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Diffstat (limited to 'string/arm/asmdefs.h')
| -rw-r--r-- | string/arm/asmdefs.h | 477 |
1 files changed, 477 insertions, 0 deletions
diff --git a/string/arm/asmdefs.h b/string/arm/asmdefs.h new file mode 100644 index 0000000..e311888 --- /dev/null +++ b/string/arm/asmdefs.h @@ -0,0 +1,477 @@ +/* + * Macros for asm code. Arm version. + * + * Copyright (c) 2019-2022, Arm Limited. + * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception + */ + +#ifndef _ASMDEFS_H +#define _ASMDEFS_H + +/* Check whether leaf function PAC signing has been requested in the + -mbranch-protect compile-time option. */ +#define LEAF_PROTECT_BIT 2 + +#ifdef __ARM_FEATURE_PAC_DEFAULT +# define HAVE_PAC_LEAF \ + ((__ARM_FEATURE_PAC_DEFAULT & (1 << LEAF_PROTECT_BIT)) && 1) +#else +# define HAVE_PAC_LEAF 0 +#endif + +/* Provide default parameters for PAC-code handling in leaf-functions. */ +#if HAVE_PAC_LEAF +# ifndef PAC_LEAF_PUSH_IP +# define PAC_LEAF_PUSH_IP 1 +# endif +#else /* !HAVE_PAC_LEAF */ +# undef PAC_LEAF_PUSH_IP +# define PAC_LEAF_PUSH_IP 0 +#endif /* HAVE_PAC_LEAF */ + +#define STACK_ALIGN_ENFORCE 0 + +/****************************************************************************** +* Implementation of the prologue and epilogue assembler macros and their +* associated helper functions. +* +* These functions add support for the following: +* +* - M-profile branch target identification (BTI) landing-pads when compiled +* with `-mbranch-protection=bti'. +* - PAC-signing and verification instructions, depending on hardware support +* and whether the PAC-signing of leaf functions has been requested via the +* `-mbranch-protection=pac-ret+leaf' compiler argument. +* - 8-byte stack alignment preservation at function entry, defaulting to the +* value of STACK_ALIGN_ENFORCE. +* +* Notes: +* - Prologue stack alignment is implemented by detecting a push with an odd +* number of registers and prepending a dummy register to the list. +* - If alignment is attempted on a list containing r0, compilation will result +* in an error. +* - If alignment is attempted in a list containing r1, r0 will be prepended to +* the register list and r0 will be restored prior to function return. for +* functions with non-void return types, this will result in the corruption of +* the result register. +* - Stack alignment is enforced via the following helper macro call-chain: +* +* {prologue|epilogue} ->_align8 -> _preprocess_reglist -> +* _preprocess_reglist1 -> {_prologue|_epilogue} +* +* - Debug CFI directives are automatically added to prologues and epilogues, +* assisted by `cfisavelist' and `cfirestorelist', respectively. +* +* Arguments: +* prologue +* -------- +* - first - If `last' specified, this serves as start of general-purpose +* register (GPR) range to push onto stack, otherwise represents +* single GPR to push onto stack. If omitted, no GPRs pushed +* onto stack at prologue. +* - last - If given, specifies inclusive upper-bound of GPR range. +* - push_ip - Determines whether IP register is to be pushed to stack at +* prologue. When pac-signing is requested, this holds the +* the pac-key. Either 1 or 0 to push or not push, respectively. +* Default behavior: Set to value of PAC_LEAF_PUSH_IP macro. +* - push_lr - Determines whether to push lr to the stack on function entry. +* Either 1 or 0 to push or not push, respectively. +* - align8 - Whether to enforce alignment. Either 1 or 0, with 1 requesting +* alignment. +* +* epilogue +* -------- +* The epilogue