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Subject[PATCH] proc: don't show nonexistent capabilities
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Without this patch it is really hard to interpret a bounding set,
if CAP_LAST_CAP is unknown for a current kernel.

Non-existant capabilities can not be deleted from a bounding set
with help of prctl.

E.g.: Here are two examples without/with this patch.
CapBnd: ffffffe0fdecffff
CapBnd: 00000000fdecffff

I suggest to hide non-existent capabilities. Here is two reasons.
* It's logically and easier for using.
* It helps to checkpoint-restore capabilities of tasks, because tasks
can be restored on another kernel, where CAP_LAST_CAP is bigger.

Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Vagin <avagin@openvz.org>
---
include/linux/capability.h | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/include/linux/capability.h b/include/linux/capability.h
index d10b7ed..1642778 100644
--- a/include/linux/capability.h
+++ b/include/linux/capability.h
@@ -420,7 +420,8 @@ extern const kernel_cap_t __cap_init_eff_set;
#else /* HAND-CODED capability initializers */

# define CAP_EMPTY_SET ((kernel_cap_t){{ 0, 0 }})
-# define CAP_FULL_SET ((kernel_cap_t){{ ~0, ~0 }})
+# define CAP_FULL_SET ((kernel_cap_t){{ ~0, \
+ CAP_TO_MASK(CAP_LAST_CAP + 1) - 1 } })
# define CAP_FS_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \
| CAP_TO_MASK(CAP_LINUX_IMMUTABLE), \
CAP_FS_MASK_B1 } })
--
1.7.1


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