This patch adds support for {get,set,swap,make}context to the ARM
architecture. Files are imported from glibc.Signed-off-by: Timon ter Braak <[email protected]> Signed-off-by: Florian Fainelli <[email protected]> --- extra/Configs/Config.arm | 1 + libc/sysdeps/linux/arm/Makefile.arch | 5 +++ libc/sysdeps/linux/arm/getcontext.S | 80 +++++++++++++++++++++++++++++++++ libc/sysdeps/linux/arm/makecontext.c | 73 ++++++++++++++++++++++++++++++ libc/sysdeps/linux/arm/setcontext.S | 76 +++++++++++++++++++++++++++++++ libc/sysdeps/linux/arm/swapcontext.S | 63 ++++++++++++++++++++++++++ libc/sysdeps/linux/arm/ucontext_i.sym | 30 +++++++++++++ 7 files changed, 328 insertions(+) create mode 100644 libc/sysdeps/linux/arm/getcontext.S create mode 100644 libc/sysdeps/linux/arm/makecontext.c create mode 100644 libc/sysdeps/linux/arm/setcontext.S create mode 100644 libc/sysdeps/linux/arm/swapcontext.S create mode 100644 libc/sysdeps/linux/arm/ucontext_i.sym diff --git a/extra/Configs/Config.arm b/extra/Configs/Config.arm index 0bb2971..dc53643 100644 --- a/extra/Configs/Config.arm +++ b/extra/Configs/Config.arm @@ -11,6 +11,7 @@ config FORCE_OPTIONS_FOR_ARCH bool default y select ARCH_ANY_ENDIAN + select ARCH_HAS_UCONTEXT config CONFIG_ARM_EABI bool "Build for EABI" diff --git a/libc/sysdeps/linux/arm/Makefile.arch b/libc/sysdeps/linux/arm/Makefile.arch index 5fc3e54..36d988b 100644 --- a/libc/sysdeps/linux/arm/Makefile.arch +++ b/libc/sysdeps/linux/arm/Makefile.arch @@ -43,3 +43,8 @@ libc-static-y += $(ARCH_OUT)/aeabi_lcsts.o $(ARCH_OUT)/aeabi_math.o \ libc-nonshared-y += $(ARCH_OUT)/aeabi_lcsts.os $(ARCH_OUT)/aeabi_math.os \ $(ARCH_OUT)/aeabi_sighandlers.os $(ARCH_OUT)/aeabi_unwind_cpp_pr1.o endif + +ifeq ($(UCLIBC_HAS_CONTEXT_FUNCS),y) +CSRC += makecontext.c +SSRC += getcontext.S setcontext.S swapcontext.S +endif diff --git a/libc/sysdeps/linux/arm/getcontext.S b/libc/sysdeps/linux/arm/getcontext.S new file mode 100644 index 0000000..9aa241b --- /dev/null +++ b/libc/sysdeps/linux/arm/getcontext.S @@ -0,0 +1,80 @@ +/* Copyright (C) 2012 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + +#include "ucontext_i.h" + + .syntax unified + .text + +/* int getcontext (ucontext_t *ucp) */ + +ENTRY(__getcontext) + /* No need to save r0-r3, d0-d7, or d16-d31. */ + add r1, r0, #MCONTEXT_ARM_R4 + stmia r1, {r4-r11} + + /* Save R13 separately as Thumb can't STM it. */ + str r13, [r0, #MCONTEXT_ARM_SP] + str r14, [r0, #MCONTEXT_ARM_LR] + /* Return to LR */ + str r14, [r0, #MCONTEXT_ARM_PC] + /* Return zero */ + mov r2, #0 + str r2, [r0, #MCONTEXT_ARM_R0] + + /* Save ucontext_t * across the next call. */ + mov r4, r0 + + /* __sigprocmask(SIG_BLOCK, NULL, &(ucontext->uc_sigmask)) */ + mov r0, #SIG_BLOCK + mov r1, #0 + add r2, r4, #UCONTEXT_SIGMASK + bl PLTJMP(sigprocmask) + +#if defined __UCLIBC_HAS_FLOATS__ && ! defined __UCLIBC_HAS_SOFT_FLOAT__ +# ifdef __VFP_FP__ + /* Store the VFP registers. */ + /* Following instruction is fstmiax ip!, {d8-d15}. */ + stc p11, cr8, [r0], #64 + /* Store the floating-point status register. */ + /* Following instruction is fmrx r2, fpscr. */ + mrc p10, 7, r1, cr1, cr0, 0 + str r1, [r0], #4 +# endif +#endif +#ifdef __IWMMXT__ + /* Save the call-preserved iWMMXt