From: Bodo Stroesser Date: Thu, 5 May 2005 23:15:31 +0000 (-0700) Subject: [PATCH] uml: S390 preparation, abstract host page fault data X-Git-Tag: v2.6.12-rc4~88 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c578455a3eccf4dd7bd111e77129c301d6d67914;p=linux-2.6 [PATCH] uml: S390 preparation, abstract host page fault data This patch removes the arch-specific fault/trap-infos from thread and skas-regs. It adds a new struct faultinfo, that is arch-specific defined in sysdep/faultinfo.h. The structure is inserted in thread.arch and thread.regs.skas and thread.regs.tt Now, segv and other trap-handlers can copy the contents from regs.X.faultinfo to thread.arch.faultinfo with one simple assignment. Also, the number of macros necessary is reduced to FAULT_ADDRESS(struct faultinfo) extracts the faulting address from faultinfo FAULT_WRITE(struct faultinfo) extracts the "is_write" flag SEGV_IS_FIXABLE(struct faultinfo) is true for the fixable segvs, i.e. (TRAP == 14) on i386 UPT_FAULTINFO(regs) result is (struct faultinfo *) to the faultinfo in regs->skas.faultinfo GET_FAULTINFO_FROM_SC(struct faultinfo, struct sigcontext *) copies the relevant parts of the sigcontext to struct faultinfo. On SIGSEGV, call user_signal() instead of handle_segv(), if the architecture provides the information needed in PTRACE_FAULTINFO, or if PTRACE_FAULTINFO is missing, because segv-stub will provide the info. The benefit of the change is, that in case of a non-fixable SIGSEGV, we can give user processes a SIGSEGV, instead of possibly looping on pagefault handling. Since handle_segv() sikked arch_fixup() implicitly by passing ip==0 to segv(), I changed segv() to call arch_fixup() only, if !is_user. Signed-off-by: Bodo Stroesser Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/um/include/kern_util.h b/arch/um/include/kern_util.h index 15389c886b..e5fec55701 100644 --- a/arch/um/include/kern_util.h +++ b/arch/um/include/kern_util.h @@ -8,6 +8,7 @@ #include "linux/threads.h" #include "sysdep/ptrace.h" +#include "sysdep/faultinfo.h" extern int ncpus; extern char *linux_prog; @@ -31,8 +32,8 @@ extern int current_pid(void); extern unsigned long alloc_stack(int order, int atomic); extern int do_signal(void); extern int is_stack_fault(unsigned long sp); -extern unsigned long segv(unsigned long address, unsigned long ip, - int is_write, int is_user, void *sc); +extern unsigned long segv(struct faultinfo fi, unsigned long ip, + int is_user, void *sc); extern int handle_page_fault(unsigned long address, unsigned long ip, int is_write, int is_user, int *code_out); extern void syscall_ready(void); @@ -82,7 +83,7 @@ extern void timer_irq(union uml_pt_regs *regs); extern void unprotect_stack(unsigned long stack); extern void do_uml_exitcalls(void); extern int attach_debugger(int idle_pid, int pid, int stop); -extern void bad_segv(unsigned long address, unsigned long ip, int is_write); +extern void bad_segv(struct faultinfo fi, unsigned long ip); extern int config_gdb(char *str); extern int remove_gdb(void); extern char *uml_strdup(char *string); diff --git a/arch/um/include/sysdep-i386/faultinfo.h b/arch/um/include/sysdep-i386/faultinfo.h new file mode 100644 index 0000000000..db437cc373 --- /dev/null +++ b/arch/um/include/sysdep-i386/faultinfo.h @@ -0,0 +1,29 @@ +/* + * Copyright (C) 2004 Fujitsu Siemens Computers GmbH + * Author: Bodo Stroesser + * Licensed under the GPL + */ + +#ifndef __FAULTINFO_I386_H +#define __FAULTINFO_I386_H + +/* this structure contains the full arch-specific