libsanitizer/sanitizer_common/sanitizer_common_interceptors_vfork_arm.inc.S

   1 #if defined(__arm__) && defined(__linux__)
   2
   3 #include "sanitizer_common/sanitizer_asm.h"
   4
   5 ASM_HIDDEN(COMMON_INTERCEPTOR_SPILL_AREA)
   6
   7 .comm _ZN14__interception10real_vforkE,4,4
   8 .globl ASM_WRAPPER_NAME(vfork)
   9 ASM_TYPE_FUNCTION(ASM_WRAPPER_NAME(vfork))
  10 ASM_WRAPPER_NAME(vfork):
  11         // Save LR in the off-stack spill area.
  12         push    {r4, lr}
  13         bl      COMMON_INTERCEPTOR_SPILL_AREA
  14         pop     {r4, lr}
  15         str     lr, [r0]
  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         ldr     r0, .LCPI0_0
  20 .LPC0_0:
  21         ldr     r0, [pc, r0]
  22         mov     lr, pc
  23         bx      r0
  24
  25         push    {r0, r4}
  26         cmp     r0, #0
  27         beq     .L_exit
  28
  29         // r0 != 0 => parent process. Clear stack shadow.
  30         add     r0, sp, #8
  31         bl      COMMON_INTERCEPTOR_HANDLE_VFORK
  32
  33 .L_exit:
  34         // Restore LR.
  35         bl      COMMON_INTERCEPTOR_SPILL_AREA
  36         ldr     lr, [r0]
  37         pop     {r0, r4}
  38
  39         mov     pc, lr
  40
  41 .LCPI0_0:
  42         .long   _ZN14__interception10real_vforkE - (.LPC0_0+8)
  43
  44 ASM_SIZE(vfork)
  45
  46 .weak vfork
  47 .set vfork, ASM_WRAPPER_NAME(vfork)
  48
  49 #endif