registers. */ + /* Following instructions are wstrd wr10, [r0], #8 (etc.) */ + stcl p1, cr10, [r0], #8 + stcl p1, cr11, [r0], #8 + stcl p1, cr12, [r0], #8 + stcl p1, cr13, [r0], #8 + stcl p1, cr14, [r0], #8 + stcl p1, cr15, [r0], #8 +#endif + + /* Restore the clobbered R4 and LR. */ + ldr r14, [r4, #MCONTEXT_ARM_LR] + ldr r4, [r4, #MCONTEXT_ARM_R4] + + mov r0, #0 + DO_RET(r14) + +END(__getcontext) +weak_alias(__getcontext, getcontext) diff --git a/libc/sysdeps/linux/arm/makecontext.c b/libc/sysdeps/linux/arm/makecontext.c new file mode 100644 index 0000000..d6ae6f0 --- /dev/null +++ b/libc/sysdeps/linux/arm/makecontext.c @@ -0,0 +1,73 @@ +/* Copyright (C) 2012 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <stdarg.h> +#include <ucontext.h> + +/* Number of arguments that go in registers. */ +#define NREG_ARGS 4 + +/* Take a context previously prepared via getcontext() and set to + call func() with the given int only args. */ +void +__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...) +{ + extern void __startcontext (void); + unsigned long *funcstack; + va_list vl; + unsigned long *regptr; + unsigned int reg; + int misaligned; + + /* Start at the top of stack. */ + funcstack = (unsigned long *) (ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size); + + /* Ensure the stack stays eight byte aligned. */ + misaligned = ((unsigned long) funcstack & 4) != 0; + + if ((argc > NREG_ARGS) && (argc & 1) != 0) + misaligned = !misaligned; + + if (misaligned) + funcstack -= 1; + + va_start (vl, argc); + + /* Reserve space for the on-stack arguments. */ + if (argc > NREG_ARGS) + funcstack -= (argc - NREG_ARGS); + + ucp->uc_mcontext.arm_sp = (unsigned long) funcstack; + ucp->uc_mcontext.arm_pc = (unsigned long) func; + + /* Exit to startcontext() with the next context in R4 */ + ucp->uc_mcontext.arm_r4 = (unsigned long) ucp->uc_link; + ucp->uc_mcontext.arm_lr = (unsigned long) __startcontext; + + /* The first four arguments go into registers. */ + regptr = &(ucp->uc_mcontext.arm_r0); + + for (reg = 0; (reg < argc) && (reg < NREG_ARGS); reg++) + *regptr++ = va_arg (vl, unsigned long); + + /* And the remainder on the stack. */ + for (; reg < argc; reg++) + *funcstack++ = va_arg (vl, unsigned long); + + va_end (vl); +} +weak_alias (__makecontext, makecontext) diff --git a/libc/sysdeps/linux/arm/setcontext.S b/libc/sysdeps/linux/arm/setcontext.S new file mode 100644 index 0000000..a5c33a0 --- /dev/null +++ b/libc/sysdeps/linux/arm/setcontext.S @@ -0,0 +1,76 @@ +/* Copyright (C) 2012 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + +#include "ucontext_i.h" + + .syntax unified + .text + +/* int setcontext (const ucontext_t *ucp) */ + +ENTRY(__setcontext) + mov r4, r0 + +#if defined __UCLIBC_HAS_FLOATS__ && ! defined __UCLIBC_HAS_SOFT_FLOAT__ +# ifdef __VFP_FP__ + /* Following instruction is vldmia r0!, {d8-d15}. */ + ldc p11, cr8, [r0], #64 + /* Restore the floating-point status register. */ + ldr r1, [r0], #4 + /* Following instruction is fmxr fpscr, r1. */ + mcr p10, 7, r1, cr1, cr0, 0 +# endif +#endif + +#ifdef __IWMMXT__ + /* Restore the call-preserved iWMMXt registers. */ + /* Following instructions are wldrd wr10, [r0], #8 (etc.) */ + ldcl p1, cr10, [r0], #8 + ldcl