Unverified Commit 13e47beb authored by Tong Tiangen's avatar Tong Tiangen Committed by Palmer Dabbelt
Browse files

riscv: Implement thread_struct whitelist for hardened usercopy 



This whitelists the FPU register state portion of the thread_struct for
copying to userspace, instead of the default entire struct.

Signed-off-by: default avatarTong Tiangen <tongtiangen@huawei.com>
Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent 67979e92

arch/riscv/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ config RISCV 
	select HAVE_ARCH_SECCOMP_FILTER

	select HAVE_ARCH_TRACEHOOK

	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU

	select HAVE_ARCH_THREAD_STRUCT_WHITELIST

	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT

	select HAVE_ASM_MODVERSIONS

	select HAVE_CONTEXT_TRACKING

arch/riscv/include/asm/processor.h

+8 −0
Original line number Diff line number Diff line
@@ -37,6 +37,14 @@ struct thread_struct { 
	unsigned long bad_cause;

};



/* Whitelist the fstate from the task_struct for hardened usercopy */

static inline void arch_thread_struct_whitelist(unsigned long *offset,

						unsigned long *size)

{

	*offset = offsetof(struct thread_struct, fstate);

	*size = sizeof_field(struct thread_struct, fstate);

}



#define INIT_THREAD {					\

	.sp = sizeof(init_stack) + (long)&init_stack,	\

}