377fad3acb
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 <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
84 lines
2.0 KiB
C
84 lines
2.0 KiB
C
/*
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* Copyright (C) 2002 - 2003 Jeff Dike (jdike@addtoit.com)
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* Licensed under the GPL
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*/
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#include <signal.h>
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#include <errno.h>
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#include "kern_util.h"
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#include "as-layout.h"
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#include "task.h"
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#include "sigcontext.h"
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#include "skas.h"
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#include "ptrace_user.h"
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#include "sysdep/ptrace.h"
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#include "sysdep/ptrace_user.h"
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#include "os.h"
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static union uml_pt_regs ksig_regs[UM_NR_CPUS];
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void sig_handler_common_skas(int sig, void *sc_ptr)
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{
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struct sigcontext *sc = sc_ptr;
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union uml_pt_regs *r;
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void (*handler)(int, union uml_pt_regs *);
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int save_user, save_errno = errno;
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/* This is done because to allow SIGSEGV to be delivered inside a SEGV
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* handler. This can happen in copy_user, and if SEGV is disabled,
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* the process will die.
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* XXX Figure out why this is better than SA_NODEFER
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*/
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if(sig == SIGSEGV) {
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change_sig(SIGSEGV, 1);
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/* For segfaults, we want the data from the
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* sigcontext. In this case, we don't want to mangle
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* the process registers, so use a static set of
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* registers. For other signals, the process
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* registers are OK.
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*/
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r = &ksig_regs[cpu()];
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copy_sc(r, sc_ptr);
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}
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else r = TASK_REGS(get_current());
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save_user = r->skas.is_user;
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r->skas.is_user = 0;
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if ( sig == SIGFPE || sig == SIGSEGV ||
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sig == SIGBUS || sig == SIGILL ||
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sig == SIGTRAP ) {
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GET_FAULTINFO_FROM_SC(r->skas.faultinfo, sc);
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}
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change_sig(SIGUSR1, 1);
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handler = sig_info[sig];
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/* unblock SIGALRM, SIGVTALRM, SIGIO if sig isn't IRQ signal */
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if (sig != SIGIO && sig != SIGWINCH &&
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sig != SIGVTALRM && sig != SIGALRM)
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unblock_signals();
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handler(sig, r);
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errno = save_errno;
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r->skas.is_user = save_user;
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}
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extern int ptrace_faultinfo;
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void user_signal(int sig, union uml_pt_regs *regs, int pid)
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{
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void (*handler)(int, union uml_pt_regs *);
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int segv = ((sig == SIGFPE) || (sig == SIGSEGV) || (sig == SIGBUS) ||
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(sig == SIGILL) || (sig == SIGTRAP));
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if (segv)
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get_skas_faultinfo(pid, ®s->skas.faultinfo);
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handler = sig_info[sig];
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handler(sig, (union uml_pt_regs *) regs);
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unblock_signals();
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}
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