p1, cr11, [r0], #8 + ldcl p1, cr12, [r0], #8 + ldcl p1, cr13, [r0], #8 + ldcl p1, cr14, [r0], #8 + ldcl p1, cr15, [r0], #8 +#endif + + /* Now bring back the signal status. */ + mov r0, #SIG_SETMASK + add r1, r4, #UCONTEXT_SIGMASK + mov r2, #0 + bl PLTJMP(sigprocmask) + + /* Loading r0-r3 makes makecontext easier. */ + add r14, r4, #MCONTEXT_ARM_R0 + ldmia r14, {r0-r11} + ldr r13, [r14, #(MCONTEXT_ARM_SP - MCONTEXT_ARM_R0)] + add r14, r14, #(MCONTEXT_ARM_LR - MCONTEXT_ARM_R0) + ldmia r14, {r14, pc} + +END(setcontext) +weak_alias(__setcontext, setcontext) + + /* Called when a makecontext() context returns. Start the + context in R4 or fall through to exit(). */ +ENTRY(__startcontext) + movs r0, r4 + bne PLTJMP(__setcontext) + + @ New context was 0 - exit + b PLTJMP(_exit) +END(__startcontext) diff --git a/libc/sysdeps/linux/arm/swapcontext.S b/libc/sysdeps/linux/arm/swapcontext.S new file mode 100644 index 0000000..09492d0 --- /dev/null +++ b/libc/sysdeps/linux/arm/swapcontext.S @@ -0,0 +1,63 @@ +/* Copyright (C) 2012 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + +#include "ucontext_i.h" + + .syntax unified + .text + +/* int swapcontext (ucontext_t *oucp, const ucontext_t *ucp) */ + +ENTRY(swapcontext) + + /* Have getcontext() do most of the work then fix up + LR afterwards. Save R3 to keep the stack aligned. */ + push {r0,r1,r3,r14} + cfi_adjust_cfa_offset (16) + cfi_rel_offset (r0,0) + cfi_rel_offset (r1,4) + cfi_rel_offset (r3,8) + cfi_rel_offset (r14,12) + + bl __getcontext + mov r4, r0 + + pop {r0,r1,r3,r14} + cfi_adjust_cfa_offset (-16) + cfi_restore (r0) + cfi_restore (r1) + cfi_restore (r3) + cfi_restore (r14) + + /* Exit if getcontext() failed. */ + cmp r4, #0 + itt ne + movne r0, r4 + RETINSTR(ne, r14) + + /* Fix up LR and the PC. */ + str r13,[r0, #MCONTEXT_ARM_SP] + str r14,[r0, #MCONTEXT_ARM_LR] + str r14,[r0, #MCONTEXT_ARM_PC] + + /* And swap using swapcontext(). */ + mov r0, r1 + b __setcontext + +END(swapcontext) diff --git a/libc/sysdeps/linux/arm/ucontext_i.sym b/libc/sysdeps/linux/arm/ucontext_i.sym new file mode 100644 index 0000000..9650322 --- /dev/null +++ b/libc/sysdeps/linux/arm/ucontext_i.sym @@ -0,0 +1,30 @@ +#include <inttypes.h> +#include <signal.h> +#include <stddef.h> +#include <sys/ucontext.h> + +SIG_BLOCK +SIG_SETMASK + +-- Offsets of the fields in the ucontext_t structure. +#define ucontext(member) offsetof (ucontext_t, member) +#define mcontext(member) ucontext (uc_mcontext.member) + +UCONTEXT_FLAGS ucontext (uc_flags) +UCONTEXT_LINK ucontext (uc_link) +UCONTEXT_STACK ucontext (uc_stack) +UCONTEXT_MCONTEXT ucontext (uc_mcontext) +UCONTEXT_SIGMASK ucontext (uc_sigmask) + +UCONTEXT_REGSPACE ucontext (uc_regspace) + +MCONTEXT_TRAP_NO mcontext (trap_no) +MCONTEXT_ERROR_CODE mcontext (error_code) +MCONTEXT_OLDMASK mcontext (oldmask) +MCONTEXT_ARM_R0 mcontext (arm_r0) +MCONTEXT_ARM_R4 mcontext (arm_r4) +MCONTEXT_ARM_SP mcontext (arm_sp) +MCONTEXT_ARM_LR mcontext (arm_lr) +MCONTEXT_ARM_PC mcontext (arm_pc) +MCONTEXT_ARM_CPSR mcontext (arm_cpsr) +MCONTEXT_FAULT_ADDRESS mcontext (fault_address) -- 1.7.10.4 _______________________________________________ uClibc mailing list [email protected] http://lists.busybox.net/mailman/listinfo/uclibc
