Date: Sun, 20 Aug 2017 09:52:25 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r322720 - head/sys/amd64/amd64 Message-ID: <201708200952.v7K9qPP4036384@repo.freebsd.org>
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Author: kib Date: Sun Aug 20 09:52:25 2017 New Revision: 322720 URL: https://svnweb.freebsd.org/changeset/base/322720 Log: Simplify amd64 trap(). - Use more relevant name 'signo' instead of 'i' for the local variable which contains a signal number to send for the current exception. - Eliminate two labels 'userout' and 'out' which point to the very end of the trap() function. Instead use return directly. - Re-indent the prot_fault_translation block by reducing if() nesting. - Some more monor style changes. Requested and reviewed by: bde Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Modified: head/sys/amd64/amd64/trap.c Modified: head/sys/amd64/amd64/trap.c ============================================================================== --- head/sys/amd64/amd64/trap.c Sun Aug 20 09:42:09 2017 (r322719) +++ head/sys/amd64/amd64/trap.c Sun Aug 20 09:52:25 2017 (r322720) @@ -172,12 +172,12 @@ trap(struct trapframe *frame) #ifdef KDB register_t dr6; #endif - int i, ucode; + int signo, ucode; u_int type; td = curthread; p = td->td_proc; - i = 0; + signo = 0; ucode = 0; addr = 0; @@ -186,22 +186,20 @@ trap(struct trapframe *frame) #ifdef SMP /* Handler for NMI IPIs used for stopping CPUs. */ - if (type == T_NMI) { - if (ipi_nmi_handler() == 0) - goto out; - } -#endif /* SMP */ + if (type == T_NMI && ipi_nmi_handler() == 0) + return; +#endif #ifdef KDB if (kdb_active) { kdb_reenter(); - goto out; + return; } #endif if (type == T_RESERVED) { trap_fatal(frame, 0); - goto out; + return; } if (type == T_NMI) { @@ -214,18 +212,18 @@ trap(struct trapframe *frame) */ if (pmc_intr != NULL && (*pmc_intr)(PCPU_GET(cpuid), frame) != 0) - goto out; + return; #endif #ifdef STACK if (stack_nmi_handler(frame) != 0) - goto out; + return; #endif } if (type == T_MCHK) { mca_intr(); - goto out; + return; } if ((frame->tf_rflags & PSL_I) == 0) { @@ -269,7 +267,7 @@ trap(struct trapframe *frame) switch (type) { case T_PRIVINFLT: /* privileged instruction fault */ - i = SIGILL; + signo = SIGILL; ucode = ILL_PRVOPC; break; @@ -281,41 +279,41 @@ trap(struct trapframe *frame) fill_frame_regs(frame, ®s); if (dtrace_pid_probe_ptr != NULL && dtrace_pid_probe_ptr(®s) == 0) - goto out; + return; } #endif frame->tf_rflags &= ~PSL_T; - i = SIGTRAP; + signo = SIGTRAP; ucode = (type == T_TRCTRAP ? TRAP_TRACE : TRAP_BRKPT); break; case T_ARITHTRAP: /* arithmetic trap */ ucode = fputrap_x87(); if (ucode == -1) - goto userout; - i = SIGFPE; + return; + signo = SIGFPE; break; case T_PROTFLT: /* general protection fault */ - i = SIGBUS; + signo = SIGBUS; ucode = BUS_OBJERR; break; case T_STKFLT: /* stack fault */ case T_SEGNPFLT: /* segment not present fault */ - i = SIGBUS; + signo = SIGBUS; ucode = BUS_ADRERR; break; case T_TSSFLT: /* invalid TSS fault */ - i = SIGBUS; + signo = SIGBUS; ucode = BUS_OBJERR; break; case T_ALIGNFLT: - i = SIGBUS; + signo = SIGBUS; ucode = BUS_ADRALN; break; case T_DOUBLEFLT: /* double fault */ default: - i = SIGBUS; + signo = SIGBUS; ucode = BUS_OBJERR; break; @@ -325,67 +323,64 @@ trap(struct trapframe *frame) */ if (*p->p_sysent->sv_trap != NULL && (*p->p_sysent->sv_trap)(td) == 0) - goto userout; + return; addr = frame->tf_addr; - i = trap_pfault(frame, TRUE); - if (i == -1) - goto userout; - if (i == 0) - goto user; - - if (i == SIGSEGV) + signo = trap_pfault(frame, TRUE); + if (signo == -1) + return; + if (signo == 0) + goto userret; + if (signo == SIGSEGV) { ucode = SEGV_MAPERR; - else { - if (prot_fault_translation == 0) { - /* - * Autodetect. - * This check also covers the images - * without the ABI-tag ELF note. - */ - if (SV_CURPROC_ABI() == SV_ABI_FREEBSD - && p->p_osrel >= P_OSREL_SIGSEGV) { - i = SIGSEGV; - ucode = SEGV_ACCERR; - } else { - i = SIGBUS; - ucode = BUS_PAGE_FAULT; - } - } else if (prot_fault_translation == 1) { - /* - * Always compat mode. - */ - i = SIGBUS; - ucode = BUS_PAGE_FAULT; - } else { - /* - * Always SIGSEGV mode. - */ - i = SIGSEGV; + } else if (prot_fault_translation == 0) { + /* + * Autodetect. This check also covers + * the images without the ABI-tag ELF + * note. + */ + if (SV_CURPROC_ABI() == SV_ABI_FREEBSD && + p->p_osrel >= P_OSREL_SIGSEGV) { + signo = SIGSEGV; ucode = SEGV_ACCERR; + } else { + signo = SIGBUS; + ucode = BUS_PAGE_FAULT; } + } else if (prot_fault_translation == 1) { + /* + * Always compat mode. + */ + signo = SIGBUS; + ucode = BUS_PAGE_FAULT; + } else { + /* + * Always SIGSEGV mode. + */ + signo = SIGSEGV; + ucode = SEGV_ACCERR; } break; case T_DIVIDE: /* integer divide fault */ ucode = FPE_INTDIV; - i = SIGFPE; + signo = SIGFPE; break; #ifdef DEV_ISA case T_NMI: nmi_handle_intr(type, frame); - goto out; -#endif /* DEV_ISA */ + return; +#endif case T_OFLOW: /* integer overflow fault */ ucode = FPE_INTOVF; - i = SIGFPE; + signo = SIGFPE; break; case T_BOUND: /* bounds check fault */ ucode = FPE_FLTSUB; - i = SIGFPE; + signo = SIGFPE; break; case T_DNA: @@ -393,18 +388,18 @@ trap(struct trapframe *frame) KASSERT(PCB_USER_FPU(td->td_pcb), ("kernel FPU ctx has leaked")); fpudna(); - goto userout; + return; case T_FPOPFLT: /* FPU operand fetch fault */ ucode = ILL_COPROC; - i = SIGILL; + signo = SIGILL; break; case T_XMMFLT: /* SIMD floating-point exception */ ucode = fputrap_sse(); if (ucode == -1) - goto userout; - i = SIGFPE; + return; + signo = SIGFPE; break; #ifdef KDTRACE_HOOKS case T_DTRACE_RET: @@ -412,8 +407,8 @@ trap(struct trapframe *frame) fill_frame_regs(frame, ®s); if (dtrace_return_probe_ptr != NULL && dtrace_return_probe_ptr(®s) == 0) - goto out; - goto userout; + return; + return; #endif } } else { @@ -424,13 +419,13 @@ trap(struct trapframe *frame) switch (type) { case T_PAGEFLT: /* page fault */ (void) trap_pfault(frame, FALSE); - goto out; + return; case T_DNA: if (PCB_USER_FPU(td->td_pcb)) panic("Unregistered use of FPU in kernel"); fpudna(); - goto