arch/x86/kernel-stacks.rst

1 .. SPDX-License-Identifier: GPL-2.0
7 Kernel stacks on x86-64 bit
15 active thread.  These thread stacks are THREAD_SIZE (4*PAGE_SIZE) big.
23 specialized stacks contain no useful data.  The main CPU stacks are:
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
63 stack size allocated to an IST assumes no nesting for the same code.
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>:
125 If it fits into the frame pointer chain, we print it without a question
128 If the address does not fit into our expected frame pointer chain we
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
139 entries), regardless of whether the frame pointer was set up correctly
140 or not - but in most cases we'll get the call chain right as well. The
147 we still print out the real call chain as well - just with more question