4ccae23609
Erhard reported that kmemleak was showing a warning at boot: kmemleak: Not scanning unknown object at 0xc00000007f000000 CPU: 0 PID: 0 Comm: swapper Not tainted 5.19.0-rc3-PMacG5+ #2 Call Trace: .dump_stack_lvl+0x7c/0xc4 (unreliable) .kmemleak_no_scan+0xe0/0x100 .iommu_init_early_dart+0x2f0/0x924 .pmac_probe+0x1b0/0x20c .setup_arch+0x1b8/0x674 .start_kernel+0xdc/0xb74 start_here_common+0x1c/0x44 DART table allocated at: (____ptrval____) Which he bisected to a change in kmemleak, commit 23c2d497de21 ("mm: kmemleak: take a full lowmem check in kmemleak_*_phys()"). Because pmac_probe() is called before mem_topology_setup(), the min/ max PFN variables are still zero. That causes kmemleak_alloc_phys() to ignore the allocation, because the checks against the PFN fail. Then kmemleak_no_scan() can't find the allocation and prints warning. Given that kmemleak_alloc_phys() is ignoring the allocation to begin with, there's no need to call kmemleak_no_scan() at all, which avoids the warning. Reported-by: Erhard Furtner <erhard_f@mailbox.org> Closes: https://lore.kernel.org/all/bug-216156-206035@https.bugzilla.kernel.org%2F/ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240419115913.3317575-1-mpe@ellerman.id.au
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.