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5352090a99
Disable address sanitization for raw and non-maskable interrupt handlers, because they can run in real mode, where we cannot access the shadow memory. (Note that kasan_arch_is_ready() doesn't test for real mode, since it is a static branch for speed, and in any case not all the entry points to the generic KASAN code are protected by kasan_arch_is_ready guards.) The changes to interrupt_nmi_enter/exit_prepare() look larger than they actually are. The changes are equivalent to adding !IS_ENABLED(CONFIG_KASAN) to the conditions for calling nmi_enter() or nmi_exit() in real mode. That is, the code is equivalent to using the following condition for calling nmi_enter/exit: if (((!IS_ENABLED(CONFIG_PPC_BOOK3S_64) || !firmware_has_feature(FW_FEATURE_LPAR) || radix_enabled()) && !IS_ENABLED(CONFIG_KASAN) || (mfmsr() & MSR_DR)) That unwieldy condition has been split into several statements with comments, for easier reading. The nmi_ipi_lock functions that call atomic functions (i.e., nmi_ipi_lock_start(), nmi_ipi_lock() and nmi_ipi_unlock()), besides being marked noinstr, now call arch_atomic_* functions instead of atomic_* functions because with KASAN enabled, the atomic_* functions are wrappers which explicitly do address sanitization on their arguments. Since we are trying to avoid address sanitization, we have to use the lower-level arch_atomic_* versions. In hv_nmi_check_nonrecoverable(), the regs_set_unrecoverable() call has been open-coded so as to avoid having to either trust the inlining or mark regs_set_unrecoverable() as noinstr. [paulus@ozlabs.org: combined a few work-in-progress commits of Daniel's and wrote the commit message.] Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/YoTFGaKM8Pd46PIK@cleo
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 Restructured Text 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.