out; + return; case T_ARITHTRAP: /* arithmetic trap */ case T_XMMFLT: /* SIMD floating-point exception */ @@ -440,7 +435,7 @@ trap(struct trapframe *frame) * registration for FPU traps is overkill. */ trap_fatal(frame, 0); - goto out; + return; case T_STKFLT: /* stack fault */ case T_PROTFLT: /* general protection fault */ @@ -460,35 +455,35 @@ trap(struct trapframe *frame) */ if (frame->tf_rip == (long)doreti_iret) { frame->tf_rip = (long)doreti_iret_fault; - goto out; + return; } if (frame->tf_rip == (long)ld_ds) { frame->tf_rip = (long)ds_load_fault; - goto out; + return; } if (frame->tf_rip == (long)ld_es) { frame->tf_rip = (long)es_load_fault; - goto out; + return; } if (frame->tf_rip == (long)ld_fs) { frame->tf_rip = (long)fs_load_fault; - goto out; + return; } if (frame->tf_rip == (long)ld_gs) { frame->tf_rip = (long)gs_load_fault; - goto out; + return; } if (frame->tf_rip == (long)ld_gsbase) { frame->tf_rip = (long)gsbase_load_fault; - goto out; + return; } if (frame->tf_rip == (long)ld_fsbase) { frame->tf_rip = (long)fsbase_load_fault; - goto out; + return; } if (curpcb->pcb_onfault != NULL) { frame->tf_rip = (long)curpcb->pcb_onfault; - goto out; + return; } break; @@ -504,7 +499,7 @@ trap(struct trapframe *frame) */ if (frame->tf_rflags & PSL_NT) { frame->tf_rflags &= ~PSL_NT; - goto out; + return; } break; @@ -525,7 +520,7 @@ trap(struct trapframe *frame) * processor doesn't */ load_dr6(rdr6() & ~0xf); - goto out; + return; } /* * FALLTHROUGH (TRCTRAP kernel mode, kernel address) @@ -540,27 +535,27 @@ trap(struct trapframe *frame) dr6 = rdr6(); load_dr6(dr6 & ~0x4000); if (kdb_trap(type, dr6, frame)) - goto out; + return; #endif break; #ifdef DEV_ISA case T_NMI: nmi_handle_intr(type, frame); - goto out; -#endif /* DEV_ISA */ + return; +#endif } trap_fatal(frame, 0); - goto out; + return; } /* Translate fault for emulators (e.g. Linux) */ - if (*p->p_sysent->sv_transtrap) - i = (*p->p_sysent->sv_transtrap)(i, type); + if (*p->p_sysent->sv_transtrap != NULL) + signo = (*p->p_sysent->sv_transtrap)(signo, type); ksiginfo_init_trap(&ksi); - ksi.ksi_signo = i; + ksi.ksi_signo = signo; ksi.ksi_code = ucode; ksi.ksi_trapno = type; ksi.ksi_addr = (void *)addr; @@ -568,8 +563,8 @@ trap(struct trapframe *frame) uprintf("pid %d comm %s: signal %d err %lx code %d type %d " "addr 0x%lx rsp 0x%lx rip 0x%lx " "<%02x %02x %02x %02x %02x %02x %02x %02x>\n", - p->p_pid, p->p_comm, i, frame->tf_err, ucode, type, addr, - frame->tf_rsp, frame->tf_rip, + p->p_pid, p->p_comm, signo, frame->tf_err, ucode, type, + addr, frame->tf_rsp, frame->tf_rip, fubyte((void *)(frame->tf_rip + 0)), fubyte((void *)(frame->tf_rip + 1)), fubyte((void *)(frame->tf_rip + 2)), @@ -581,14 +576,10 @@ trap(struct trapframe *frame) } KASSERT((read_rflags() & PSL_I) != 0, ("interrupts disabled")); trapsignal(td, &ksi); - -user: +userret: userret(td, frame); KASSERT(PCB_USER_FPU(td->td_pcb), ("Return from trap with kernel FPU ctx leaked")); -userout: -out: - return; } /*
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