arch/x86/kernel-stacks.rst

1 .. SPDX-License-Identifier: GPL-2.0
7 Kernel stacks on x86-64 bit
10 Most of the text from Keith Owens, hacked by AK
37 per CPU interrupt nest counter. This is needed because x86-64 "IST"
48 An IST is selected by a non-zero value in the IST field of an
49 interrupt-gate descriptor.  When an interrupt occurs and the hardware
53 will switch back to the per-thread stack.  If software wants to allow
62 IST events with the same code to be nested.  However in most cases, the
70   Used for interrupt 8 - Double Fault Exception (#DF).
79   Used for non-maskable interrupts (NMI).
102   Used for interrupt 18 - Machine Check Exception (#MC).
119 Adapted from Ingo's mail, Message-ID: <20150521101614.GA10889@gmail.com>:
131  - either the address is not part of the call chain: it's just stale
135  - or it is part of the call chain, but the frame pointer was not set
140 or not - but in most cases we'll get the call chain right as well. The
144 The most important property of this method is that we _never_ lose
147 we still print out the real call chain as well - just with more question
151        the right order, and try to cross from one stack into another
152        reconstructing the call chain. This works most of the time.