arm_aarch64_common.h

/*!
 *@page License
 *
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#ifndef CODEC_COMMON_ARM64_ARM_AARCH64_COMMON_H_
#define CODEC_COMMON_ARM64_ARM_AARCH64_COMMON_H_

/*
 ; Support macros for
 ;   - Armv8.3-A Pointer Authentication and
 ;   - Armv8.5-A Branch Target Identification
 ; Further documentation can be found at:
 ;  - https://developer.arm.com/documentation/101028/0012/5--Feature-test-macros
 ;
 ; Since openh264 aarch64 assembly code provides functions with no storage of the
 ; LR(x30) on the stack, PAC is not needed as modification of the LR value would
 ; require modification of x30 and not memory. Additionally, no indirect control
 ; flow changes are performed, so bti j instructions are not needed. Thus, just
 ; mark the entry points with bti c landing pads and the ELF files as supporting
 ; BTI and PAC.
 */
#if defined(__ARM_FEATURE_BTI_DEFAULT) && __ARM_FEATURE_BTI_DEFAULT == 1
  /* BTI is enabled */
  #define BTI_C hint 34
  #define GNU_PROPERTY_AARCH64_BTI 0x1 /* Property for notes section in ELF */
#else
  /* BTI is NOT enabled */
  #define BTI_C
  #define GNU_PROPERTY_AARCH64_BTI 0
#endif

#if defined(__ARM_FEATURE_PAC_DEFAULT)
  /* PAC is enabled */
  #define GNU_PROPERTY_AARCH64_POINTER_AUTH 0x2 /* Property for notes section in ELF */
#else
  /* PAC is not enabled */
  #define GNU_PROPERTY_AARCH64_POINTER_AUTH 0
#endif

/* Add the notes section to ELF only */
#if defined(__ELF__)
  .pushsection .note.gnu.property, "a";
  .balign 8;
  .long 4;
  .long 0x10;
  .long 0x5;
  .asciz "GNU";
  .long 0xc0000000; /* GNU_PROPERTY_AARCH64_FEATURE_1_AND */
  .long 4;
  .long(GNU_PROPERTY_AARCH64_POINTER_AUTH | GNU_PROPERTY_AARCH64_BTI);
  .long 0;
  .popsection;
#endif

#endif /* CODEC_COMMON_ARM64_ARM_AARCH64_COMMON_H_ */