diff options
Diffstat (limited to 'arch/arm64/kernel/entry.S')
| -rw-r--r-- | arch/arm64/kernel/entry.S | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index f29afcd8db37..7359293a812b 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -18,6 +18,7 @@ * along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#include <linux/arm-smccc.h> #include <linux/init.h> #include <linux/linkage.h> @@ -97,6 +98,25 @@ alternative_else_nop_endif add \dst, \dst, #(\sym - .entry.tramp.text) .endm + // This macro corrupts x0-x3. It is the caller's duty + // to save/restore them if required. + .macro apply_ssbd, state, targ, tmp1, tmp2 +#ifdef CONFIG_ARM64_SSBD +alternative_cb arm64_enable_wa2_handling + b \targ +alternative_cb_end + ldr_this_cpu \tmp2, arm64_ssbd_callback_required, \tmp1 + cbz \tmp2, \targ + ldr \tmp2, [tsk, #TI_FLAGS] + tbnz \tmp2, #TIF_SSBD, \targ + mov w0, #ARM_SMCCC_ARCH_WORKAROUND_2 + mov w1, #\state +alternative_cb arm64_update_smccc_conduit + nop // Patched to SMC/HVC #0 +alternative_cb_end +#endif + .endm + .macro kernel_entry, el, regsize = 64 .if \regsize == 32 mov w0, w0 // zero upper 32 bits of x0 @@ -123,6 +143,14 @@ alternative_else_nop_endif ldr x19, [tsk, #TSK_TI_FLAGS] // since we can unmask debug disable_step_tsk x19, x20 // exceptions when scheduling. + apply_ssbd 1, 1f, x22, x23 + +#ifdef CONFIG_ARM64_SSBD + ldp x0, x1, [sp, #16 * 0] + ldp x2, x3, [sp, #16 * 1] +#endif +1: + mov x29, xzr // fp pointed to user-space .else add x21, sp, #S_FRAME_SIZE @@ -251,6 +279,8 @@ alternative_if ARM64_WORKAROUND_845719 alternative_else_nop_endif #endif 3: + apply_ssbd 0, 5f, x0, x1 +5: .endif msr elr_el1, x21 // set up the return data |