Mark Rutland b5e7307d9d arm64: fix dump_backtrace/unwind_frame with NULL tsk ... In some places, dump_backtrace() is called with a NULL tsk parameter, e.g. in bug_handler() in arch/arm64, or indirectly via show_stack() in core code. The expectation is that this is treated as if current were passed instead of NULL. Similar is true of unwind_frame(). Commit a80a0eb70c ("arm64: make irq_stack_ptr more robust") didn't take this into account. In dump_backtrace() it compares tsk against current *before* we check if tsk is NULL, and in unwind_frame() we never set tsk if it is NULL. Due to this, we won't initialise irq_stack_ptr in either function. In dump_backtrace() this results in calling dump_mem() for memory immediately above the IRQ stack range, rather than for the relevant range on the task stack. In unwind_frame we'll reject unwinding frames on the IRQ stack. In either case this results in incomplete or misleading backtrace information, but is not otherwise problematic. The initial percpu areas (including the IRQ stacks) are allocated in the linear map, and dump_mem uses __get_user(), so we shouldn't access anything with side-effects, and will handle holes safely. This patch fixes the issue by having both functions handle the NULL tsk case before doing anything else with tsk. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Fixes: a80a0eb70c ("arm64: make irq_stack_ptr more robust") Acked-by: James Morse <james.morse@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yang Shi <yang.shi@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>		2016-09-26 14:24:01 +01:00
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boot	ARM: SoC fixes	2016-08-11 14:14:23 -07:00
configs	arm64: defconfig: enable CONFIG_LOCALVERSION_AUTO	2016-08-12 19:08:48 +01:00
crypto	Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2016-03-17 11:22:54 -07:00
include	arm/arm64: arch_timer: Use archdata to indicate vdso suitability	2016-09-23 17:19:25 +01:00
kernel	arm64: fix dump_backtrace/unwind_frame with NULL tsk	2016-09-26 14:24:01 +01:00
kvm	arm64/kvm: use alternative auto-nop	2016-09-12 10:46:07 +01:00
lib	arm64: use alternative auto-nop	2016-09-12 10:46:07 +01:00
mm	arm64: migrate exception table users off module.h and onto extable.h	2016-09-20 09:36:21 +01:00
net	arm64: bpf: optimize LD_ABS, LD_IND	2016-06-10 23:11:50 -07:00
xen	arm/xen: add support for vm_assist hypercall	2016-07-06 10:42:14 +01:00
Kconfig	arm/arm64: arch_timer: Use archdata to indicate vdso suitability	2016-09-23 17:19:25 +01:00
Kconfig.debug	arm64: always enable DEBUG_RODATA and remove the Kconfig option	2016-08-26 10:13:41 +01:00
Kconfig.platforms	arm64: remove redundant "select HAVE_CLK"	2016-08-22 10:00:48 +01:00
Makefile	arm64: Set UTS_MACHINE in the Makefile	2016-08-31 12:31:38 +01:00