faultinfo + * from the traps. + * On i386, ptrace_faultinfo unfortunately doesn't provide + * all the info, since trap_no is missing. + * All common elements are defined at the same position in + * both structures, thus making it easy to copy the + * contents without knowledge about the structure elements. + */ +struct faultinfo { + int error_code; /* in ptrace_faultinfo misleadingly called is_write */ + unsigned long cr2; /* in ptrace_faultinfo called addr */ + int trap_no; /* missing in ptrace_faultinfo */ +}; + +#define FAULT_WRITE(fi) ((fi).error_code & 2) +#define FAULT_ADDRESS(fi) ((fi).cr2) + +#define PTRACE_FULL_FAULTINFO 0 + +#endif diff --git a/arch/um/include/sysdep-i386/ptrace.h b/arch/um/include/sysdep-i386/ptrace.h index 661d495e20..84ec7ff5cf 100644 --- a/arch/um/include/sysdep-i386/ptrace.h +++ b/arch/um/include/sysdep-i386/ptrace.h @@ -31,6 +31,7 @@ extern int sysemu_supported; #ifdef UML_CONFIG_MODE_SKAS #include "skas_ptregs.h" +#include "sysdep/faultinfo.h" #define REGS_IP(r) ((r)[HOST_IP]) #define REGS_SP(r) ((r)[HOST_SP]) @@ -53,12 +54,6 @@ extern int sysemu_supported; #define REGS_RESTART_SYSCALL(r) IP_RESTART_SYSCALL(REGS_IP(r)) -#define REGS_SEGV_IS_FIXABLE(r) SEGV_IS_FIXABLE((r)->trap_type) - -#define REGS_FAULT_ADDR(r) ((r)->fault_addr) - -#define REGS_FAULT_WRITE(r) FAULT_WRITE((r)->fault_type) - #endif #ifndef PTRACE_SYSEMU_SINGLESTEP #define PTRACE_SYSEMU_SINGLESTEP 32 @@ -71,6 +66,7 @@ union uml_pt_regs { struct tt_regs { long syscall; void *sc; + struct faultinfo faultinfo; } tt; #endif #ifdef UML_CONFIG_MODE_SKAS @@ -78,9 +74,7 @@ union uml_pt_regs { unsigned long regs[HOST_FRAME_SIZE]; unsigned long fp[HOST_FP_SIZE]; unsigned long xfp[HOST_XFP_SIZE]; - unsigned long fault_addr; - unsigned long fault_type; - unsigned long trap_type; + struct faultinfo faultinfo; long syscall; int is_user; } skas; @@ -217,15 +211,8 @@ struct syscall_args { #define UPT_SYSCALL_NR(r) UPT_ORIG_EAX(r) #define UPT_SYSCALL_RET(r) UPT_EAX(r) -#define UPT_SEGV_IS_FIXABLE(r) \ - CHOOSE_MODE(SC_SEGV_IS_FIXABLE(UPT_SC(r)), \ - REGS_SEGV_IS_FIXABLE(&r->skas)) - -#define UPT_FAULT_ADDR(r) \ - __CHOOSE_MODE(SC_FAULT_ADDR(UPT_SC(r)), REGS_FAULT_ADDR(&r->skas)) - -#define UPT_FAULT_WRITE(r) \ - CHOOSE_MODE(SC_FAULT_WRITE(UPT_SC(r)), REGS_FAULT_WRITE(&r->skas)) +#define UPT_FAULTINFO(r) \ + CHOOSE_MODE((&(r)->tt.faultinfo), (&(r)->skas.faultinfo)) #endif diff --git a/arch/um/include/sysdep-i386/sigcontext.h b/arch/um/include/sysdep-i386/sigcontext.h index dfee589de3..1fe7292651 100644 --- a/arch/um/include/sysdep-i386/sigcontext.h +++ b/arch/um/include/sysdep-i386/sigcontext.h @@ -13,15 +13,12 @@ #define SC_RESTART_SYSCALL(sc) IP_RESTART_SYSCALL(SC_IP(sc)) #define SC_SET_SYSCALL_RETURN(sc, result) SC_EAX(sc) = (result) -#define SC_FAULT_ADDR(sc) SC_CR2(sc) -#define SC_FAULT_TYPE(sc) SC_ERR(sc) - -#define FAULT_WRITE(err) (err & 2) -#define TO_SC_ERR(is_write) ((is_write) ? 2 : 0) - -#define SC_FAULT_WRITE(sc) (FAULT_WRITE(SC_ERR(sc))) - -#define SC_TRAP_TYPE(sc) SC_TRAPNO(sc) +#define GET_FAULTINFO_FROM_SC(fi,sc) \ + { \ + (fi).cr2 = SC_CR2(sc); \ + (fi).error_code = SC_ERR(sc); \ + (fi).trap_no = SC_TRAPNO(sc); \ + } /* ptrace expects that, at the start of a system call, %eax contains * -ENOSYS, so this makes it so. @@ -29,9 +26,7 @@ #define SC_START_SYSCALL(sc) do SC_EAX(sc) = -ENOSYS; while(0) /* This is Page Fault */ -#define SEGV_IS_FIXABLE(trap) (trap == 14) - -#define SC_SEGV_IS_FIXABLE(sc) (SEGV_IS_FIXABLE(SC_TRAPNO(sc))) +#define