diff options
Diffstat (limited to 'linux-user/arm/signal.c')
| -rw-r--r-- | linux-user/arm/signal.c | 630 |
1 files changed, 630 insertions, 0 deletions
diff --git a/linux-user/arm/signal.c b/linux-user/arm/signal.c new file mode 100644 index 000000000..df9f8e8eb --- /dev/null +++ b/linux-user/arm/signal.c @@ -0,0 +1,630 @@ +/* + * Emulation of Linux signals + * + * Copyright (c) 2003 Fabrice Bellard + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ +#include "qemu/osdep.h" +#include "qemu.h" +#include "user-internals.h" +#include "signal-common.h" +#include "linux-user/trace.h" + +struct target_sigcontext { + abi_ulong trap_no; + abi_ulong error_code; + abi_ulong oldmask; + abi_ulong arm_r0; + abi_ulong arm_r1; + abi_ulong arm_r2; + abi_ulong arm_r3; + abi_ulong arm_r4; + abi_ulong arm_r5; + abi_ulong arm_r6; + abi_ulong arm_r7; + abi_ulong arm_r8; + abi_ulong arm_r9; + abi_ulong arm_r10; + abi_ulong arm_fp; + abi_ulong arm_ip; + abi_ulong arm_sp; + abi_ulong arm_lr; + abi_ulong arm_pc; + abi_ulong arm_cpsr; + abi_ulong fault_address; +}; + +struct target_ucontext { + abi_ulong tuc_flags; + abi_ulong tuc_link; + target_stack_t tuc_stack; + struct target_sigcontext tuc_mcontext; + target_sigset_t tuc_sigmask; /* mask last for extensibility */ + char __unused[128 - sizeof(target_sigset_t)]; + abi_ulong tuc_regspace[128] __attribute__((__aligned__(8))); +}; + +struct target_user_vfp { + uint64_t fpregs[32]; + abi_ulong fpscr; +}; + +struct target_user_vfp_exc { + abi_ulong fpexc; + abi_ulong fpinst; + abi_ulong fpinst2; +}; + +struct target_vfp_sigframe { + abi_ulong magic; + abi_ulong size; + struct target_user_vfp ufp; + struct target_user_vfp_exc ufp_exc; +} __attribute__((__aligned__(8))); + +struct target_iwmmxt_sigframe { + abi_ulong magic; + abi_ulong size; + uint64_t regs[16]; + /* Note that not all the coprocessor control registers are stored here */ + uint32_t wcssf; + uint32_t wcasf; + uint32_t wcgr0; + uint32_t wcgr1; + uint32_t wcgr2; + uint32_t wcgr3; +} __attribute__((__aligned__(8))); + +#define TARGET_VFP_MAGIC 0x56465001 +#define TARGET_IWMMXT_MAGIC 0x12ef842a + +struct sigframe +{ + struct target_ucontext uc; + abi_ulong retcode[4]; +}; + +struct rt_sigframe +{ + struct target_siginfo info; + struct sigframe sig; +}; + +static abi_ptr sigreturn_fdpic_tramp; + +/* + * Up to 3 words of 'retcode' in the sigframe are code, + * with retcode[3] being used by fdpic for the function descriptor. + * This code is not actually executed, but is retained for ABI compat. + * + * We will create a table of 8 retcode variants in the sigtramp page. + * Let each table entry use 3 words. + */ +#define RETCODE_WORDS 3 +#define RETCODE_BYTES (RETCODE_WORDS * 4) + +static inline int valid_user_regs(CPUARMState *regs) +{ + return 1; +} + +static void +setup_sigcontext(struct target_sigcontext *sc, /*struct _fpstate *fpstate,*/ + CPUARMState *env, abi_ulong mask) +{ + __put_user(env->regs[0], &sc->arm_r0); + __put_user(env->regs[1], &sc->arm_r1); + __put_user(env->regs[2], &sc->arm_r2); + __put_user(env->regs[3], &sc->arm_r3); + __put_user(env->regs[4], &sc->arm_r4); + __put_user(env->regs[5], &sc->arm_r5); + __put_user(env->regs[6], &sc->arm_r6); + __put_user(env->regs[7], &sc->arm_r7); + __put_user(env->regs[8], &sc->arm_r8); + __put_user(env->regs[9], &sc->arm_r9); + __put_user(env->regs[10], &sc->arm_r10); + __put_user(env->regs[11], &sc->arm_fp); + __put_user(env->regs[12], &sc->arm_ip); + __put_user(env->regs[13], &sc->arm_sp); + __put_user(env->regs[14], &sc->arm_lr); + __put_user(env->regs[15], &sc->arm_pc); + __put_user(cpsr_read(env), &sc->arm_cpsr); + + __put_user(/* current->thread.trap_no */ 0, &sc->trap_no); + __put_user(/* current->thread.error_code */ 0, &sc->error_code); + __put_user(/* current->thread.address */ 0, &sc->fault_address); + __put_user(mask, &sc->oldmask); +} + +static inline abi_ulong +get_sigframe(struct target_sigaction *ka, CPUARMState *regs, int framesize) +{ + unsigned long sp; + + sp = target_sigsp(get_sp_from_cpustate(regs), ka); + /* + * ATPCS B01 mandates 8-byte alignment + */ + return (sp - framesize) & ~7; +} + +static int +setup_return(CPUARMState *env, struct target_sigaction *ka, int usig, + struct sigframe *frame, abi_ulong sp_addr) +{ + abi_ulong handler = 0; + abi_ulong handler_fdpic_GOT = 0; + abi_ulong retcode; + int thumb, retcode_idx; + int is_fdpic = info_is_fdpic(((TaskState *)thread_cpu->opaque)->info); + bool copy_retcode; + + if (is_fdpic) { + /* In FDPIC mode, ka->_sa_handler points to a function + * descriptor (FD). The first word contains the address of the + * handler. The second word contains the value of the PIC + * register (r9). */ + abi_ulong funcdesc_ptr = ka->_sa_handler; + if (get_user_ual(handler, funcdesc_ptr) + || get_user_ual(handler_fdpic_GOT, funcdesc_ptr + 4)) { + return 1; + } + } else { + handler = ka->_sa_handler; + } + + thumb = handler & 1; + retcode_idx = thumb + (ka->sa_flags & TARGET_SA_SIGINFO ? 2 : 0); + + uint32_t cpsr = cpsr_read(env); + + cpsr &= ~CPSR_IT; + if (thumb) { + cpsr |= CPSR_T; + } else { + cpsr &= ~CPSR_T; + } + if (env->cp15.sctlr_el[1] & SCTLR_E0E) { + cpsr |= CPSR_E; + } else { + cpsr &= ~CPSR_E; + } + + if (ka->sa_flags & TARGET_SA_RESTORER) { + if (is_fdpic) { + __put_user((abi_ulong)ka->sa_restorer, &frame->retcode[3]); + retcode = (sigreturn_fdpic_tramp + + retcode_idx * RETCODE_BYTES + thumb); + copy_retcode = true; + } else { + retcode = ka->sa_restorer; + copy_retcode = false; + } + } else { + retcode = default_sigreturn + retcode_idx * RETCODE_BYTES + thumb; + copy_retcode = true; + } + + /* Copy the code to the stack slot for ABI compatibility. */ + if (copy_retcode) { + memcpy(frame->retcode, g2h_untagged(retcode & ~1), RETCODE_BYTES); + } + + env->regs[0] = usig; + if (is_fdpic) { + env->regs[9] = handler_fdpic_GOT; + } + env->regs[13] = sp_addr; + env->regs[14] = retcode; + env->regs[15] = handler & (thumb ? ~1 : ~3); + cpsr_write(env, cpsr, CPSR_IT | CPSR_T | CPSR_E, CPSRWriteByInstr); + + return 0; +} + +static abi_ulong *setup_sigframe_vfp(abi_ulong *regspace, CPUARMState *env) +{ + int i; + struct target_vfp_sigframe *vfpframe; + vfpframe = (struct target_vfp_sigframe *)regspace; + __put_user(TARGET_VFP_MAGIC, &vfpframe->magic); + __put_user(sizeof(*vfpframe), &vfpframe->size); + for (i = 0; i < 32; i++) { + __put_user(*aa32_vfp_dreg(env, i), &vfpframe->ufp.fpregs[i]); + } + __put_user(vfp_get_fpscr(env), &vfpframe->ufp.fpscr); + __put_user(env->vfp.xregs[ARM_VFP_FPEXC], &vfpframe->ufp_exc.fpexc); + __put_user(env->vfp.xregs[ARM_VFP_FPINST], &vfpframe->ufp_exc.fpinst); + __put_user(env->vfp.xregs[ARM_VFP_FPINST2], &vfpframe->ufp_exc.fpinst2); + return (abi_ulong*)(vfpframe+1); +} + +static abi_ulong *setup_sigframe_iwmmxt(abi_ulong *regspace, CPUARMState *env) +{ + int i; + struct target_iwmmxt_sigframe *iwmmxtframe; + iwmmxtframe = (struct target_iwmmxt_sigframe *)regspace; + __put_user(TARGET_IWMMXT_MAGIC, &iwmmxtframe->magic); + __put_user(sizeof(*iwmmxtframe), &iwmmxtframe->size); + for (i = 0; i < 16; i++) { + __put_user(env->iwmmxt.regs[i], &iwmmxtframe->regs[i]); + } + __put_user(env->vfp.xregs[ARM_IWMMXT_wCSSF], &iwmmxtframe->wcssf); + __put_user(env->vfp.xregs[ARM_IWMMXT_wCASF], &iwmmxtframe->wcssf); + __put_user(env->vfp.xregs[ARM_IWMMXT_wCGR0], &iwmmxtframe->wcgr0); + __put_user(env->vfp.xregs[ARM_IWMMXT_wCGR1], &iwmmxtframe->wcgr1); + __put_user(env->vfp.xregs[ARM_IWMMXT_wCGR2], &iwmmxtframe->wcgr2); + __put_user(env->vfp.xregs[ARM_IWMMXT_wCGR3], &iwmmxtframe->wcgr3); + return (abi_ulong*)(iwmmxtframe+1); +} + +static void setup_sigframe(struct target_ucontext *uc, + target_sigset_t *set, CPUARMState *env) +{ + struct target_sigaltstack stack; + int i; + abi_ulong *regspace; + + /* Clear all the bits of the ucontext we don't use. */ + memset(uc, 0, offsetof(struct target_ucontext, tuc_mcontext)); + + memset(&stack, 0, sizeof(stack)); + target_save_altstack(&stack, env); + memcpy(&uc->tuc_stack, &stack, sizeof(stack)); + + setup_sigcontext(&uc->tuc_mcontext, env, set->sig[0]); + /* Save coprocessor signal frame. */ + regspace = uc->tuc_regspace; + if (cpu_isar_feature(aa32_vfp_simd, env_archcpu(env))) { + regspace = setup_sigframe_vfp(regspace, env); + } + if (arm_feature(env, ARM_FEATURE_IWMMXT)) { + regspace = setup_sigframe_iwmmxt(regspace, env); + } + + /* Write terminating magic word */ + __put_user(0, regspace); + + for(i = 0; i < TARGET_NSIG_WORDS; i++) { + __put_user(set->sig[i], &uc->tuc_sigmask.sig[i]); + } +} + +void setup_frame(int usig, struct target_sigaction *ka, + target_sigset_t *set, CPUARMState *regs) +{ + struct sigframe *frame; + abi_ulong frame_addr = get_sigframe(ka, regs, sizeof(*frame)); + + trace_user_setup_frame(regs, frame_addr); + if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { + goto sigsegv; + } + + setup_sigframe(&frame->uc, set, regs); + + if (setup_return(regs, ka, usig, frame, frame_addr)) { + goto