diff options
Diffstat (limited to 'linux-user/arm/signal.c')
| -rw-r--r-- | linux-user/arm/signal.c | 529 |
1 files changed, 170 insertions, 359 deletions
diff --git a/linux-user/arm/signal.c b/linux-user/arm/signal.c index b0e753801b..8db1c4b233 100644 --- a/linux-user/arm/signal.c +++ b/linux-user/arm/signal.c @@ -18,8 +18,11 @@ */ #include "qemu/osdep.h" #include "qemu.h" +#include "user-internals.h" #include "signal-common.h" #include "linux-user/trace.h" +#include "target/arm/cpu-features.h" +#include "vdso-asmoffset.h" struct target_sigcontext { abi_ulong trap_no; @@ -45,15 +48,7 @@ struct target_sigcontext { abi_ulong fault_address; }; -struct target_ucontext_v1 { - 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 */ -}; - -struct target_ucontext_v2 { +struct target_ucontext { abi_ulong tuc_flags; abi_ulong tuc_link; target_stack_t tuc_stack; @@ -97,70 +92,35 @@ struct target_iwmmxt_sigframe { #define TARGET_VFP_MAGIC 0x56465001 #define TARGET_IWMMXT_MAGIC 0x12ef842a -struct sigframe_v1 +struct sigframe { - struct target_sigcontext sc; - abi_ulong extramask[TARGET_NSIG_WORDS-1]; + struct target_ucontext uc; abi_ulong retcode[4]; }; -struct sigframe_v2 +struct rt_sigframe { - struct target_ucontext_v2 uc; - abi_ulong retcode[4]; -}; - -struct rt_sigframe_v1 -{ - abi_ulong pinfo; - abi_ulong puc; struct target_siginfo info; - struct target_ucontext_v1 uc; - abi_ulong retcode[4]; + struct sigframe sig; }; -struct rt_sigframe_v2 -{ - struct target_siginfo info; - struct target_ucontext_v2 uc; - abi_ulong retcode[4]; -}; +QEMU_BUILD_BUG_ON(offsetof(struct sigframe, retcode[3]) + != SIGFRAME_RC3_OFFSET); +QEMU_BUILD_BUG_ON(offsetof(struct rt_sigframe, sig.retcode[3]) + != RT_SIGFRAME_RC3_OFFSET); -#define TARGET_CONFIG_CPU_32 1 +static abi_ptr sigreturn_fdpic_tramp; /* - * For ARM syscalls, we encode the syscall number into the instruction. - */ -#define SWI_SYS_SIGRETURN (0xef000000|(TARGET_NR_sigreturn + ARM_SYSCALL_BASE)) -#define SWI_SYS_RT_SIGRETURN (0xef000000|(TARGET_NR_rt_sigreturn + ARM_SYSCALL_BASE)) - -/* - * For Thumb syscalls, we pass the syscall number via r7. We therefore - * need two 16-bit instructions. - */ -#define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (TARGET_NR_sigreturn)) -#define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (TARGET_NR_rt_sigreturn)) - -static const abi_ulong retcodes[4] = { - SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN, - SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN -}; - -/* - * Stub needed to make sure the FD register (r9) contains the right - * value. + * 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. */ -static const unsigned long sigreturn_fdpic_codes[3] = { - 0xe59fc004, /* ldr r12, [pc, #4] to read function descriptor */ - 0xe59c9004, /* ldr r9, [r12, #4] to setup GOT */ - 0xe59cf000 /* ldr pc, [r12] to jump into restorer */ -}; - -static const unsigned long sigreturn_fdpic_thumb_codes[3] = { - 0xc008f8df, /* ldr r12, [pc, #8] to read function descriptor */ - 0x9004f8dc, /* ldr r9, [r12, #4] to setup GOT */ - 0xf000f8dc /* ldr pc, [r12] to jump into restorer */ -}; +#define RETCODE_WORDS 3 +#define RETCODE_BYTES (RETCODE_WORDS * 4) static inline int