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77e02cf57b
The boot-time allocation interface for memblock is a mess, with
'memblock_alloc()' returning a virtual pointer, but then you are
supposed to free it with 'memblock_free()' that takes a _physical_
address.
Not only is that all kinds of strange and illogical, but it actually
causes bugs, when people then use it like a normal allocation function,
and it fails spectacularly on a NULL pointer:
https://lore.kernel.org/all/20210912140820.GD25450@xsang-OptiPlex-9020/
or just random memory corruption if the debug checks don't catch it:
https://lore.kernel.org/all/61ab2d0c-3313-aaab-514c-e15b7aa054a0@suse.cz/
I really don't want to apply patches that treat the symptoms, when the
fundamental cause is this horribly confusing interface.
I started out looking at just automating a sane replacement sequence,
but because of this mix or virtual and physical addresses, and because
people have used the "__pa()" macro that can take either a regular
kernel pointer, or just the raw "unsigned long" address, it's all quite
messy.
So this just introduces a new saner interface for freeing a virtual
address that was allocated using 'memblock_alloc()', and that was kept
as a regular kernel pointer. And then it converts a couple of users
that are obvious and easy to test, including the 'xbc_nodes' case in
lib/bootconfig.c that caused problems.
Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes:
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.. | ||
firmware_loader | ||
power | ||
regmap | ||
test | ||
arch_numa.c | ||
arch_topology.c | ||
attribute_container.c | ||
auxiliary.c | ||
base.h | ||
bus.c | ||
cacheinfo.c | ||
class.c | ||
component.c | ||
container.c | ||
core.c | ||
cpu.c | ||
dd.c | ||
devcoredump.c | ||
devres.c | ||
devtmpfs.c | ||
driver.c | ||
firmware.c | ||
hypervisor.c | ||
init.c | ||
isa.c | ||
Kconfig | ||
Makefile | ||
map.c | ||
memory.c | ||
module.c | ||
node.c | ||
pinctrl.c | ||
platform-msi.c | ||
platform.c | ||
property.c | ||
soc.c | ||
swnode.c | ||
syscore.c | ||
topology.c | ||
trace.c | ||
trace.h | ||
transport_class.c |