kernel.git/arch/powerpc/kernel/traps.c, branch linux-2.6.18.y

[PATCH] POWERPC: Make alignment exception always check exception table

2006-11-19T03:27:58Z

The alignment exception used to only check the exception table for -EFAULT, not for other errors. That opens an oops window if we can coerce the kernel into getting an alignment exception for other reasons in what would normally be a user-protected accessor, which can be done via some of the futex ops. This fixes it by always checking the exception tables. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras Signed-off-by: Chris Wright

Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

2006-08-24T04:08:12Z

[POWERPC] Correct masks used in emulating some instructions

2006-08-23T06:58:39Z

When we get an illegal instruction exception, we check to see whether the instruction is one that we emulate for the user program. Some of the masks we use in checking whether the offending instruction is one we care about didn't have the top bit set, which is the MSB of the major opcode. Thus some undefined opcodes could get emulated as other (defined but unimplemented) instructions. This corrects the masks. Signed-off-by: Paul Mackerras

Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

2006-08-18T16:20:04Z

[POWERPC] Make crash.c work on 32-bit and 64-bit

2006-08-17T06:41:10Z

To compile kexec on 32-bit we need a few more bits and pieces. Rather than add empty definitions, we can make crash.c work on 32-bit, with only a couple of kludges. Signed-off-by: Michael Ellerman Signed-off-by: Paul Mackerras

[POWERPC] Make secondary CPUs call into kdump on reset exception

2006-08-17T06:41:10Z

In the case of a system hang, the user will invoke soft-reset to initiate the kdump boot. If xmon is enabled, the CPU(s) enter into the xmon debugger. Unfortunately, the secondary CPU(s) will return to the hung state when they exit from the debugger (returned from die() -> system_reset_exception()). This causes a problem in kdump since the hung CPU(s) will not respond to the IPI sent from kdump. This patch fixes the issue by calling crash_kexec_secondary() directly from system_reset_exception() without returning to the previous state. These secondary CPUs wait 5ms until the kdump boot is started by the primary CPU. In the case we exited from the debugger to "recover" (command 'x' in xmon) the primary and the secondary CPUs will all return from die() -> system_reset_exception() ->crash_kexec_secondary() wait 5ms, then return to the previous state. A kdump boot is not started in this case. Signed-off-by: Haren Myneni Signed-off-by: David Wilder Signed-off-by: Paul Mackerras

[PATCH] Change panic_on_oops message to "Fatal exception"

2006-08-14T19:54:29Z

Previously the message was "Fatal exception: panic_on_oops", as introduced in a recent patch whith removed a somewhat dangerous call to ssleep() in the panic_on_oops path. However, Paul Mackerras suggested that this was somewhat confusing, leadind people to believe that it was panic_on_oops that was the root cause of the fatal exception. On his suggestion, this patch changes the message to simply "Fatal exception". A suitable oops message should already have been displayed. Signed-off-by: Simon Horman Cc: Paul Mackerras Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

[PATCH] panic_on_oops: remove ssleep()

2006-07-31T20:28:39Z

This patch is part of an effort to unify the panic_on_oops behaviour across all architectures that implement it. It was pointed out to me by Andi Kleen that if an oops has occured in interrupt context, then calling sleep() in the oops path will only cause a panic, and that it would be really better for it not to be in the path at all. This patch removes the ssleep() call and reworks the console message accordinly. I have a slght concern that the resulting console message is too long, feedback welcome. For powerpc it also unifies the 32bit and 64bit behaviour. Fror x86_64, this patch only updates the console message, as ssleep() is already not present. Signed-off-by: Horms Acked-by: Paul Mackerras Cc: Russell King Cc: "Luck, Tony" Cc: Andi Kleen Cc: Chris Zankel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Remove obsolete #include

2006-06-30T17:25:36Z

Signed-off-by: Jörn Engel Signed-off-by: Adrian Bunk

[POWERPC] Add the use of the firmware soft-reset-nmi to kdump.

2006-06-28T05:18:52Z

With this patch, kdump uses the firmware soft-reset NMI for two purposes: 1) Initiate the kdump (take a crash dump) by issuing a soft-reset. 2) Break a CPU out of a deadlock condition that is detected during kdump processing. When a soft-reset is initiated each CPU will enter system_reset_exception() and set its corresponding bit in the global bit-array cpus_in_sr then call die(). When die() finds the CPU's bit set in cpu_in_sr crash_kexec() is called to initiate a crash dump. The first CPU to enter crash_kexec() is called the "crashing CPU". All other CPUs are "secondary CPUs". The secondary CPU's pass through to crash_kexec_secondary() and sleep. The crashing CPU waits for all CPUs to enter via soft-reset then boots the kdump kernel (see crash_soft_reset_check()) When the system crashes due to a panic or exception, crash_kexec() is called by panic() or die(). The crashing CPU sends an IPI to all other CPUs to notify them of the pending shutdown. If a CPU is in a deadlock or hung state with interrupts disabled, the IPI will not be delivered. The result being, that the kdump kernel is not booted. This problem is solved with the use of a firmware generated soft-reset. After the crashing_cpu has issued the IPI, it waits for 10 sec for all CPUs to enter crash_ipi_callback(). A CPU signifies its entry to crash_ipi_callback() by setting its corresponding bit in the cpus_in_crash bit array. After 10 sec, if one or more CPUs have not set their bit in cpus_in_crash we assume that the CPU(s) is deadlocked. The operator is then prompted to generate a soft-reset to break the deadlock. Each CPU enters the soft reset handler as described above. Two conditions must be handled at this point: 1) The system crashed because the operator generated a soft-reset. See 2) The system had crashed before the soft-reset was generated ( in the case of a Panic or oops). The first CPU to enter crash_kexec() uses the state of the kexec_lock to determine this state. If kexec_lock is already held then condition 2 is true and crash_kexec_secondary() is called, else; this CPU is flagged as the crashing CPU, the kexec_lock is acquired and crash_kexec() proceeds as described above. Each additional CPUs responding to the soft-reset will pass through crash_kexec() to kexec_secondary(). All secondary CPUs call crash_ipi_callback() readying them self's for the shutdown. When ready they clear their bit in cpus_in_sr. The crashing CPU waits in kexec_secondary() until all other CPUs have cleared their bits in cpus_in_sr. The kexec kernel boot is then started. Signed-off-by: Haren Myneni Signed-off-by: David Wilder Signed-off-by: Paul Mackerras