| Message ID | 20191211154206.46260-4-broonie@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | arm64: ARMv8.5-A: Branch Target Identification support | expand |
On Wed, Dec 11, 2019 at 03:41:57PM +0000, Mark Brown wrote: > From: Dave Martin <Dave.Martin@arm.com> > > The asm-generic mman definitions are used by a few architectures > that also define an arch-specific PROT flag with value 0x10. This > currently applies to sparc and powerpc, and arm64 will soon join > in. > > To help future maintainers, document the use of this flag in the > asm-generic header too. > > Signed-off-by: Dave Martin <Dave.Martin@arm.com> > Signed-off-by: Mark Brown <broonie@kernel.org> > --- > include/uapi/asm-generic/mman-common.h | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h > index c160a5354eb6..81442d2aaecb 100644 > --- a/include/uapi/asm-generic/mman-common.h > +++ b/include/uapi/asm-generic/mman-common.h > @@ -11,6 +11,7 @@ > #define PROT_WRITE 0x2 /* page can be written */ > #define PROT_EXEC 0x4 /* page can be executed */ > #define PROT_SEM 0x8 /* page may be used for atomic ops */ > + /* 0x10 reserved for arch-specific use */ > #define PROT_NONE 0x0 /* page can not be accessed */ > #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 */ Since the BTI will likely be merged before the MTE series, please consider reserving 0x20 as well. The updated patch, acked by Arnd: https://lore.kernel.org/linux-arm-kernel/20191211184027.20130-2-catalin.marinas@arm.com/ -- Catalin
On Thu, Dec 12, 2019 at 10:48:32AM +0000, Catalin Marinas wrote: > On Wed, Dec 11, 2019 at 03:41:57PM +0000, Mark Brown wrote: > > #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 */ > Since the BTI will likely be merged before the MTE series, please > consider reserving 0x20 as well. The updated patch, acked by Arnd: Sure.
diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h index c160a5354eb6..81442d2aaecb 100644 --- a/include/uapi/asm-generic/mman-common.h +++ b/include/uapi/asm-generic/mman-common.h @@ -11,6 +11,7 @@ #define PROT_WRITE 0x2 /* page can be written */ #define PROT_EXEC 0x4 /* page can be executed */ #define PROT_SEM 0x8 /* page may be used for atomic ops */ + /* 0x10 reserved for arch-specific use */ #define PROT_NONE 0x0 /* page can not be accessed */ #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 */