From: Amit Daniel Kachhap amitdaniel.kachhap@arm.com
The PCuABI specification introduces limitations in expanding the capability permissions, notably through the mprotect() system call. This requires owning capabilities to be initially created with the maximum permissions that the memory mappings may possess in their lifetime.
Signed-off-by: Amit Daniel Kachhap amitdaniel.kachhap@arm.com Signed-off-by: Kevin Brodsky kevin.brodsky@arm.com --- include/uapi/asm-generic/mman-common.h | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h index 6ce1f1ceb432..e7ba511c2bad 100644 --- a/include/uapi/asm-generic/mman-common.h +++ b/include/uapi/asm-generic/mman-common.h @@ -17,6 +17,12 @@ #define PROT_GROWSDOWN 0x01000000 /* mprotect flag: extend change to start of growsdown vma */ #define PROT_GROWSUP 0x02000000 /* mprotect flag: extend change to end of growsup vma */
+/* PCuABI mapping and capability permissions */ +#define _PROT_MAX_SHIFT 16 +#define PROT_MAX(prot) ((prot) << _PROT_MAX_SHIFT) +#define PROT_EXTRACT(prot) ((prot) & (PROT_READ | PROT_WRITE | PROT_EXEC)) +#define PROT_MAX_EXTRACT(prot) (((prot) >> _PROT_MAX_SHIFT) & (PROT_READ | PROT_WRITE | PROT_EXEC)) + /* 0x01 - 0x03 are defined in linux/mman.h */ #define MAP_TYPE 0x0f /* Mask for type of mapping */ #define MAP_FIXED 0x10 /* Interpret addr exactly */