From c578455a3eccf4dd7bd111e77129c301d6d67914 Mon Sep 17 00:00:00 2001 From: Bodo Stroesser Date: Thu, 5 May 2005 16:15:31 -0700 Subject: [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 --- arch/um/kernel/trap_kern.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) (limited to 'arch/um/kernel/trap_kern.c') diff --git a/arch/um/kernel/trap_kern.c b/arch/um/kernel/trap_kern.c index 47e766e6ba10..54e2ec33a43c 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); } -- cgit v1.2.3-55-g7522