valid_user_regs(CPUARMState *regs) { @@ -187,9 +147,7 @@ setup_sigcontext(struct target_sigcontext *sc, /*struct _fpstate *fpstate,*/ __put_user(env->regs[13], &sc->arm_sp); __put_user(env->regs[14], &sc->arm_lr); __put_user(env->regs[15], &sc->arm_pc); -#ifdef TARGET_CONFIG_CPU_32 __put_user(cpsr_read(env), &sc->arm_cpsr); -#endif __put_user(/* current->thread.trap_no */ 0, &sc->trap_no); __put_user(/* current->thread.error_code */ 0, &sc->error_code); @@ -209,16 +167,19 @@ get_sigframe(struct target_sigaction *ka, CPUARMState *regs, int framesize) return (sp - framesize) & ~7; } +static void write_arm_sigreturn(uint32_t *rc, int syscall); +static void write_arm_fdpic_sigreturn(uint32_t *rc, int ofs); + static int -setup_return(CPUARMState *env, struct target_sigaction *ka, - abi_ulong *rc, abi_ulong frame_addr, int usig, abi_ulong rc_addr) +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; - int is_fdpic = info_is_fdpic(((TaskState *)thread_cpu->opaque)->info); + bool is_fdpic = info_is_fdpic(get_task_state(thread_cpu)->info); + bool is_rt = ka->sa_flags & TARGET_SA_SIGINFO; + bool thumb; if (is_fdpic) { /* In FDPIC mode, ka->_sa_handler points to a function @@ -233,7 +194,6 @@ setup_return(CPUARMState *env, struct target_sigaction *ka, } else { handler = ka->_sa_handler; } - thumb = handler & 1; uint32_t cpsr = cpsr_read(env); @@ -244,55 +204,53 @@ setup_return(CPUARMState *env, struct target_sigaction *ka, } else { cpsr &= ~CPSR_T; } + if (env->cp15.sctlr_el[1] & SCTLR_E0E) { + cpsr |= CPSR_E; + } else { + cpsr &= ~CPSR_E; + } + + /* Our vdso default_sigreturn label is a table of entry points. */ + retcode = default_sigreturn + (is_fdpic * 2 + is_rt) * 8; + + /* + * Put the sigreturn code on the stack no matter which return + * mechanism we use in order to remain ABI compliant. + * Because this is about ABI, always use the A32 instructions, + * despite the fact that our actual vdso trampoline is T16. + */ + if (is_fdpic) { + write_arm_fdpic_sigreturn(frame->retcode, + is_rt ? RT_SIGFRAME_RC3_OFFSET + : SIGFRAME_RC3_OFFSET); + } else { + write_arm_sigreturn(frame->retcode, + is_rt ? TARGET_NR_rt_sigreturn + : TARGET_NR_sigreturn); + } if (ka->sa_flags & TARGET_SA_RESTORER) { if (is_fdpic) { - /* For FDPIC we ensure that the restorer is called with a - * correct r9 value. For that we need to write code on - * the stack that sets r9 and jumps back to restorer - * value. - */ - if (thumb) { - __put_user(sigreturn_fdpic_thumb_codes[0], rc); - __put_user(sigreturn_fdpic_thumb_codes[1], rc + 1); - __put_user(sigreturn_fdpic_thumb_codes[2], rc + 2); - __put_user((abi_ulong)ka->sa_restorer, rc + 3); - } else { - __put_user(sigreturn_fdpic_codes[0], rc); - __put_user(sigreturn_fdpic_codes[1], rc + 1); - __put_user(sigreturn_fdpic_codes[2], rc + 2); - __put_user((abi_ulong)ka->sa_restorer, rc + 3); - } - - retcode = rc_addr + thumb; + /* Place the function descriptor in slot 3. */ + __put_user((abi_ulong)ka->sa_restorer, &frame->retcode[3]); } else { retcode = ka->sa_restorer; } - } else { - unsigned int idx = thumb; - - if (ka->sa_flags & TARGET_SA_SIGINFO) { - idx += 2; - } - - __put_user(retcodes[idx], rc); - - retcode = rc_addr + thumb; } env->regs[0] = usig; if (is_fdpic) { env->regs[9] = handler_fdpic_GOT; } - env->regs[13] = frame_addr; + env->regs[13] = sp_addr; env->regs[14] = retcode; env->regs[15] = handler & (thumb ? ~1 : ~3); - cpsr_write(env, cpsr, CPSR_IT | CPSR_T, CPSRWriteByInstr); + cpsr_write(env, cpsr, CPSR_IT | CPSR_T | CPSR_E, CPSRWriteByInstr); return 0; } -static abi_ulong *setup_sigframe_v2_vfp(abi_ulong *regspace, CPUARMState *env) +static abi_ulong *setup_sigframe_vfp(abi_ulong *regspace, CPUARMState *env) { int i; struct target_vfp_sigframe *vfpframe; @@ -309,8 +267,7 @@ static abi_ulong *setup_sigframe_v2_vfp(abi_ulong *regspace, CPUARMState *env) return (abi_ulong*)(vfpframe+1); } -static abi_ulong *setup_sigframe_v2_iwmmxt(abi_ulong *regspace, - CPUARMState *env) +static abi_ulong *setup_sigframe_iwmmxt(abi_ulong *regspace, CPUARMState *env) { int i; struct target_iwmmxt_sigframe *iwmmxtframe; @@ -329,15 +286,15 @@ static abi_ulong *setup_sigframe_v2_iwmmxt(abi_ulong *regspace, return (abi_ulong*)(iwmmxtframe+1); } -static void setup_sigframe_v2(struct target_ucontext_v2 *uc, - target_sigset_t *set, CPUARMState *env) +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_v2, tuc_mcontext)); + memset(uc, 0, offsetof(struct target_ucontext, tuc_mcontext)); memset(&stack, 0, sizeof(stack)); target_save_altstack(&stack, env); @@ -346,11 +303,11 @@ static void setup_sigframe_v2(struct target_ucontext_v2 *uc, setup_sigcontext(&uc->tuc_mcontext, env, set->sig[0]); /* Save coprocessor signal frame. */ regspace = uc->tuc_regspace; - if (arm_feature(env, ARM_FEATURE_VFP)) { - regspace = setup_sigframe_v2_vfp(regspace, env); + 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_v2_iwmmxt(regspace, env); + regspace = setup_sigframe_iwmmxt(regspace, env); } /* Write terminating magic word */ @@ -361,114 +318,23 @@ static void setup_sigframe_v2(struct target_ucontext_v2 *uc, } } -/* compare linux/arch/arm/kernel/signal.c:setup_frame() */ -static void setup_frame_v1(int usig, struct target_sigaction *ka, - target_sigset_t *set, CPUARMState *regs) -{ - struct sigframe_v1 *frame; - abi_ulong frame_addr = get_sigframe(ka, regs, sizeof(*frame)); - int i; - - trace_user_setup_frame(regs, frame_addr); - if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { - goto sigsegv; - } - - setup_sigcontext(&frame->sc, regs, set->sig[0]); - - for(i = 1; i < TARGET_NSIG_WORDS; i++) { - __put_user(set->sig[i], &frame->extramask[i - 1]); - } - - if (setup_return(regs, ka, frame->retcode, frame_addr, usig, - frame_addr + offsetof(struct sigframe_v1, retcode))) { - goto sigsegv; - } - - unlock_user_struct(frame, frame_addr, 1); - return; -sigsegv: - unlock_user_struct(frame, frame_addr, 1); - force_sigsegv(usig); -} - -static void setup_frame_v2(int usig, struct target_sigaction *ka, - target_sigset_t *set, CPUARMState *regs) -{ - struct sigframe_v2 *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_v2(&frame->uc, set, regs); - - if (setup_return(regs, ka, frame->retcode, frame_addr, usig, - frame_addr + offsetof(struct sigframe_v2, retcode))) { - goto sigsegv; - } - - unlock_user_struct(frame, frame_addr, 1); - return; -sigsegv: - unlock_user_struct(frame, frame_addr, 1); - force_sigsegv(usig); -} - void setup_frame(int usig, struct