diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2016-12-20 04:30:05 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-04-28 21:02:25 +1000 |
| commit | c4f3b52ce7b16824befb16ab3d045c891b08b7db (patch) | |
| tree | 92f77ba25144dbe046368583e18e21c83015e642 /arch/powerpc/kernel/traps.c | |
| parent | a3d96f70c14773d0928c6a54fd278138f0868572 (diff) | |
powerpc/64s: Disallow system reset vs system reset reentrancy
In preparation for using a dedicated stack for system reset interrupts,
prevent a nested system reset from recovering, in order to simplify
code that is called in crash/debug path. This allows a system reset
interrupt to just use the base stack pointer.
Keep an in_nmi nesting counter similarly to the in_mce counter. Consider
the interrrupt non-recoverable if it is taken inside another system
reset.
Interrupt nesting could be allowed similarly to MCE, but system reset
is a special case that's not for normal operation, so simplicity wins
until there is requirement for nested system reset interrupts.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/traps.c')
| -rw-r--r-- | arch/powerpc/kernel/traps.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 76f6045b021b..2393d3c46236 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -282,11 +282,17 @@ void system_reset_exception(struct pt_regs *regs) /* See if any machine dependent calls */ if (ppc_md.system_reset_exception) { if (ppc_md.system_reset_exception(regs)) - return; + goto out; } die("System Reset", regs, SIGABRT); +out: +#ifdef CONFIG_PPC_BOOK3S_64 + BUG_ON(get_paca()->in_nmi == 0); + if (get_paca()->in_nmi > 1) + panic("Unrecoverable nested System Reset"); +#endif /* Must die if the interrupt is not recoverable */ if (!(regs->msr & MSR_RI)) panic("Unrecoverable System Reset"); |