SEGV_IS_FIXABLE(fi) ((fi)->trap_no == 14) extern unsigned long *sc_sigmask(void *sc_ptr); extern int sc_get_fpregs(unsigned long buf, void *sc_ptr); diff --git a/arch/um/include/sysdep-i386/skas_ptrace.h b/arch/um/include/sysdep-i386/skas_ptrace.h new file mode 100644 index 0000000000..e27b8a7917 --- /dev/null +++ b/arch/um/include/sysdep-i386/skas_ptrace.h @@ -0,0 +1,22 @@ +/* + * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com) + * Licensed under the GPL + */ + +#ifndef __SYSDEP_I386_SKAS_PTRACE_H +#define __SYSDEP_I386_SKAS_PTRACE_H + +struct ptrace_faultinfo { + int is_write; + unsigned long addr; +}; + +struct ptrace_ldt { + int func; + void *ptr; + unsigned long bytecount; +}; + +#define PTRACE_LDT 54 + +#endif diff --git a/arch/um/include/sysdep-ia64/skas_ptrace.h b/arch/um/include/sysdep-ia64/skas_ptrace.h new file mode 100644 index 0000000000..25a38e7157 --- /dev/null +++ b/arch/um/include/sysdep-ia64/skas_ptrace.h @@ -0,0 +1,22 @@ +/* + * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com) + * Licensed under the GPL + */ + +#ifndef __SYSDEP_IA64_SKAS_PTRACE_H +#define __SYSDEP_IA64_SKAS_PTRACE_H + +struct ptrace_faultinfo { + int is_write; + unsigned long addr; +}; + +struct ptrace_ldt { + int func; + void *ptr; + unsigned long bytecount; +}; + +#define PTRACE_LDT 54 + +#endif diff --git a/arch/um/include/sysdep-ppc/skas_ptrace.h b/arch/um/include/sysdep-ppc/skas_ptrace.h new file mode 100644 index 0000000000..d9fbbac10d --- /dev/null +++ b/arch/um/include/sysdep-ppc/skas_ptrace.h @@ -0,0 +1,22 @@ +/* + * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com) + * Licensed under the GPL + */ + +#ifndef __SYSDEP_PPC_SKAS_PTRACE_H +#define __SYSDEP_PPC_SKAS_PTRACE_H + +struct ptrace_faultinfo { + int is_write; + unsigned long addr; +}; + +struct ptrace_ldt { + int func; + void *ptr; + unsigned long bytecount; +}; + +#define PTRACE_LDT 54 + +#endif diff --git a/arch/um/include/sysdep-x86_64/faultinfo.h b/arch/um/include/sysdep-x86_64/faultinfo.h new file mode 100644 index 0000000000..cb917b0d56 --- /dev/null +++ b/arch/um/include/sysdep-x86_64/faultinfo.h @@ -0,0 +1,29 @@ +/* + * Copyright (C) 2004 Fujitsu Siemens Computers GmbH + * Author: Bodo Stroesser + * Licensed under the GPL + */ + +#ifndef __FAULTINFO_X86_64_H +#define __FAULTINFO_X86_64_H + +/* this structure contains the full arch-specific faultinfo + * from the traps. + * On i386, ptrace_faultinfo unfortunately doesn't provide + * all the info, since trap_no is missing. + * All common elements are defined at the same position in + * both structures, thus making it easy to copy the + * contents without knowledge about the structure elements. + */ +struct faultinfo { + int error_code; /* in ptrace_faultinfo misleadingly called is_write */ + unsigned long cr2; /* in ptrace_faultinfo called addr */ + int trap_no; /* missing in ptrace_faultinfo */ +}; + +#define FAULT_WRITE(fi) ((fi).error_code & 2) +#define FAULT_ADDRESS(fi) ((fi).cr2) + +#define PTRACE_FULL_FAULTINFO 1 + +#endif diff --git a/arch/um/include/sysdep-x86_64/ptrace.h b/arch/um/include/sysdep-x86_64/ptrace.h index 915c82daff..348e8fcd51 100644 --- a/arch/um/include/sysdep-x86_64/ptrace.h +++ b/arch/um/include/sysdep-x86_64/ptrace.h @@ -9,6 +9,7 @@ #include "uml-config.h" #include "user_constants.h" +#include "sysdep/faultinfo.h" #define MAX_REG_OFFSET (UM_FRAME_SIZE) #define MAX_REG_NR ((MAX_REG_OFFSET) / sizeof(unsigned long)) @@ -83,6 +84,7 @@ union uml_pt_regs { long syscall; unsigned long orig_rax; void *sc; + struct faultinfo faultinfo; } tt; #endif #ifdef UML_CONFIG_MODE_SKAS @@ -90,9 +92,7 @@ union uml_pt_regs { /* XXX */ unsigned long regs[27]; unsigned long fp[65]; - unsigned long fault_addr; - unsigned long fault_type; - unsigned long trap_type; + struct faultinfo faultinfo; long syscall; int is_user; } skas; @@ -241,14 +241,8 @@ struct syscall_args { CHOOSE_MODE(SC_SEGV_IS_FIXABLE(UPT_SC(r)), \ REGS_SEGV_IS_FIXABLE(&r->skas)) -#define UPT_FAULT_ADDR(r) \ - __CHOOSE_MODE(SC_FAULT_ADDR(UPT_SC(r)), REGS_FAULT_ADDR(&r->skas)) - -#define UPT_FAULT_WRITE(r) \ - CHOOSE_MODE(SC_FAULT_WRITE(UPT_SC(r)), REGS_FAULT_WRITE(&r->skas)) - -#define UPT_TRAP(r) __CHOOSE_MODE(SC_TRAP_TYPE(UPT_SC(r)), REGS_TRAP(&r->skas)) -#define UPT_ERR(r) __CHOOSE_MODE(SC_FAULT_TYPE(UPT_SC(r)), REGS_ERR(&r->skas)) +#define UPT_FAULTINFO(r) \ + CHOOSE_MODE((&(r)->tt.faultinfo), (&(r)->skas.faultinfo)) #endif diff --git a/arch/um/include/sysdep-x86_64/sigcontext.h b/arch/um/include/sysdep-x86_64/sigcontext.h index 1e38a54ff4..2a78260d15 100644 --- a/arch/um/include/sysdep-x86_64/sigcontext.h +++ b/arch/um/include/sysdep-x86_64/sigcontext.h @@ -17,11 +17,12 @@ #define SC_FAULT_ADDR(sc) SC_CR2(sc) #define SC_FAULT_TYPE(sc) SC_ERR(sc) -#define FAULT_WRITE(err) ((err) & 2) - -#define SC_FAULT_WRITE(sc) FAULT_WRITE(SC_FAULT_TYPE(sc)) - -#define SC_TRAP_TYPE(sc) SC_TRAPNO(sc) +#define GET_FAULTINFO_FROM_SC(fi,sc) \ + { \ + (fi).cr2 = SC_CR2(sc); \ + (fi).error_code = SC_ERR(sc); \ + (fi).trap_no = SC_TRAPNO(sc); \ + } /* ptrace expects that, at the start of a system call, %eax contains * -ENOSYS, so this makes it so. @@ -29,8 +30,8 @@ #define SC_START_SYSCALL(sc) do SC_RAX(sc) = -ENOSYS; while(0) -#define SEGV_IS_FIXABLE(trap) ((trap) == 14) -#define SC_SEGV_IS_FIXABLE(sc) SEGV_IS_FIXABLE(SC_TRAP_TYPE(sc)) +/* This is Page Fault */ +#define SEGV_IS_FIXABLE(fi) ((fi)->trap_no == 14) extern unsigned long *sc_sigmask(void *sc_ptr); diff --git a/arch/um/include/sysdep-x86_64/skas_ptrace.h b/arch/um/include/sysdep-x86_64/skas_ptrace.h new file mode 100644 index 0000000000..95db4be786 --- /dev/null +++ b/arch/um/include/sysdep-x86_64/skas_ptrace.h @@ -0,0 +1,22 @@ +/* + * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com) + * Licensed under the GPL + */ + +#ifndef __SYSDEP_X86_64_SKAS_PTRACE_H +#define __SYSDEP_X86_64_SKAS_PTRACE_H + +struct ptrace_faultinfo { + int is_write; + unsigned long addr; +}; + +struct ptrace_ldt { + int func; + void *ptr; + unsigned long bytecount; +}; + +#define PTRACE_LDT 54 + +#endif diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c index ffc599bd85..ec19fed7c6 100644 --- a/arch/um/kernel/ptrace.c +++ b/arch/um/kernel/ptrace.c @@ -252,13 +252,13 @@ long sys_ptrace(long request, long pid, long addr, long data) break; #endif case PTRACE_FAULTINFO: { - struct ptrace_faultinfo fault; - - fault = ((struct ptrace_faultinfo) - { .is_write = child->thread.err, - .addr = child->thread.cr2 }); - ret = copy_to_user((unsigned long __user *) data, &fault, - sizeof(fault)); + /* Take the info from thread->arch->faultinfo, + * but transfer max. sizeof(struct ptrace_faultinfo). + * On i386, ptrace_faultinfo is smaller! + */ + ret = copy_to_user((unsigned long __user *) data, + &child->thread.arch.faultinfo, + sizeof(struct ptrace_faultinfo)); if(ret) break; break; @@ -269,6 +269,7 @@ long sys_ptrace(long request, long pid, long addr, long data) sizeof(child->pending.signal)); break; +#ifdef PTRACE_LDT case PTRACE_LDT: { struct ptrace_ldt ldt; @@ -284,6 +285,7 @@ long sys_ptrace(long request, long pid, long addr, long data) ret = -EIO; break; } +#endif #ifdef CONFIG_PROC_MM case PTRACE_SWITCH_MM: { struct mm_struct *old = child->mm; diff --git a/arch/um/kernel/skas/include/skas.h b/arch/um/kernel/skas/include/skas.h index f0702c2c72..96b51dba34 100644 --- a/arch/um/kernel/skas/include/skas.h +++ b/arch/um/kernel/skas/include/skas.h @@ -27,9 +27,10 @@ extern void map(int fd, unsigned long virt, unsigned long len, int r, int w, extern int unmap(int fd, void *addr, unsigned long len); extern int protect(int fd, unsigned long addr, unsigned long len, int r, int w, int x); -extern void user_signal(int sig, union uml_pt_regs *regs); +extern void user_signal(int sig, union uml_pt_regs *regs, int pid); extern int new_mm(int from); extern void start_userspace(int cpu); +extern void get_skas_faultinfo(int pid, struct faultinfo * fi); extern long execute_syscall_skas(void *r); #endif diff --git a/arch/um/kernel/skas/process.c b/arch/um/kernel/skas/process.c index b4ffaaa812..c0b30515df 100644 --- a/arch/um/kernel/skas/process.c +++ b/arch/um/kernel/skas/process.c @@ -4,6 +4,7 @@ */ #include +#include #include #include #include @@ -37,17 +38,26 @@ int is_skas_winch(int pid, int fd, void *data) return(1); } -static void handle_segv(int pid) +void get_skas_faultinfo(int pid, struct faultinfo * fi) { - struct ptrace_faultinfo fault; int err; - err = ptrace(PTRACE_FAULTINFO, pid, 0, &fault); + err = ptrace(PTRACE_FAULTINFO, pid, 0, fi); if(err) - panic("handle_segv - PTRACE_FAULTINFO failed, errno = %d\n", - errno); + panic("get_skas_faultinfo - PTRACE_FAULTINFO failed, " + "errno = %d\n", errno); + + /* Special handling for i386, which has different structs */ + if (sizeof(struct ptrace_faultinfo) < sizeof(struct faultinfo)) + memset((char *)fi + sizeof(struct ptrace_faultinfo), 0, + sizeof(struct faultinfo) - + sizeof(struct ptrace_faultinfo)); +} - segv(fault.addr, 0, FAULT_WRITE(fault.is_write), 1, NULL); +static void handle_segv(int pid, union uml_pt_regs * regs) +{ + get_skas_faultinfo(pid, ®s->skas.faultinfo); + segv(regs->skas.faultinfo, 0, 1, NULL); } /*To use the same value of using_sysemu as the caller, ask it that value (in local_using_sysemu)*/ @@ -163,7 +173,7 @@ void userspace(union uml_pt_regs *regs) if(WIFSTOPPED(status)){ switch(WSTOPSIG(status)){ case SIGSEGV: - handle_segv(pid); + handle_segv(pid, regs); break; case SIGTRAP + 0x80: handle_trap(pid, regs, local_using_sysemu); @@ -177,7 +187,7 @@ void userspace(union uml_pt_regs *regs) case SIGBUS: case SIGFPE: case SIGWINCH: - user_signal(WSTOPSIG(status), regs); + user_signal(WSTOPSIG(status), regs, pid); break; default: printk("userspace - child stopped with signal " diff --git a/arch/um/kernel/skas/trap_user.c b/arch/um/kernel/skas/trap_user.c index 8e9b46d470..0dee1d95c8 100644 --- a/arch/um/kernel/skas/trap_user.c +++ b/arch/um/kernel/skas/trap_user.c @@ -5,12 +5,15 @@ #include #include -#include "sysdep/ptrace.h" #include "signal_user.h" #include "user_util.h" #include "kern_util.h" #include "task.h" #include "sigcontext.h" +#include "skas.h" +#include "ptrace_user.h" +#include "sysdep/ptrace.h" +#include "sysdep/ptrace_user.h" void sig_handler_common_skas(int sig, void *sc_ptr) { @@ -31,9 +34,11 @@ void sig_handler_common_skas(int sig, void *sc_ptr) r = &TASK_REGS(get_current())->skas; save_user = r->is_user; r->is_user = 0; - r->fault_addr = SC_FAULT_ADDR(sc); - r->fault_type = SC_FAULT_TYPE(sc); - r->trap_type = SC_TRAP_TYPE(sc); + if ( sig == SIGFPE || sig == SIGSEGV || + sig == SIGBUS || sig == SIGILL || + sig == SIGTRAP ) { + GET_FAULTINFO_FROM_SC(r->faultinfo, sc); + } change_sig(SIGUSR1, 1); info = &sig_info[sig]; @@ -45,14 +50,17 @@ void sig_handler_common_skas(int sig, void *sc_ptr) r->is_user = save_user; } -void user_signal(int sig, union uml_pt_regs *regs) +extern int ptrace_faultinfo; + +void user_signal(int sig, union uml_pt_regs *regs, int pid) { struct signal_info *info; + int segv = ((sig == SIGFPE) || (sig == SIGSEGV) || (sig == SIGBUS) || + (sig == SIGILL) || (sig == SIGTRAP)); regs->skas.is_user = 1; - regs->skas.fault_addr = 0; - regs->skas.fault_type = 0; - regs->skas.trap_type = 0; + if (segv) + get_skas_faultinfo(pid, ®s->skas.faultinfo); info = &sig_info[sig]; (*info->handler)(sig, regs); diff --git a/arch/um/kernel/trap_kern.c b/arch/um/kernel/trap_kern.c index 47e766e6ba..54e2ec33a4 100644 --- a/arch/um/kernel/trap_kern.c +++ b/arch/um/kernel/trap_kern.c @@ -133,12 +133,19 @@ static int check_remapped_addr(unsigned long address, int is_write) return(0); } -unsigned long segv(unsigned long address, unsigned long ip, int is_write, - int is_user, void *sc) +/* + * We give a *copy* of the faultinfo in the regs to segv. + * This must be done, since nesting SEGVs could overwrite + * the info in the regs. A pointer to the info then would + * give us bad data! + */ +unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc) { struct siginfo si; void *catcher; int err; + int is_write = FAULT_WRITE(fi); + unsigned long address = FAULT_ADDRESS(fi); if(!is_user && (address >= start_vm) && (address < end_vm)){ flush_tlb_kernel_vm(); @@ -159,7 +166,7 @@ unsigned long segv(unsigned long address, unsigned long ip, int is_write, } else if(current->thread.fault_addr != NULL) panic("fault_addr set but no fault catcher"); - else if(arch_fixup(ip, sc)) + else if(!is_user && arch_fixup(ip, sc)) return(0); if(!is_user) @@ -171,6 +178,7 @@ unsigned long segv(unsigned long address, unsigned long ip, int is_write, si.si_errno = 0; si.si_code = BUS_ADRERR; si.si_addr = (void *)address; + current->thread.arch.faultinfo = fi; force_sig_info(SIGBUS, &si, current); } else if(err == -ENOMEM){ @@ -180,22 +188,20 @@ unsigned long segv(unsigned long address, unsigned long ip, int is_write, else { si.si_signo = SIGSEGV; si.si_addr = (void *) address; - current->thread.cr2 = address; - current->thread.err = is_write; + current->thread.arch.faultinfo = fi; force_sig_info(SIGSEGV, &si, current); } return(0); } -void bad_segv(unsigned long address, unsigned long ip, int is_write) +void bad_segv(struct faultinfo fi, unsigned long ip) { struct siginfo si; si.si_signo = SIGSEGV; si.si_code = SEGV_ACCERR; - si.si_addr = (void *) address; - current->thread.cr2 = address; - current->thread.err = is_write; + si.si_addr = (void *) FAULT_ADDRESS(fi); + current->thread.arch.faultinfo = fi; force_sig_info(SIGSEGV, &si, current); } @@ -204,6 +210,7 @@ void relay_signal(int sig, union uml_pt_regs *regs) if(arch_handle_signal(sig, regs)) return; if(!UPT_IS_USER(regs)) panic("Kernel mode signal %d", sig); + current->thread.arch.faultinfo = *UPT_FAULTINFO(regs); force_sig(sig, current); } diff --git a/arch/um/kernel/trap_user.c b/arch/um/kernel/trap_user.c index 50a4042a50..f825a6eda3 100644 --- a/arch/um/kernel/trap_user.c +++ b/arch/um/kernel/trap_user.c @@ -54,23 +54,22 @@ struct { void segv_handler(int sig, union uml_pt_regs *regs) { int index, max; + struct faultinfo * fi = UPT_FAULTINFO(regs); - if(UPT_IS_USER(regs) && !UPT_SEGV_IS_FIXABLE(regs)){ - bad_segv(UPT_FAULT_ADDR(regs), UPT_IP(regs), - UPT_FAULT_WRITE(regs)); + if(UPT_IS_USER(regs) && !SEGV_IS_FIXABLE(fi)){ + bad_segv(*fi, UPT_IP(regs)); return; } max = sizeof(segfault_record)/sizeof(segfault_record[0]); index = next_trap_index(max); nsegfaults++; - segfault_record[index].address = UPT_FAULT_ADDR(regs); + segfault_record[index].address = FAULT_ADDRESS(*fi); segfault_record[index].pid = os_getpid(); - segfault_record[index].is_write = UPT_FAULT_WRITE(regs); + segfault_record[index].is_write = FAULT_WRITE(*fi); segfault_record[index].sp = UPT_SP(regs); segfault_record[index].is_user = UPT_IS_USER(regs); - segv(UPT_FAULT_ADDR(regs), UPT_IP(regs), UPT_FAULT_WRITE(regs), - UPT_IS_USER(regs), regs); + segv(*fi, UPT_IP(regs), UPT_IS_USER(regs), regs); } void usr2_handler(int sig, union uml_pt_regs *regs) diff --git a/arch/um/kernel/tt/tracer.c b/arch/um/kernel/tt/tracer.c index 7b5d937e59..f7b1753a02 100644 --- a/arch/um/kernel/tt/tracer.c +++ b/arch/um/kernel/tt/tracer.c @@ -89,8 +89,10 @@ void tracer_panic(char *format, ...) static void tracer_segv(int sig, struct sigcontext sc) { + struct faultinfo fi; + GET_FAULTINFO_FROM_SC(fi, &sc); printf("Tracing thread segfault at address 0x%lx, ip 0x%lx\n", - SC_FAULT_ADDR(&sc), SC_IP(&sc)); + FAULT_ADDRESS(fi), SC_IP(&sc)); while(1) pause(); } diff --git a/arch/um/kernel/tt/trap_user.c b/arch/um/kernel/tt/trap_user.c index 92a3820ca5..fc108615be 100644 --- a/arch/um/kernel/tt/trap_user.c +++ b/arch/um/kernel/tt/trap_user.c @@ -7,6 +7,7 @@ #include #include #include "sysdep/ptrace.h" +#include "sysdep/sigcontext.h" #include "signal_user.h" #include "user_util.h" #include "kern_util.h" @@ -28,6 +29,11 @@ void sig_handler_common_tt(int sig, void *sc_ptr) change_sig(SIGSEGV, 1); r = &TASK_REGS(get_current())->tt; + if ( sig == SIGFPE || sig == SIGSEGV || + sig == SIGBUS || sig == SIGILL || + sig == SIGTRAP ) { + GET_FAULTINFO_FROM_SC(r->faultinfo, sc); + } save_regs = *r; is_user = user_context(SC_SP(sc)); r->sc = sc; diff --git a/arch/um/sys-i386/signal.c b/arch/um/sys-i386/signal.c index 76ba87254b..03913ca5d2 100644 --- a/arch/um/sys-i386/signal.c +++ b/arch/um/sys-i386/signal.c @@ -47,9 +47,6 @@ static int copy_sc_from_user_skas(struct pt_regs *regs, REGS_CS(regs->regs.skas.regs) = sc.cs; REGS_EFLAGS(regs->regs.skas.regs) = sc.eflags; REGS_SS(regs->regs.skas.regs) = sc.ss; - regs->regs.skas.fault_addr = sc.cr2; - regs->regs.skas.fault_type = FAULT_WRITE(sc.err); - regs->regs.skas.trap_type = sc.trapno; err = restore_fp_registers(userspace_pid[0], fpregs); if(err < 0){ @@ -62,11 +59,11 @@ static int copy_sc_from_user_skas(struct pt_regs *regs, } int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp, - struct pt_regs *regs, unsigned long fault_addr, - int fault_type) + struct pt_regs *regs) { struct sigcontext sc; unsigned long fpregs[HOST_FP_SIZE]; + struct faultinfo * fi = ¤t->thread.arch.faultinfo; int err; sc.gs = REGS_GS(regs->regs.skas.regs); @@ -86,9 +83,9 @@ int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp, sc.eflags = REGS_EFLAGS(regs->regs.skas.regs); sc.esp_at_signal = regs->regs.skas.regs[UESP]; sc.ss = regs->regs.skas.regs[SS]; - sc.cr2 = fault_addr; - sc.err = TO_SC_ERR(fault_type); - sc.trapno = regs->regs.skas.trap_type; + sc.cr2 = fi->cr2; + sc.err = fi->error_code; + sc.trapno = fi->trap_no; err = save_fp_registers(userspace_pid[0], fpregs); if(err < 0){ @@ -167,9 +164,7 @@ static int copy_sc_to_user(struct sigcontext *to, struct _fpstate *fp, { return(CHOOSE_MODE(copy_sc_to_user_tt(to, fp, UPT_SC(&from->regs), sizeof(*fp)), - copy_sc_to_user_skas(to, fp, from, - current->thread.cr2, - current->thread.err))); + copy_sc_to_user_skas(to, fp, from))); } static int copy_ucontext_to_user(struct ucontext *uc, struct _fpstate *fp, diff --git a/arch/um/sys-x86_64/signal.c b/arch/um/sys-x86_64/signal.c index 5bc5a0d796..b740177066 100644 --- a/arch/um/sys-x86_64/signal.c +++ b/arch/um/sys-x86_64/signal.c @@ -57,7 +57,7 @@ static int copy_sc_from_user_skas(struct pt_regs *regs, int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp, struct pt_regs *regs, unsigned long mask) { - unsigned long eflags; + struct faultinfo * fi = ¤t->thread.arch.faultinfo; int err = 0; err |= __put_user(0, &to->gs); @@ -84,14 +84,16 @@ int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp, err |= PUTREG(regs, R14, to, r14); err |= PUTREG(regs, R15, to, r15); err |= PUTREG(regs, CS, to, cs); /* XXX x86_64 doesn't do this */ - err |= __put_user(current->thread.err, &to->err); - err |= __put_user(current->thread.trap_no, &to->trapno); + + err |= __put_user(fi->cr2, &to->cr2); + err |= __put_user(fi->error_code, &to->err); + err |= __put_user(fi->trap_no, &to->trapno); + err |= PUTREG(regs, RIP, to, rip); err |= PUTREG(regs, EFLAGS, to, eflags); #undef PUTREG err |= __put_user(mask, &to->oldmask); - err |= __put_user(current->thread.cr2, &to->cr2); return(err); } diff --git a/include/asm-um/processor-generic.h b/include/asm-um/processor-generic.h index b953b1ad3b..b2fc94fbc2 100644 --- a/include/asm-um/processor-generic.h +++ b/include/asm-um/processor-generic.h @@ -24,9 +24,6 @@ struct thread_struct { int forking; int nsyscalls; struct pt_regs regs; - unsigned long cr2; - int err; - unsigned long trap_no; int singlestep_syscall; void *fault_addr; void *fault_catcher; @@ -74,8 +71,6 @@ struct thread_struct { .forking = 0, \ .nsyscalls = 0, \ .regs = EMPTY_REGS, \ - .cr2 = 0, \ - .err = 0, \ .fault_addr = NULL, \ .prev_sched = NULL, \ .temp_stack = 0, \ diff --git a/include/asm-um/processor-i386.h b/include/asm-um/processor-i386.h index 2deb8f1adb..431bad3ae9 100644 --- a/include/asm-um/processor-i386.h +++ b/include/asm-um/processor-i386.h @@ -9,13 +9,18 @@ extern int host_has_xmm; extern int host_has_cmov; +/* include faultinfo structure */ +#include "sysdep/faultinfo.h" + struct arch_thread { unsigned long debugregs[8]; int debugregs_seq; + struct faultinfo faultinfo; }; #define INIT_ARCH_THREAD { .debugregs = { [ 0 ... 7 ] = 0 }, \ - .debugregs_seq = 0 } + .debugregs_seq = 0, \ + .faultinfo = { 0, 0, 0 } } #include "asm/arch/user.h" diff --git a/include/asm-um/processor-x86_64.h b/include/asm-um/processor-x86_64.h index a1ae3a4cd9..0beb9a42ae 100644 --- a/include/asm-um/processor-x86_64.h +++ b/include/asm-um/processor-x86_64.h @@ -7,9 +7,13 @@ #ifndef __UM_PROCESSOR_X86_64_H #define __UM_PROCESSOR_X86_64_H -#include "asm/arch/user.h" +/* include faultinfo structure */ +#include "sysdep/faultinfo.h" struct arch_thread { + unsigned long debugregs[8]; + int debugregs_seq; + struct faultinfo faultinfo; }; /* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */ @@ -20,7 +24,11 @@ extern inline void rep_nop(void) #define cpu_relax() rep_nop() -#define INIT_ARCH_THREAD { } +#define INIT_ARCH_THREAD { .debugregs = { [ 0 ... 7 ] = 0 }, \ + .debugregs_seq = 0, \ + .faultinfo = { 0, 0, 0 } } + +#include "asm/arch/user.h" #define current_text_addr() \ ({ void *pc; __asm__("movq $1f,%0\n1:":"=g" (pc)); pc; })