target_sigaction *ka, target_sigset_t *set, CPUARMState *regs) { - if (get_osversion() >= 0x020612) { - setup_frame_v2(usig, ka, set, regs); - } else { - setup_frame_v1(usig, ka, set, regs); - } -} - -/* compare linux/arch/arm/kernel/signal.c:setup_rt_frame() */ -static void setup_rt_frame_v1(int usig, struct target_sigaction *ka, - target_siginfo_t *info, - target_sigset_t *set, CPUARMState *env) -{ - struct rt_sigframe_v1 *frame; - abi_ulong frame_addr = get_sigframe(ka, env, sizeof(*frame)); - struct target_sigaltstack stack; - int i; - abi_ulong info_addr, uc_addr; + struct sigframe *frame; + abi_ulong frame_addr = get_sigframe(ka, regs, sizeof(*frame)); - trace_user_setup_rt_frame(env, frame_addr); + trace_user_setup_frame(regs, frame_addr); if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) { goto sigsegv; } - info_addr = frame_addr + offsetof(struct rt_sigframe_v1, info); - __put_user(info_addr, &frame->pinfo); - uc_addr = frame_addr + offsetof(struct rt_sigframe_v1, uc); - __put_user(uc_addr, &frame->puc); - tswap_siginfo(&frame->info, info); + setup_sigframe(&frame->uc, set, regs); - /* Clear all the bits of the ucontext we don't use. */ - memset(&frame->uc, 0, offsetof(struct target_ucontext_v1, tuc_mcontext)); - - memset(&stack, 0, sizeof(stack)); - target_save_altstack(&stack, env); - memcpy(&frame->uc.tuc_stack, &stack, sizeof(stack)); - - setup_sigcontext(&frame->uc.tuc_mcontext, env, set->sig[0]); - for(i = 0; i < TARGET_NSIG_WORDS; i++) { - __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]); - } - - if (setup_return(env, ka, frame->retcode, frame_addr, usig, - frame_addr + offsetof(struct rt_sigframe_v1, retcode))) { + if (setup_return(regs, ka, usig, frame, frame_addr)) { goto sigsegv; } - env->regs[1] = info_addr; - env->regs[2] = uc_addr; - unlock_user_struct(frame, frame_addr, 1); return; sigsegv: @@ -476,11 +342,11 @@ sigsegv: force_sigsegv(usig); } -static void setup_rt_frame_v2(int usig, struct target_sigaction *ka, - target_siginfo_t *info, - target_sigset_t *set, CPUARMState *env) +void setup_rt_frame(int usig, struct target_sigaction *ka, + target_siginfo_t *info, + target_sigset_t *set, CPUARMState *env) { - struct rt_sigframe_v2 *frame; + struct rt_sigframe *frame; abi_ulong frame_addr = get_sigframe(ka, env, sizeof(*frame)); abi_ulong info_addr, uc_addr; @@ -489,14 +355,13 @@ static void setup_rt_frame_v2(int usig, struct target_sigaction *ka, goto sigsegv; } - info_addr = frame_addr + offsetof(struct rt_sigframe_v2, info); - uc_addr = frame_addr + offsetof(struct rt_sigframe_v2, uc); - tswap_siginfo(&frame->info, info); + info_addr = frame_addr + offsetof(struct rt_sigframe, info); + uc_addr = frame_addr + offsetof(struct rt_sigframe, sig.uc); + frame->info = *info; - setup_sigframe_v2(&frame->uc, set, env); + setup_sigframe(&frame->sig.uc, set, env); - if (setup_return(env, ka, frame->retcode, frame_addr, usig, - frame_addr + offsetof(struct rt_sigframe_v2, retcode))) { + if (setup_return(env, ka, usig, &frame->sig, frame_addr)) { goto sigsegv; } @@ -510,17 +375,6 @@ sigsegv: force_sigsegv(usig); } -void setup_rt_frame(int usig, struct target_sigaction *ka, - target_siginfo_t *info, - target_sigset_t *set, CPUARMState *env) -{ - if (get_osversion() >= 0x020612) { - setup_rt_frame_v2(usig, ka, info, set, env); - } else { - setup_rt_frame_v1(usig, ka, info, set, env); - } -} - static int restore_sigcontext(CPUARMState *env, struct target_sigcontext *sc) { @@ -543,65 +397,15 @@ restore_sigcontext(CPUARMState *env, struct target_sigcontext *sc) __get_user(env->regs[13], &sc->arm_sp); __get_user(env->regs[14], &sc->arm_lr); __get_user(env->regs[15], &sc->arm_pc); -#ifdef TARGET_CONFIG_CPU_32 __get_user(cpsr, &sc->arm_cpsr); cpsr_write(env, cpsr, CPSR_USER | CPSR_EXEC, CPSRWriteByInstr); -#endif err |= !valid_user_regs(env); return err; } -static long do_sigreturn_v1(CPUARMState *env) -{ - abi_ulong frame_addr; - struct sigframe_v1 *frame = NULL; - target_sigset_t set; - sigset_t host_set; - int i; - - /* - * 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; - } - - __get_user(set.sig[0], &frame->sc.oldmask); - for(i = 1; i < TARGET_NSIG_WORDS; i++) { - __get_user(set.sig[i], &frame->extramask[i - 1]); - } - - target_to_host_sigset_internal(&host_set, &set); - set_sigmask(&host_set); - - if (restore_sigcontext(env, &frame->sc)) { - goto badframe; - } - -#if 0 - /* Send SIGTRAP if we're single-stepping */ - if (ptrace_cancel_bpt(current)) - send_sig(SIGTRAP, current, 1); -#endif - unlock_user_struct(frame, frame_addr, 0); - return -TARGET_QEMU_ESIGRETURN; - -badframe: - force_sig(TARGET_SIGSEGV); - return -TARGET_QEMU_ESIGRETURN; -} - -static abi_ulong *restore_sigframe_v2_vfp(CPUARMState *env, abi_ulong *regspace) +static abi_ulong *restore_sigframe_vfp(CPUARMState *env, abi_ulong *regspace) { int i; abi_ulong magic, sz; @@ -631,8 +435,8 @@ static abi_ulong *restore_sigframe_v2_vfp(CPUARMState *env, abi_ulong *regspace) return (abi_ulong*)(vfpframe + 1); } -static abi_ulong *restore_sigframe_v2_iwmmxt(CPUARMState *env, - abi_ulong *regspace) +static abi_ulong *restore_sigframe_iwmmxt(CPUARMState *env, + abi_ulong *regspace) { int i; abi_ulong magic, sz; @@ -656,9 +460,9 @@ static abi_ulong *restore_sigframe_v2_iwmmxt(CPUARMState *env, return (abi_ulong*)(iwmmxtframe + 1); } -static int do_sigframe_return_v2(CPUARMState *env, - target_ulong context_addr, - struct target_ucontext_v2 *uc) +static int do_sigframe_return(CPUARMState *env, + target_ulong context_addr, + struct target_ucontext *uc) { sigset_t host_set; abi_ulong *regspace; @@ -666,29 +470,26 @@ static int do_sigframe_return_v2(CPUARMState *env, target_to_host_sigset(&host_set, &uc->tuc_sigmask); set_sigmask(&host_set); - if (restore_sigcontext(env, &uc->tuc_mcontext)) + if (restore_sigcontext(env, &uc->tuc_mcontext)) { return 1; + } /* Restore coprocessor signal frame */ regspace = uc->tuc_regspace; - if (arm_feature(env, ARM_FEATURE_VFP)) { - regspace = restore_sigframe_v2_vfp(env, 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_v2_iwmmxt(env, regspace); + regspace = restore_sigframe_iwmmxt(env, regspace); if (!regspace) { return 1; } } - if (do_sigaltstack(context_addr - + offsetof(struct target_ucontext_v2, tuc_stack), - 0, get_sp_from_cpustate(env)) == -EFAULT) { - return 1; - } + target_restore_altstack(&uc->tuc_stack, env); #if 0 /* Send SIGTRAP if we're single-stepping */ @@ -699,10 +500,10 @@ static int