Commit 2102a65e authored Jul 28, 2011 by Dave Martin Committed by Russell King Aug 09, 2011

ARM: 7008/1: alignment: Make SIGBUS sent to userspace POSIXly correct



With the UM_SIGNAL alignment fault mode, no siginfo structure is
passed to userspace.

POSIX specifies how siginfo_t should be populated for alignment
faults, so this patch does just that:

  * si_signo = SIGBUS
  * si_code = BUS_ADRALN
  * si_addr = misaligned data address at which access was attempted

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

parent 088c01f1

arch/arm/mm/alignment.c

+11 −3

Original line number	Diff line number	Diff line
		@@ -22,6 +22,7 @@
		#include <linux/sched.h>
		#include <linux/uaccess.h>

		#include <asm/system.h>
		#include <asm/unaligned.h>

		#include "fault.h"
		@@ -913,9 +914,16 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
		if (ai_usermode & UM_FIXUP)
		goto fixup;

		if (ai_usermode & UM_SIGNAL)
		force_sig(SIGBUS, current);
		else {
		if (ai_usermode & UM_SIGNAL) {
		siginfo_t si;

		si.si_signo = SIGBUS;
		si.si_errno = 0;
		si.si_code = BUS_ADRALN;
		si.si_addr = (void __user *)addr;

		force_sig_info(si.si_signo, &si, current);
		} else {
		/*
		* We're about to disable the alignment trap and return to
		* user space. But if an interrupt occurs before actually