sigsegv; + } + + unlock_user_struct(frame, frame_addr, 1); + return; +sigsegv: + unlock_user_struct(frame, frame_addr, 1); + force_sigsegv(usig); +} + +void setup_rt_frame(int usig, struct target_sigaction *ka, + target_siginfo_t *info, + target_sigset_t *set, CPUARMState *env) +{ + struct rt_sigframe *frame; + abi_ulong frame_addr = get_sigframe(ka, env, sizeof(*frame)); + abi_ulong info_addr, uc_addr; + + trace_user_setup_rt_frame(env, frame_addr); + if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { + goto sigsegv; + } + + info_addr = frame_addr + offsetof(struct rt_sigframe, info); + uc_addr = frame_addr + offsetof(struct rt_sigframe, sig.uc); + tswap_siginfo(&frame->info, info); + + setup_sigframe(&frame->sig.uc, set, env); + + if (setup_return(env, ka, usig, &frame->sig, frame_addr)) { + goto sigsegv; + } + + env->regs[1] = info_addr; + env->regs[2] = uc_addr; + + unlock_user_struct(frame, frame_addr, 1); + return; +sigsegv: + unlock_user_struct(frame, frame_addr, 1); + force_sigsegv(usig); +} + +static int +restore_sigcontext(CPUARMState *env, struct target_sigcontext *sc) +{ + int err = 0; + uint32_t cpsr; + + __get_user(env->regs[0], &sc->arm_r0); + __get_user(env->regs[1], &sc->arm_r1); + __get_user(env->regs[2], &sc->arm_r2); + __get_user(env->regs[3], &sc->arm_r3); + __get_user(env->regs[4], &sc->arm_r4); + __get_user(env->regs[5], &sc->arm_r5); + __get_user(env->regs[6], &sc->arm_r6); + __get_user(env->regs[7], &sc->arm_r7); + __get_user(env->regs[8], &sc->arm_r8); + __get_user(env->regs[9], &sc->arm_r9); + __get_user(env->regs[10], &sc->arm_r10); + __get_user(env->regs[11], &sc->arm_fp); + __get_user(env->regs[12], &sc->arm_ip); + __get_user(env->regs[13], &sc->arm_sp); + __get_user(env->regs[14], &sc->arm_lr); + __get_user(env->regs[15], &sc->arm_pc); + __get_user(cpsr, &sc->arm_cpsr); + cpsr_write(env, cpsr, CPSR_USER | CPSR_EXEC, CPSRWriteByInstr); + + err |= !valid_user_regs(env); + + return err; +} + +static abi_ulong *restore_sigframe_vfp(CPUARMState *env, abi_ulong *regspace) +{ + int i; + abi_ulong magic, sz; + uint32_t fpscr, fpexc; + struct target_vfp_sigframe *vfpframe; + vfpframe = (struct target_vfp_sigframe *)regspace; + + __get_user(magic, &vfpframe->magic); + __get_user(sz, &vfpframe->size); + if (magic != TARGET_VFP_MAGIC || sz != sizeof(*vfpframe)) { + return 0; + } + for (i = 0; i < 32; i++) { + __get_user(*aa32_vfp_dreg(env, i), &vfpframe->ufp.fpregs[i]); + } + __get_user(fpscr, &vfpframe->ufp.fpscr); + vfp_set_fpscr(env, fpscr); + __get_user(fpexc, &vfpframe->ufp_exc.fpexc); + /* Sanitise FPEXC: ensure VFP is enabled, FPINST2 is invalid + * and the exception flag is cleared + */ + fpexc |= (1 << 30); + fpexc &= ~((1 << 31) | (1 << 28)); + env->vfp.xregs[ARM_VFP_FPEXC] = fpexc; + __get_user(env->vfp.xregs[ARM_VFP_FPINST], &vfpframe->ufp_exc.fpinst); + __get_user(env->vfp.xregs[ARM_VFP_FPINST2], &vfpframe->ufp_exc.fpinst2); + return (abi_ulong*)(vfpframe + 1); +} + +static