arch/arm64/include/asm/scs.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_SCS_H
   3 #define _ASM_SCS_H
   4
   5 #ifdef __ASSEMBLY__
   6
   7 #include <asm/asm-offsets.h>
   8 #include <asm/sysreg.h>
   9
  10 #ifdef CONFIG_SHADOW_CALL_STACK
  11         scs_sp  .req    x18
  12
  13         .macro scs_load_current
  14         get_current_task scs_sp
  15         ldr     scs_sp, [scs_sp, #TSK_TI_SCS_SP]
  16         .endm
  17
  18         .macro scs_save tsk
  19         str     scs_sp, [\tsk, #TSK_TI_SCS_SP]
  20         .endm
  21 #else
  22         .macro scs_load_current
  23         .endm
  24
  25         .macro scs_save tsk
  26         .endm
  27 #endif /* CONFIG_SHADOW_CALL_STACK */
  28
  29
  30 #else
  31
  32 #include <linux/scs.h>
  33 #include <asm/cpufeature.h>
  34
  35 #ifdef CONFIG_UNWIND_PATCH_PAC_INTO_SCS
  36 static inline void dynamic_scs_init(void)
  37 {
  38         extern bool __pi_dynamic_scs_is_enabled;
  39
  40         if (__pi_dynamic_scs_is_enabled) {
  41                 pr_info("Enabling dynamic shadow call stack\n");
  42                 static_branch_enable(&dynamic_scs_enabled);
  43         }
  44 }
  45 #else
  46 static inline void dynamic_scs_init(void) {}
  47 #endif
  48
  49 int __pi_scs_patch(const u8 eh_frame[], int size);
  50 asmlinkage void __pi_scs_patch_vmlinux(void);
  51
  52 #endif /* __ASSEMBLY __ */
  53
  54 #endif /* _ASM_SCS_H */