libsanitizer/sanitizer_common/sanitizer_common_interceptors_vfork_aarch64.inc.S

   1 #if defined(__aarch64__) && defined(__linux__)
   2
   3 #include "sanitizer_common/sanitizer_asm.h"
   4
   5 ASM_HIDDEN(COMMON_INTERCEPTOR_SPILL_AREA)
   6
   7 .comm _ZN14__interception10real_vforkE,8,8
   8 .globl ASM_WRAPPER_NAME(vfork)
   9 ASM_TYPE_FUNCTION(ASM_WRAPPER_NAME(vfork))
  10 ASM_WRAPPER_NAME(vfork):
  11         // Save x30 in the off-stack spill area.
  12         stp     xzr, x30, [sp, #-16]!
  13         bl      COMMON_INTERCEPTOR_SPILL_AREA
  14         ldp     xzr, x30, [sp], 16
  15         str     x30, [x0]
  16
  17         // Call real vfork. This may return twice. User code that runs between the first and the second return
  18         // may clobber the stack frame of the interceptor; that's why it does not have a frame.
  19         adrp    x0, _ZN14__interception10real_vforkE
  20         ldr     x0, [x0, :lo12:_ZN14__interception10real_vforkE]
  21         blr     x0
  22
  23         stp     x0, xzr, [sp, #-16]!
  24         cmp     x0, #0
  25         b.eq   .L_exit
  26
  27         // x0 != 0 => parent process. Clear stack shadow.
  28         add    x0, sp, #16
  29         bl     COMMON_INTERCEPTOR_HANDLE_VFORK
  30
  31 .L_exit:
  32         // Restore x30.
  33         bl     COMMON_INTERCEPTOR_SPILL_AREA
  34         ldr    x30, [x0]
  35         ldp    x0, xzr, [sp], 16
  36
  37         ret
  38 ASM_SIZE(vfork)
  39
  40 .weak vfork
  41 .set vfork, ASM_WRAPPER_NAME(vfork)
  42
  43 #endif