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| author | Victor Do Nascimento <Victor.DoNascimento@arm.com> | 2022-06-22 15:04:08 +0100 |
|---|---|---|
| committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2022-06-22 15:05:08 +0100 |
| commit | fa00b1bde8444483823723958fed97ae91775437 (patch) | |
| tree | 312796008cb87bc221dfa59610d1677e177eb713 | |
| parent | 7b5e5cb19d5f2d1c09d6196a4acfbd8a943e1f36 (diff) | |
| download | arm-optimized-routines-fa00b1bde8444483823723958fed97ae91775437.tar.gz | |
string: Add M-profile PACBTI implementation of strcmp
Ensure BTI indirect branch landing pads (BTI) and pointer authentication
code genetaion (PAC) and verification instructions (BXAUT) are
conditionally added to assembly when branch protection is requested.
NOTE: ENTRY_ALIGN() Macro factored out as .fnstart & .cfi_startproc
directives needed to be moved to prior to L(fastpath_exit)
| -rw-r--r-- | string/arm/strcmp.S | 45 |
1 files changed, 35 insertions, 10 deletions
diff --git a/string/arm/strcmp.S b/string/arm/strcmp.S index 622efb9..db96cc0 100644 --- a/string/arm/strcmp.S +++ b/string/arm/strcmp.S @@ -13,6 +13,7 @@ the compares. */ #include "../asmdefs.h" +#include "../pacbti.h" /* Build Options: STRCMP_NO_PRECHECK: Don't run a quick pre-check of the first @@ -98,8 +99,9 @@ ldrd r4, r5, [sp], #16 .cfi_restore 4 .cfi_restore 5 + .cfi_adjust_cfa_offset -16 sub result, result, r1, lsr #24 - bx lr + pacbti_epilogue #else /* To use the big-endian trick we'd have to reverse all three words. that's slower than this approach. */ @@ -119,21 +121,28 @@ ldrd r4, r5, [sp], #16 .cfi_restore 4 .cfi_restore 5 + .cfi_adjust_cfa_offset -16 sub result, result, r1 - bx lr + pacbti_epilogue #endif .endm .p2align 5 L(strcmp_start_addr): + .fnstart + .cfi_startproc #if STRCMP_NO_PRECHECK == 0 L(fastpath_exit): sub r0, r2, r3 - bx lr + pacbti_epilogue nop #endif -ENTRY_ALIGN (__strcmp_arm, 0) + .global __strcmp_arm + .type __strcmp_arm,%function + .align 0 +__strcmp_arm: + pacbti_prologue #if STRCMP_NO_PRECHECK == 0 ldrb r2, [src1] ldrb r3, [src2] @@ -143,13 +152,25 @@ ENTRY_ALIGN (__strcmp_arm, 0) bne L(fastpath_exit) #endif strd r4, r5, [sp, #-16]! - .cfi_def_cfa_offset 16 + .save {r4, r5} + .cfi_adjust_cfa_offset 16 +#ifdef __ARM_FEATURE_PAC_DEFAULT + .cfi_offset 4, -20 + .cfi_offset 5, -16 +#else .cfi_offset 4, -16 .cfi_offset 5, -12 +#endif /* __ARM_FEATURE_PAC_DEFAULT */ orr tmp1, src1, src2 strd r6, r7, [sp, #8] + .save {r6, r7} +#ifdef __ARM_FEATURE_PAC_DEFAULT + .cfi_offset 6, -12 + .cfi_offset 7, -8 +#else .cfi_offset 6, -8 .cfi_offset 7, -4 +#endif /* __ARM_FEATURE_PAC_DEFAULT */ mvn const_m1, #0 lsl r2, tmp1, #29 cbz r2, L(loop_aligned8) @@ -318,7 +339,9 @@ L(misaligned_exit): mov result, tmp1 ldr r4, [sp], #16 .cfi_restore 4 - bx lr + .cfi_adjust_cfa_offset -16 + + pacbti_epilogue #if STRCMP_NO_PRECHECK == 0 L(aligned_m1): @@ -368,9 +391,9 @@ L(overlap3): /* R6/7 Not used in this sequence. */ .cfi_restore 6 .cfi_restore 7 + .cfi_adjust_cfa_offset -16 neg result, result - bx lr - + pacbti_epilogue 6: .cfi_restore_state S2LO data1, data1, #24 @@ -445,7 +468,8 @@ L(strcmp_done_equal): /* R6/7 not used in this sequence. */ .cfi_restore 6 .cfi_restore 7 - bx lr + .cfi_adjust_cfa_offset -16 + pacbti_epilogue L(strcmp_tail): .cfi_restore_state @@ -467,8 +491,9 @@ L(strcmp_tail): /* R6/7 not used in this sequence. */ .cfi_restore 6 .cfi_restore 7 + .cfi_adjust_cfa_offset -16 sub result, result, data2, lsr #24 - bx lr + pacbti_epilogue END (__strcmp_arm) |