unreachable code will be generated.
>
> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
This is fine with me. FWIW:
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm/pkeys: generate pkey system call code only if ARCH_HAS_PKEYS is selected
@ 2016-11-14 16:44 ` Dave Hansen
0 siblings, 0 replies; 4+ messages in thread
From: Dave Hansen @ 2016-11-14 16:44 UTC (permalink / raw)
To: Heiko Carstens, Andrew Morton
Cc: linux-arch, linux-kernel, linux-mm, Mark Rutland
On 11/14/2016 03:12 AM, Heiko Carstens wrote:
> Having code for the pkey_mprotect, pkey_alloc and pkey_free system
> calls makes only sense if ARCH_HAS_PKEYS is selected. If not selected
> these system calls will always return -ENOSPC or -EINVAL.
>
> To simplify things and have less code generate the pkey system call
> code only if ARCH_HAS_PKEYS is selected.
>
> For architectures which have already wired up the system calls, but do
> not select ARCH_HAS_PKEYS this will result in less generated code and
> a different return code: the three system calls will now always return
> -ENOSYS, using the cond_syscall mechanism.
>
> For architectures which have not wired up the system calls less
> unreachable code will be generated.
>
> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
This is fine with me. FWIW:
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply [flat|nested] 4+ messages in thread
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2016-11-14 11:12 [PATCH] mm/pkeys: generate pkey system call code only if ARCH_HAS_PKEYS is selected Heiko Carstens
2016-11-14 11:12 ` Heiko Carstens
2016-11-14 16:44 ` Dave Hansen
2016-11-14 16:44 ` Dave Hansen
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