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| author | Victor L. Do Nascimento <victor.donascimento@arm.com> | 2023-01-10 14:02:08 +0000 |
|---|---|---|
| committer | Richard Earnshaw <rearnsha@arm.com> | 2023-01-10 16:47:02 +0000 |
| commit | 31e5ce10db46bf8c15d78b2546553db45eb33141 (patch) | |
| tree | 08194bb7fa154a0ec7aae706a677bbdd31a40480 /newlib | |
| parent | adc36ede1137a0c792e0281cef01e7750f866ac5 (diff) | |
| download | newlib-31e5ce10db46bf8c15d78b2546553db45eb33141.zip newlib-31e5ce10db46bf8c15d78b2546553db45eb33141.tar.gz newlib-31e5ce10db46bf8c15d78b2546553db45eb33141.tar.bz2 | |
newlib: libc: setjmp M-profile PACBTI-enablement
Add function prologue/epilogue to conditionally add BTI landing pads
and/or PAC code generation & authentication instructions depending on
compilation flags. Save the PAC value in the jump buffer so that
longjmp can only return to the authenticated location.
Diffstat (limited to 'newlib')
| -rw-r--r-- | newlib/libc/machine/arm/setjmp.S | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/newlib/libc/machine/arm/setjmp.S b/newlib/libc/machine/arm/setjmp.S index d814afe..5213c06 100644 --- a/newlib/libc/machine/arm/setjmp.S +++ b/newlib/libc/machine/arm/setjmp.S @@ -22,6 +22,11 @@ #define SIZE(x) #endif +/* Jump buffer allocation sizes. */ +#define JUMPBUF_CORE_REGS_SIZE (10 * 4) +#define JUMPBUF_FP_REGS_SIZE (8 * 8) +#define JUMPBUF_PAC (JUMPBUF_CORE_REGS_SIZE + JUMPBUF_FP_REGS_SIZE + 0) + /* Arm/Thumb interworking support: The interworking scheme expects functions to use a BX instruction @@ -155,6 +160,8 @@ SYM (.arm_start_of.\name): .align 2 MODE .globl SYM (\name) + .fnstart + .cfi_startproc TYPE (\name) SYM (\name): PROLOGUE \name @@ -162,6 +169,8 @@ SYM (\name): .macro FUNC_END name RET + .cfi_endproc + .fnend SIZE (\name) .endm @@ -171,6 +180,21 @@ SYM (\name): FUNC_START setjmp +#if __ARM_FEATURE_PAC_DEFAULT +# if __ARM_FEATURE_BTI_DEFAULT + pacbti ip, lr, sp +# else + pac ip, lr, sp +# endif /* __ARM_FEATURE_BTI_DEFAULT */ + mov r3, ip + str r3, [r0, #JUMPBUF_PAC] + .cfi_register 143, 12 +#else +# if __ARM_FEATURE_BTI_DEFAULT + bti +# endif /* __ARM_FEATURE_BTI_DEFAULT */ +#endif /* __ARM_FEATURE_PAC_DEFAULT */ + /* Save all the callee-preserved registers into the jump buffer. */ #ifdef __thumb2__ mov ip, sp @@ -184,6 +208,10 @@ SYM (\name): /* When setting up the jump buffer return 0. */ mov r0, #0 +#if __ARM_FEATURE_PAC_DEFAULT + mov ip, r3 + aut ip, lr, sp +#endif /* __ARM_FEATURE_PAC_DEFAULT */ FUNC_END setjmp @@ -193,6 +221,16 @@ SYM (\name): FUNC_START longjmp +#if __ARM_FEATURE_BTI_DEFAULT + bti +#endif /* __ARM_FEATURE_BTI_DEFAULT */ + +#if __ARM_FEATURE_PAC_DEFAULT + /* Keep original jmpbuf address for retrieving pac-code + for authentication. */ + mov r2, r0 +#endif /* __ARM_FEATURE_PAC_DEFAULT */ + /* If we have stack extension code it ought to be handled here. */ /* Restore the registers, retrieving the state when setjmp() was called. */ @@ -212,5 +250,10 @@ SYM (\name): it eq moveq r0, #1 +#if __ARM_FEATURE_PAC_DEFAULT + ldr ip, [r2, #JUMPBUF_PAC] + aut ip, lr, sp +#endif /* __ARM_FEATURE_PAC_DEFAULT */ + FUNC_END longjmp #endif |