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| author |   Catalin Marinas <catalin.marinas@arm.com> | 2019-07-23 19:58:39 +0200 |
|---|---|---|
| committer |   Will Deacon <will@kernel.org> | 2019-08-06 18:08:45 +0100 |
| commit | 63f0c60379650d82250f22e4cf4137ef3dc4f43d (patch) | |
| tree | af76cdc5d0eeca023d86c43664d073af25d63546 /arch/arm64/include/asm/thread_info.h | |
| parent | arm64: untag user pointers in access_ok and __uaccess_mask_ptr (diff) | |
| download | linux-dev-63f0c60379650d82250f22e4cf4137ef3dc4f43d.tar.xz linux-dev-63f0c60379650d82250f22e4cf4137ef3dc4f43d.zip | |
arm64: Introduce prctl() options to control the tagged user addresses ABI
It is not desirable to relax the ABI to allow tagged user addresses into
the kernel indiscriminately. This patch introduces a prctl() interface
for enabling or disabling the tagged ABI with a global sysctl control
for preventing applications from enabling the relaxed ABI (meant for
testing user-space prctl() return error checking without reconfiguring
the kernel). The ABI properties are inherited by threads of the same
application and fork()'ed children but cleared on execve(). A Kconfig
option allows the overall disabling of the relaxed ABI.
The PR_SET_TAGGED_ADDR_CTRL will be expanded in the future to handle
MTE-specific settings like imprecise vs precise exceptions.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include/asm/thread_info.h')
| -rw-r--r-- | arch/arm64/include/asm/thread_info.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index 180b34ec5965..012238d8e58d 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -90,6 +90,7 @@ void arch_release_task_struct(struct task_struct *tsk); #define TIF_SVE 23 /* Scalable Vector Extension in use */ #define TIF_SVE_VL_INHERIT 24 /* Inherit sve_vl_onexec across exec */ #define TIF_SSBD 25 /* Wants SSB mitigation */ +#define TIF_TAGGED_ADDR 26 /* Allow tagged user addresses */ #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) |