diff options
| -rw-r--r-- | linux-user/arm/signal.c | 105 |
1 files changed, 89 insertions, 16 deletions
diff --git a/linux-user/arm/signal.c b/linux-user/arm/signal.c index 0c1ec53025..eb72be5dd0 100644 --- a/linux-user/arm/signal.c +++ b/linux-user/arm/signal.c @@ -102,13 +102,13 @@ struct sigframe_v1 { struct target_sigcontext sc; abi_ulong extramask[TARGET_NSIG_WORDS-1]; - abi_ulong retcode; + abi_ulong retcode[4]; }; struct sigframe_v2 { struct target_ucontext_v2 uc; - abi_ulong retcode; + abi_ulong retcode[4]; }; struct rt_sigframe_v1 @@ -117,14 +117,14 @@ struct rt_sigframe_v1 abi_ulong puc; struct target_siginfo info; struct target_ucontext_v1 uc; - abi_ulong retcode; + abi_ulong retcode[4]; }; struct rt_sigframe_v2 { struct target_siginfo info; struct target_ucontext_v2 uc; - abi_ulong retcode; + abi_ulong retcode[4]; }; #define TARGET_CONFIG_CPU_32 1 @@ -147,6 +147,21 @@ static const abi_ulong retcodes[4] = { SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN }; +/* + * Stub needed to make sure the FD register (r9) contains the right + * value. + */ +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 */ +}; static inline int valid_user_regs(CPUARMState *regs) { @@ -200,13 +215,33 @@ get_sigframe(struct target_sigaction *ka, CPUARMState *regs, int framesize) return (sp - framesize) & ~7; } -static void +static int setup_return(CPUARMState *env, struct target_sigaction *ka, abi_ulong *rc, abi_ulong frame_addr, int usig, abi_ulong rc_addr) { - abi_ulong handler = ka->_sa_handler; + abi_ulong handler = 0; + abi_ulong handler_fdpic_GOT = 0; abi_ulong retcode; - int thumb = handler & 1; + + int thumb; + int is_fdpic = info_is_fdpic(((TaskState *)thread_cpu->opaque)->info); + + 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; + uint32_t cpsr = cpsr_read(env); cpsr &= ~CPSR_IT; @@ -217,7 +252,28 @@ setup_return(CPUARMState *env, struct target_sigaction *ka, } if (ka->sa_flags & TARGET_SA_RESTORER) { - retcode = ka->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; + } else { + retcode = ka->sa_restorer; + } } else { unsigned int idx = thumb; @@ -231,10 +287,15 @@ setup_return(CPUARMState *env, struct target_sigaction *ka, } env->regs[0] = usig; + if (is_fdpic) { + env->regs[9] = handler_fdpic_GOT; + } env->regs[13] = frame_addr; env->regs[14] = retcode; env->regs[15] = handler & (thumb ? ~1 : ~3); cpsr_write(env, cpsr, CPSR_IT | CPSR_T, CPSRWriteByInstr); + + return 0; } static abi_ulong *setup_sigframe_v2_vfp(abi_ulong *regspace, CPUARMState *env) @@ -327,12 +388,15 @@ static void setup_frame_v1(int usig, struct target_sigaction *ka, __put_user(set->sig[i], &frame->extramask[i - 1]); } - setup_return(regs, ka, &frame->retcode, frame_addr, usig, - frame_addr + offsetof(struct sigframe_v1, retcode)); + 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); } @@ -349,12 +413,15 @@ static void setup_frame_v2(int usig, struct target_sigaction *ka, setup_sigframe_v2(&frame->uc, set, regs); - setup_return(regs, ka, &frame->retcode, frame_addr, usig, - frame_addr + offsetof(struct sigframe_v2, retcode)); + 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); } @@ -404,8 +471,10 @@ static void setup_rt_frame_v1(int usig, struct target_sigaction *ka, __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]); } - setup_return(env, ka, &frame->retcode, frame_addr, usig, - frame_addr + offsetof(struct rt_sigframe_v1, retcode)); + if (setup_return(env, ka, frame->retcode, frame_addr, usig, + frame_addr + offsetof(struct rt_sigframe_v1, retcode))) { + goto sigsegv; + } env->regs[1] = info_addr; env->regs[2] = uc_addr; @@ -413,6 +482,7 @@ static void setup_rt_frame_v1(int usig, struct target_sigaction *ka, unlock_user_struct(frame, frame_addr, 1); return; sigsegv: + unlock_user_struct(frame, frame_addr, 1); force_sigsegv(usig); } @@ -435,8 +505,10 @@ static void setup_rt_frame_v2(int usig, struct target_sigaction *ka, setup_sigframe_v2(&frame->uc, set, env); - setup_return(env, ka, &frame->retcode, frame_addr, usig, - frame_addr + offsetof(struct rt_sigframe_v2, retcode)); + if (setup_return(env, ka, frame->retcode, frame_addr, usig, + frame_addr + offsetof(struct rt_sigframe_v2, retcode))) { + goto sigsegv; + } env->regs[1] = info_addr; env->regs[2] = uc_addr; @@ -444,6 +516,7 @@ static void setup_rt_frame_v2(int usig, struct target_sigaction *ka, unlock_user_struct(frame, frame_addr, 1); return; sigsegv: + unlock_user_struct(frame, frame_addr, 1); force_sigsegv(usig); } |