do_sigframe_return_v2(CPUARMState *env, return 0; } -static long do_sigreturn_v2(CPUARMState *env) +long do_sigreturn(CPUARMState *env) { abi_ulong frame_addr; - struct sigframe_v2 *frame = NULL; + struct sigframe *frame = NULL; /* * Since we stacked the signal on a 64-bit boundary, @@ -719,36 +520,25 @@ static long do_sigreturn_v2(CPUARMState *env) goto badframe; } - if (do_sigframe_return_v2(env, - frame_addr - + offsetof(struct sigframe_v2, uc), - &frame->uc)) { + 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; + return -QEMU_ESIGRETURN; badframe: unlock_user_struct(frame, frame_addr, 0); force_sig(TARGET_SIGSEGV); - return -TARGET_QEMU_ESIGRETURN; -} - -long do_sigreturn(CPUARMState *env) -{ - if (get_osversion() >= 0x020612) { - return do_sigreturn_v2(env); - } else { - return do_sigreturn_v1(env); - } + return -QEMU_ESIGRETURN; } -static long do_rt_sigreturn_v1(CPUARMState *env) +long do_rt_sigreturn(CPUARMState *env) { abi_ulong frame_addr; - struct rt_sigframe_v1 *frame = NULL; - sigset_t host_set; + struct rt_sigframe *frame = NULL; /* * Since we stacked the signal on a 64-bit boundary, @@ -765,71 +555,92 @@ static long do_rt_sigreturn_v1(CPUARMState *env) goto badframe; } - target_to_host_sigset(&host_set, &frame->uc.tuc_sigmask); - set_sigmask(&host_set); - - if (restore_sigcontext(env, &frame->uc.tuc_mcontext)) { + if (do_sigframe_return(env, + frame_addr + offsetof(struct rt_sigframe, sig.uc), + &frame->sig.uc)) { goto badframe; } - if (do_sigaltstack(frame_addr + offsetof(struct rt_sigframe_v1, uc.tuc_stack), 0, get_sp_from_cpustate(env)) == -EFAULT) - goto badframe; - -#if 0 - /* Send SIGTRAP if we're single-stepping */ - if (ptrace_cancel_bpt(current)) - send_sig(SIGTRAP, current, 1); -#endif unlock_user_struct(frame, frame_addr, 0); - return -TARGET_QEMU_ESIGRETURN; + return -QEMU_ESIGRETURN; badframe: unlock_user_struct(frame, frame_addr, 0); force_sig(TARGET_SIGSEGV); - return -TARGET_QEMU_ESIGRETURN; + return -QEMU_ESIGRETURN; } -static long do_rt_sigreturn_v2(CPUARMState *env) -{ - abi_ulong frame_addr; - struct rt_sigframe_v2 *frame = NULL; +/* + * 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) - /* - * 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; - } +#define THUMB_MOVS_R7_IMM(X) (0x2700 | (X)) +#define THUMB_SWI_SYS 0xdf00 - if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) { - goto badframe; - } +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 */ +} - if (do_sigframe_return_v2(env, - frame_addr - + offsetof(struct rt_sigframe_v2, uc), - &frame->uc)) { - goto badframe; - } +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 */ +} - unlock_user_struct(frame, frame_addr, 0); - return -TARGET_QEMU_ESIGRETURN; +/* + * 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 */ +} -badframe: - unlock_user_struct(frame, frame_addr, 0); - force_sig(TARGET_SIGSEGV); - return -TARGET_QEMU_ESIGRETURN; +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 */ } -long do_rt_sigreturn(CPUARMState *env) +void setup_sigtramp(abi_ulong sigtramp_page) { - if (get_osversion() >= 0x020612) { - return do_rt_sigreturn_v2(env); - } else { - return do_rt_sigreturn_v1(env); - } + 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); } |