abi_ulong *restore_sigframe_iwmmxt(CPUARMState *env, + abi_ulong *regspace) +{ + int i; + abi_ulong magic, sz; + struct target_iwmmxt_sigframe *iwmmxtframe; + iwmmxtframe = (struct target_iwmmxt_sigframe *)regspace; + + __get_user(magic, &iwmmxtframe->magic); + __get_user(sz, &iwmmxtframe->size); + if (magic != TARGET_IWMMXT_MAGIC || sz != sizeof(*iwmmxtframe)) { + return 0; + } + for (i = 0; i < 16; i++) { + __get_user(env->iwmmxt.regs[i], &iwmmxtframe->regs[i]); + } + __get_user(env->vfp.xregs[ARM_IWMMXT_wCSSF], &iwmmxtframe->wcssf); + __get_user(env->vfp.xregs[ARM_IWMMXT_wCASF], &iwmmxtframe->wcssf); + __get_user(env->vfp.xregs[ARM_IWMMXT_wCGR0], &iwmmxtframe->wcgr0); + __get_user(env->vfp.xregs[ARM_IWMMXT_wCGR1], &iwmmxtframe->wcgr1); + __get_user(env->vfp.xregs[ARM_IWMMXT_wCGR2], &iwmmxtframe->wcgr2); + __get_user(env->vfp.xregs[ARM_IWMMXT_wCGR3], &iwmmxtframe->wcgr3); + return (abi_ulong*)(iwmmxtframe + 1); +} + +static int do_sigframe_return(CPUARMState *env, + target_ulong context_addr, + struct target_ucontext *uc) +{ + sigset_t host_set; + abi_ulong *regspace; + + target_to_host_sigset(&host_set, &uc->tuc_sigmask); + set_sigmask(&host_set); + + if (restore_sigcontext(env, &uc->tuc_mcontext)) { + return 1; + } + + /* Restore coprocessor signal frame */ + regspace = uc->tuc_regspace; + if (cpu_isar_feature(aa32_vfp_simd, env_archcpu(env))) { + regspace = restore_sigframe_vfp(env, regspace); + if (!regspace) { + return 1; + } + } + if (arm_feature(env, ARM_FEATURE_IWMMXT)) { + regspace = restore_sigframe_iwmmxt(env, regspace); + if (!regspace) { + return 1; + } + } + + target_restore_altstack(&uc->tuc_stack, env); + +#if 0 + /* Send SIGTRAP if we're single-stepping */ + if (ptrace_cancel_bpt(current)) + send_sig(SIGTRAP, current, 1); +#endif + + return 0; +} + +long do_sigreturn(CPUARMState *env) +{ + abi_ulong frame_addr; + struct sigframe *frame = NULL; + + /* + * Since we stacked the signal on a 64-bit boundary, + * then 'sp' should be word aligned here. If it's + * not, then the user is trying to mess with us. + */ + frame_addr = env->regs[13]; + trace_user_do_sigreturn(env, frame_addr); + if (frame_addr & 7) { + goto badframe; + } + + if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { + goto badframe; + } + + if (do_sigframe_return(env, + frame_addr + offsetof(struct sigframe, uc), + &frame->uc)) { + goto badframe; + } + + unlock_user_struct(frame, frame_addr, 0); + return -TARGET_QEMU_ESIGRETURN; + +badframe: + unlock_user_struct(frame, frame_addr, 0); + force_sig(TARGET_SIGSEGV); + return -TARGET_QEMU_ESIGRETURN; +} + +long do_rt_sigreturn(CPUARMState *env) +{ + abi_ulong frame_addr; + struct rt_sigframe *frame = NULL; + + /* + * Since we stacked the signal on a 64-bit boundary, + * then 'sp' should be word aligned here. If it's + * not, then the user is trying to mess with us. + */ + frame_addr = env->regs[13]; + trace_user_do_rt_sigreturn(env, frame_addr); + if (frame_addr & 7) { + goto