should be called passing the same arguments as those passed to +* the prologue to ensure the stack is not corrupted on function return. +* +* Usage examples: +* +* prologue push_ip=1 -> push {ip} +* epilogue push_ip=1, align8=1 -> pop {r2, ip} +* prologue push_ip=1, push_lr=1 -> push {ip, lr} +* epilogue 1 -> pop {r1} +* prologue 1, align8=1 -> push {r0, r1} +* epilogue 1, push_ip=1 -> pop {r1, ip} +* prologue 1, 4 -> push {r1-r4} +* epilogue 1, 4 push_ip=1 -> pop {r1-r4, ip} +* +******************************************************************************/ + +/* Emit .cfi_restore directives for a consecutive sequence of registers. */ + .macro cfirestorelist first, last + .cfi_restore \last + .if \last-\first + cfirestorelist \first, \last-1 + .endif + .endm + +/* Emit .cfi_offset directives for a consecutive sequence of registers. */ + .macro cfisavelist first, last, index=1 + .cfi_offset \last, -4*(\index) + .if \last-\first + cfisavelist \first, \last-1, \index+1 + .endif + .endm + +.macro _prologue first=-1, last=-1, push_ip=PAC_LEAF_PUSH_IP, push_lr=0 + .if \push_ip & 1 != \push_ip + .error "push_ip may be either 0 or 1" + .endif + .if \push_lr & 1 != \push_lr + .error "push_lr may be either 0 or 1" + .endif + .if \first != -1 + .if \last == -1 + /* Upper-bound not provided: Set upper = lower. */ + _prologue \first, \first, \push_ip, \push_lr + .exitm + .endif + .endif +#if HAVE_PAC_LEAF +# if __ARM_FEATURE_BTI_DEFAULT + pacbti ip, lr, sp +# else + pac ip, lr, sp +# endif /* __ARM_FEATURE_BTI_DEFAULT */ + .cfi_register 143, 12 +#else +# if __ARM_FEATURE_BTI_DEFAULT + bti +# endif /* __ARM_FEATURE_BTI_DEFAULT */ +#endif /* HAVE_PAC_LEAF */ + .if \first != -1 + .if \last != \first + .if \last >= 13 + .error "SP cannot be in the save list" + .endif + .if \push_ip + .if \push_lr + /* Case 1: push register range, ip and lr registers. */ + push {r\first-r\last, ip, lr} + .cfi_adjust_cfa_offset ((\last-\first)+3)*4 + .cfi_offset 14, -4 + .cfi_offset 143, -8 + cfisavelist \first, \last, 3 + .else // !\push_lr + /* Case 2: push register range and ip register. */ + push {r\first-r\last, ip} + .cfi_adjust_cfa_offset ((\last-\first)+2)*4 + .cfi_offset 143, -4 + cfisavelist \first, \last, 2 + .endif + .else // !\push_ip + .if \push_lr + /* Case 3: push register range and lr register. */ + push {r\first-r\last, lr} + .cfi_adjust_cfa_offset ((\last-\first)+2)*4 + .cfi_offset 14, -4 + cfisavelist \first, \last, 2 + .else // !\push_lr + /* Case 4: push register range. */ + push {r\first-r\last} + .cfi_adjust_cfa_offset ((\last-\first)+1)*4 + cfisavelist \first, \last, 1 + .endif + .endif + .else // \last == \first + .if \push_ip + .if \push_lr + /* Case 5: push single GP register plus ip and lr registers. */ + push {r\first, ip, lr} + .cfi_adjust_cfa_offset 12 + .cfi_offset 14, -4 + .cfi_offset 143, -8 + cfisavelist \first, \first, 3 + .else // !\push_lr + /* Case 6: push single GP register plus ip register. */ + push {r\first, ip} + .cfi_adjust_cfa_offset 8 + .cfi_offset 143, -4 + cfisavelist \first, \first, 2 + .endif + .else // !\push_ip + .if \push_lr + /* Case 7: push single GP register plus lr register. */ + push {r\first, lr} + .cfi_adjust_cfa_offset 8 + .cfi_offset 14, -4 + cfisavelist \first, \first, 2 + .else // !\push_lr + /* Case 8: push single GP register. */ + push {r\first} + .cfi_adjust_cfa_offset 4 + cfisavelist \first, \first, 1 + .endif + .endif + .endif + .else // \first == -1 + .if \push_ip + .if \push_lr + /* Case 9: push ip and lr registers. */ + push {ip, lr} + .cfi_adjust_cfa_offset 8 + .cfi_offset 14, -4 + .cfi_offset 143, -8 + .else // !