This whitelists the FPU register state portion of the thread_struct for
copying to userspace, instead of the default entire structure.
Cc: Catalin Marinas <catalin.mari...@arm.com>
Cc: Will Deacon <will.dea...@arm.com>
Cc: Christian Borntraeger <borntrae...@de.ibm.com>
Cc: Ingo Molnar <mi...@kernel.org>
Cc: James Morse <james.mo...@arm.com>
Cc: "Peter Zijlstra (Intel)" <pet...@infradead.org>
Cc: Dave Martin <dave.mar...@arm.com>
Cc: zijun_hu <zijun...@htc.com>
Cc: linux-arm-ker...@lists.infradead.org
Signed-off-by: Kees Cook <keesc...@chromium.org>
---
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/processor.h | 8 ++++++++
2 files changed, 9 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 0df64a6a56d4..e190f9901aef 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -73,6 +73,7 @@ config ARM64
select HAVE_ARCH_MMAP_RND_BITS
select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
select HAVE_ARCH_SECCOMP_FILTER
+ select HAVE_ARCH_THREAD_STRUCT_WHITELIST
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_TRANSPARENT_HUGEPAGE
select HAVE_ARCH_VMAP_STACK
diff --git a/arch/arm64/include/asm/processor.h
b/arch/arm64/include/asm/processor.h
index 29adab8138c3..759c4d90ac7f 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -90,6 +90,14 @@ struct thread_struct {
struct debug_info debug; /* debugging */
};
+/* Whitelist the fpsimd_state for copying to userspace. */
+static inline void arch_thread_struct_whitelist(unsigned long *offset,
+ unsigned long *size)
+{
+ *offset = offsetof(struct thread_struct, fpsimd_state);
+ *size = sizeof(struct fpsimd_state);
+}
+
#ifdef CONFIG_COMPAT
#define task_user_tls(t) \
({ \
--
2.7.4