badframe; + } + + if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { + goto badframe; + } + + if (do_sigframe_return(env, + frame_addr + offsetof(struct rt_sigframe, sig.uc), + &frame->sig.uc)) { + goto badframe; + } + + unlock_user_struct(frame, frame_addr, 0); + return -TARGET_QEMU_ESIGRETURN; + +badframe: + unlock_user_struct(frame, frame_addr, 0); + force_sig(TARGET_SIGSEGV); + return -TARGET_QEMU_ESIGRETURN; +} + +/* + * EABI syscalls pass the number via r7. + * Note that the kernel still adds the OABI syscall number to the trap, + * presumably for backward ABI compatibility with unwinders. + */ +#define ARM_MOV_R7_IMM(X) (0xe3a07000 | (X)) +#define ARM_SWI_SYS(X) (0xef000000 | (X) | ARM_SYSCALL_BASE) + +#define THUMB_MOVS_R7_IMM(X) (0x2700 | (X)) +#define THUMB_SWI_SYS 0xdf00 + +static void write_arm_sigreturn(uint32_t *rc, int syscall) +{ + __put_user(ARM_MOV_R7_IMM(syscall), rc); + __put_user(ARM_SWI_SYS(syscall), rc + 1); + /* Wrote 8 of 12 bytes */ +} + +static void write_thm_sigreturn(uint32_t *rc, int syscall) +{ + __put_user(THUMB_SWI_SYS << 16 | THUMB_MOVS_R7_IMM(syscall), rc); + /* Wrote 4 of 12 bytes */ +} + +/* + * Stub needed to make sure the FD register (r9) contains the right value. + * Use the same instruction sequence as the kernel. + */ +static void write_arm_fdpic_sigreturn(uint32_t *rc, int ofs) +{ + assert(ofs <= 0xfff); + __put_user(0xe59d3000 | ofs, rc + 0); /* ldr r3, [sp, #ofs] */ + __put_user(0xe8930908, rc + 1); /* ldm r3, { r3, r9 } */ + __put_user(0xe12fff13, rc + 2); /* bx r3 */ + /* Wrote 12 of 12 bytes */ +} + +static void write_thm_fdpic_sigreturn(void *vrc, int ofs) +{ + uint16_t *rc = vrc; + + assert((ofs & ~0x3fc) == 0); + __put_user(0x9b00 | (ofs >> 2), rc + 0); /* ldr r3, [sp, #ofs] */ + __put_user(0xcb0c, rc + 1); /* ldm r3, { r2, r3 } */ + __put_user(0x4699, rc + 2); /* mov r9, r3 */ + __put_user(0x4710, rc + 3); /* bx r2 */ + /* Wrote 8 of 12 bytes */ +} + +void setup_sigtramp(abi_ulong sigtramp_page) +{ + uint32_t total_size = 8 * RETCODE_BYTES; + uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, total_size, 0); + + assert(tramp != NULL); + + default_sigreturn = sigtramp_page; + write_arm_sigreturn(&tramp[0 * RETCODE_WORDS], TARGET_NR_sigreturn); + write_thm_sigreturn(&tramp[1 * RETCODE_WORDS], TARGET_NR_sigreturn); + write_arm_sigreturn(&tramp[2 * RETCODE_WORDS], TARGET_NR_rt_sigreturn); + write_thm_sigreturn(&tramp[3 * RETCODE_WORDS], TARGET_NR_rt_sigreturn); + + sigreturn_fdpic_tramp = sigtramp_page + 4 * RETCODE_BYTES; + write_arm_fdpic_sigreturn(tramp + 4 * RETCODE_WORDS, + offsetof(struct sigframe, retcode[3])); + write_thm_fdpic_sigreturn(tramp + 5 * RETCODE_WORDS, + offsetof(struct sigframe, retcode[3])); + write_arm_fdpic_sigreturn(tramp + 6 * RETCODE_WORDS, + offsetof(struct rt_sigframe, sig.retcode[3])); + write_thm_fdpic_sigreturn(tramp + 7 * RETCODE_WORDS, + offsetof(struct rt_sigframe, sig.retcode[3])); + + unlock_user(tramp, sigtramp_page, total_size); +} |