\push_lr + /* Case 10: push ip register. */ + push {ip} + .cfi_adjust_cfa_offset 4 + .cfi_offset 143, -4 + .endif + .else // !\push_ip + .if \push_lr + /* Case 11: push lr register. */ + push {lr} + .cfi_adjust_cfa_offset 4 + .cfi_offset 14, -4 + .endif + .endif + .endif +.endm + +.macro _epilogue first=-1, last=-1, push_ip=PAC_LEAF_PUSH_IP, push_lr=0 + .if \push_ip & 1 != \push_ip + .error "push_ip may be either 0 or 1" + .endif + .if \push_lr & 1 != \push_lr + .error "push_lr may be either 0 or 1" + .endif + .if \first != -1 + .if \last == -1 + /* Upper-bound not provided: Set upper = lower. */ + _epilogue \first, \first, \push_ip, \push_lr + .exitm + .endif + .if \last != \first + .if \last >= 13 + .error "SP cannot be in the save list" + .endif + .if \push_ip + .if \push_lr + /* Case 1: pop register range, ip and lr registers. */ + pop {r\first-r\last, ip, lr} + .cfi_restore 14 + .cfi_register 143, 12 + cfirestorelist \first, \last + .else // !\push_lr + /* Case 2: pop register range and ip register. */ + pop {r\first-r\last, ip} + .cfi_register 143, 12 + cfirestorelist \first, \last + .endif + .else // !\push_ip + .if \push_lr + /* Case 3: pop register range and lr register. */ + pop {r\first-r\last, lr} + .cfi_restore 14 + cfirestorelist \first, \last + .else // !\push_lr + /* Case 4: pop register range. */ + pop {r\first-r\last} + cfirestorelist \first, \last + .endif + .endif + .else // \last == \first + .if \push_ip + .if \push_lr + /* Case 5: pop single GP register plus ip and lr registers. */ + pop {r\first, ip, lr} + .cfi_restore 14 + .cfi_register 143, 12 + cfirestorelist \first, \first + .else // !\push_lr + /* Case 6: pop single GP register plus ip register. */ + pop {r\first, ip} + .cfi_register 143, 12 + cfirestorelist \first, \first + .endif + .else // !\push_ip + .if \push_lr + /* Case 7: pop single GP register plus lr register. */ + pop {r\first, lr} + .cfi_restore 14 + cfirestorelist \first, \first + .else // !\push_lr + /* Case 8: pop single GP register. */ + pop {r\first} + cfirestorelist \first, \first + .endif + .endif + .endif + .else // \first == -1 + .if \push_ip + .if \push_lr + /* Case 9: pop ip and lr registers. */ + pop {ip, lr} + .cfi_restore 14 + .cfi_register 143, 12 + .else // !\push_lr + /* Case 10: pop ip register. */ + pop {ip} + .cfi_register 143, 12 + .endif + .else // !\push_ip + .if \push_lr + /* Case 11: pop lr register. */ + pop {lr} + .cfi_restore 14 + .endif + .endif + .endif +#if HAVE_PAC_LEAF + aut ip, lr, sp +#endif /* HAVE_PAC_LEAF */ + bx lr +.endm + +/* Clean up expressions in 'last'. */ +.macro _preprocess_reglist1 first:req, last:req, push_ip:req, push_lr:req, reglist_op:req + .if \last == 0 + \reglist_op \first, 0, \push_ip, \push_lr + .elseif \last == 1 + \reglist_op \first, 1, \push_ip, \push_lr + .elseif \last == 2 + \reglist_op \first, 2, \push_ip, \push_lr + .elseif \last == 3 + \reglist_op \first, 3, \push_ip, \push_lr + .elseif \last == 4 + \reglist_op \first, 4, \push_ip, \push_lr + .elseif \last == 5 + \reglist_op \first, 5, \push_ip, \push_lr + .elseif \last == 6 + \reglist_op \first, 6, \push_ip, \push_lr + .elseif \last == 7 + \reglist_op \first, 7, \push_ip, \push_lr + .elseif \last == 8 + \reglist_op \first, 8, \push_ip, \push_lr + .elseif \last == 9 + \reglist_op \first, 9, \push_ip, \push_lr + .elseif \last == 10 + \reglist_op \first, 10, \push_ip, \push_lr + .elseif \last == 11 + \reglist_op \first, 11, \push_ip, \push_lr + .else + .error "last (\last) out of range" + .endif +.endm + +/* Clean up expressions in 'first'. */ +.macro _preprocess_reglist first:req, last, push_ip=0, push_lr=0, reglist_op:req + .ifb \last + _preprocess_reglist \first \first \push_ip \push_lr + .else + .if \first > \last + .error "last (\last) must be at least as great as first (\first)" + .endif + .if \first == 0 + _preprocess_reglist1 0, \last, \push_ip, \push_lr, \reglist_op + .elseif \first == 1 + _preprocess_reglist1 1, \last, \push_ip, \push_lr, \reglist_op + .elseif \first == 2 + _preprocess_reglist1 2, \last, \push_ip, \push_lr, \reglist_op + .elseif \first == 3 + _preprocess_reglist1 3, \last, \push_ip, \push_lr, \reglist_op + .elseif \first == 4 + _preprocess_reglist1 4, \last, \push_ip, \push_lr, \reglist_op + .elseif \first == 5 + _preprocess_reglist1 5, \last, \push_ip, \push_lr, \reglist_op + .elseif \first == 6 + _preprocess_reglist1 6, \last, \push_ip, \push_lr, \reglist_op + .elseif \first == 7 + _preprocess_reglist1 7, \last, \push_ip, \push_lr, \reglist_op + .elseif \first == 8 + _preprocess_reglist1 8, \last, \push_ip, \push_lr, \reglist_op + .elseif \first == 9 + _preprocess_reglist1 9, \last, \push_ip, \push_lr, \reglist_op + .elseif \first == 10 + _preprocess_reglist1 10, \last, \push_ip, \push_lr, \reglist_op + .elseif \first == 11 + _preprocess_reglist1 11, \last, \push_ip, \push_lr, \reglist_op + .else + .error "first (\first) out of range" + .endif + .endif +.endm + +.macro _align8 first, last, push_ip=0, push_lr=0, reglist_op=_prologue + .ifb \first + .ifnb \last + .error "can't have last (\last) without specifying first" + .else // \last not blank + .if ((\push_ip + \push_lr) % 2) == 0 + \reglist_op first=-1, last=-1, push_ip=\push_ip, push_lr=\push_lr + .exitm + .else // ((\push_ip + \push_lr) % 2) odd + _align8 2, 2, \push_ip, \push_lr, \reglist_op + .exitm + .endif // ((\push_ip + \push_lr) % 2) == 0 + .endif // .ifnb \last + .endif // .ifb \first + + .ifb \last + _align8 \first, \first, \push_ip, \push_lr, \reglist_op + .else + .if \push_ip & 1 <> \push_ip + .error "push_ip may be 0 or 1" + .endif + .if \push_lr & 1 <> \push_lr + .error "push_lr may be 0 or 1" + .endif + .ifeq (\last - \first + \push_ip + \push_lr) % 2 + .if \first == 0 + .error "Alignment required and first register is r0" + .exitm + .endif + _preprocess_reglist \first-1, \last, \push_ip, \push_lr, \reglist_op + .else + _preprocess_reglist \first \last, \push_ip, \push_lr, \reglist_op + .endif + .endif +.endm + +.macro prologue first, last, push_ip=PAC_LEAF_PUSH_IP, push_lr=0, align8=STACK_ALIGN_ENFORCE + .if \align8 + _align8 \first, \last, \push_ip, \push_lr, _prologue + .else + _prologue first=\first, last=\last, push_ip=\push_ip, push_lr=\push_lr + .endif +.endm + +.macro epilogue first, last, push_ip=PAC_LEAF_PUSH_IP, push_lr=0, align8=STACK_ALIGN_ENFORCE + .if \align8 + _align8 \first, \last, \push_ip, \push_lr, reglist_op=_epilogue + .else + _epilogue first=\first, last=\last, push_ip=\push_ip, push_lr=\push_lr + .endif +.endm + +#define ENTRY_ALIGN(name, alignment) \ + .global name; \ + .type name,%function; \ + .align alignment; \ + name: \ + .fnstart; \ + .cfi_startproc; + +#define ENTRY(name) ENTRY_ALIGN(name, 6) + +#define ENTRY_ALIAS(name) \ + .global name; \ + .type name,%function; \ + name: + +#if defined (IS_LEAF) +# define END_UNWIND .cantunwind; +#else +# define END_UNWIND +#endif + +#define END(name) \ + .cfi_endproc; \ + END_UNWIND \ + .fnend; \ + .size name, .-name; + +#define L(l) .L ## l + +#endif |