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authorCatalin Marinas <catalin.marinas@arm.com>2019-07-23 19:58:39 +0200
committerWill Deacon <will@kernel.org>2019-08-06 18:08:45 +0100
commit63f0c60379650d82250f22e4cf4137ef3dc4f43d (patch)
treeaf76cdc5d0eeca023d86c43664d073af25d63546 /arch/arm64/include/asm/processor.h
parent2b835e24b5c6f9c633ff51973581ee7ca7b3e8ec (diff)
downloadlinux-63f0c60379650d82250f22e4cf4137ef3dc4f43d.tar.bz2
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/processor.h')
-rw-r--r--arch/arm64/include/asm/processor.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index 844e2964b0f5..28eed40ffc12 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -306,6 +306,14 @@ extern void __init minsigstksz_setup(void);
/* PR_PAC_RESET_KEYS prctl */
#define PAC_RESET_KEYS(tsk, arg) ptrauth_prctl_reset_keys(tsk, arg)
+#ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
+/* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */
+long set_tagged_addr_ctrl(unsigned long arg);
+long get_tagged_addr_ctrl(void);
+#define SET_TAGGED_ADDR_CTRL(arg) set_tagged_addr_ctrl(arg)
+#define GET_TAGGED_ADDR_CTRL() get_tagged_addr_ctrl()
+#endif
+
/*
* For CONFIG_GCC_PLUGIN_STACKLEAK
*