From 377fad3acbb7e94ab9942a74e0d9ede8eeb2f039 Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Sun, 6 May 2007 14:51:25 -0700 Subject: uml: kernel segfaults should dump proper registers If there's a segfault inside the kernel, we want a dump of the registers at the point of the segfault, not the registers at the point of calling panic or the last userspace registers. sig_handler_common_skas now uses a static register set in the case of a SIGSEGV to avoid messing up the process registers if the segfault turns out to be non-fatal. The architecture sigcontext-to-pt_regs copying code was repurposed to copy data out of the SEGV stack frame. Signed-off-by: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/sys-i386/signal.c | 41 ++++++++++++++++++++++++----------------- 1 file changed, 24 insertions(+), 17 deletions(-) (limited to 'arch/um/sys-i386') diff --git a/arch/um/sys-i386/signal.c b/arch/um/sys-i386/signal.c index 42ecf8e8ad08..1cbf95f6858a 100644 --- a/arch/um/sys-i386/signal.c +++ b/arch/um/sys-i386/signal.c @@ -18,6 +18,28 @@ #include "skas.h" +void copy_sc(union uml_pt_regs *regs, void *from) +{ + struct sigcontext *sc = from; + + REGS_GS(regs->skas.regs) = sc->gs; + REGS_FS(regs->skas.regs) = sc->fs; + REGS_ES(regs->skas.regs) = sc->es; + REGS_DS(regs->skas.regs) = sc->ds; + REGS_EDI(regs->skas.regs) = sc->edi; + REGS_ESI(regs->skas.regs) = sc->esi; + REGS_EBP(regs->skas.regs) = sc->ebp; + REGS_SP(regs->skas.regs) = sc->esp; + REGS_EBX(regs->skas.regs) = sc->ebx; + REGS_EDX(regs->skas.regs) = sc->edx; + REGS_ECX(regs->skas.regs) = sc->ecx; + REGS_EAX(regs->skas.regs) = sc->eax; + REGS_IP(regs->skas.regs) = sc->eip; + REGS_CS(regs->skas.regs) = sc->cs; + REGS_EFLAGS(regs->skas.regs) = sc->eflags; + REGS_SS(regs->skas.regs) = sc->ss; +} + static int copy_sc_from_user_skas(struct pt_regs *regs, struct sigcontext __user *from) { @@ -30,25 +52,10 @@ static int copy_sc_from_user_skas(struct pt_regs *regs, if(err) return err; - REGS_GS(regs->regs.skas.regs) = sc.gs; - REGS_FS(regs->regs.skas.regs) = sc.fs; - REGS_ES(regs->regs.skas.regs) = sc.es; - REGS_DS(regs->regs.skas.regs) = sc.ds; - REGS_EDI(regs->regs.skas.regs) = sc.edi; - REGS_ESI(regs->regs.skas.regs) = sc.esi; - REGS_EBP(regs->regs.skas.regs) = sc.ebp; - REGS_SP(regs->regs.skas.regs) = sc.esp; - REGS_EBX(regs->regs.skas.regs) = sc.ebx; - REGS_EDX(regs->regs.skas.regs) = sc.edx; - REGS_ECX(regs->regs.skas.regs) = sc.ecx; - REGS_EAX(regs->regs.skas.regs) = sc.eax; - REGS_IP(regs->regs.skas.regs) = sc.eip; - REGS_CS(regs->regs.skas.regs) = sc.cs; - REGS_EFLAGS(regs->regs.skas.regs) = sc.eflags; - REGS_SS(regs->regs.skas.regs) = sc.ss; + copy_sc(®s->regs, &sc); err = restore_fp_registers(userspace_pid[0], fpregs); - if(err < 0){ + if(err < 0) { printk("copy_sc_from_user_skas - PTRACE_SETFPREGS failed, " "errno = %d\n", -err); return err; -- cgit v1.2.3