Revision cde6901b7b69557a6f90f3183f76eda581af015e authored by Shaddy Baddah on 28 November 2008, 06:10:45 UTC, committed by John W. Linville on 05 December 2008, 14:18:35 UTC
Under my 2.6.28-rc6 sparc64, when associating to an AP through my zd1211rw device, I was seeing kernel log messages like (not exact output): Kernel unaligned access at TPC[10129b68] zd_mac_rx+0x144/0x32c [zd1211rw] For the zd1211rw module, on RX, the 80211 packet will be located after the PLCP header in the skb data buffer. The PLCP header being 5 bytes long, the 80211 header will start unaligned from an aligned skb buffer. As per Documentation/unaligned-memory-access.txt, we must replace the not unaligned() safe compare_ether_addr() with memcmp() to protect architectures that require alignment. Signed-off-by: Shaddy Baddah <shaddy_baddah@hotmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
1 parent 5cf12e8
syscall.c
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <asm/syscall.h>
static int collect_syscall(struct task_struct *target, long *callno,
unsigned long args[6], unsigned int maxargs,
unsigned long *sp, unsigned long *pc)
{
struct pt_regs *regs = task_pt_regs(target);
if (unlikely(!regs))
return -EAGAIN;
*sp = user_stack_pointer(regs);
*pc = instruction_pointer(regs);
*callno = syscall_get_nr(target, regs);
if (*callno != -1L && maxargs > 0)
syscall_get_arguments(target, regs, 0, maxargs, args);
return 0;
}
/**
* task_current_syscall - Discover what a blocked task is doing.
* @target: thread to examine
* @callno: filled with system call number or -1
* @args: filled with @maxargs system call arguments
* @maxargs: number of elements in @args to fill
* @sp: filled with user stack pointer
* @pc: filled with user PC
*
* If @target is blocked in a system call, returns zero with *@callno
* set to the the call's number and @args filled in with its arguments.
* Registers not used for system call arguments may not be available and
* it is not kosher to use &struct user_regset calls while the system
* call is still in progress. Note we may get this result if @target
* has finished its system call but not yet returned to user mode, such
* as when it's stopped for signal handling or syscall exit tracing.
*
* If @target is blocked in the kernel during a fault or exception,
* returns zero with *@callno set to -1 and does not fill in @args.
* If so, it's now safe to examine @target using &struct user_regset
* get() calls as long as we're sure @target won't return to user mode.
*
* Returns -%EAGAIN if @target does not remain blocked.
*
* Returns -%EINVAL if @maxargs is too large (maximum is six).
*/
int task_current_syscall(struct task_struct *target, long *callno,
unsigned long args[6], unsigned int maxargs,
unsigned long *sp, unsigned long *pc)
{
long state;
unsigned long ncsw;
if (unlikely(maxargs > 6))
return -EINVAL;
if (target == current)
return collect_syscall(target, callno, args, maxargs, sp, pc);
state = target->state;
if (unlikely(!state))
return -EAGAIN;
ncsw = wait_task_inactive(target, state);
if (unlikely(!ncsw) ||
unlikely(collect_syscall(target, callno, args, maxargs, sp, pc)) ||
unlikely(wait_task_inactive(target, state) != ncsw))
return -EAGAIN;
return 0;
}
EXPORT_SYMBOL_GPL(task_current_syscall);
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