6bf752daca
This patch implements CONFIG_DEBUG_VIRTUAL to warn about incorrect use of virt_to_phys() and page_to_phys() Below is the result of test_debug_virtual: [ 1.438746] WARNING: CPU: 0 PID: 1 at ./arch/powerpc/include/asm/io.h:808 test_debug_virtual_init+0x3c/0xd4 [ 1.448156] CPU: 0 PID: 1 Comm: swapper Not tainted 4.20.0-rc5-00560-g6bfb52e23a00-dirty #532 [ 1.457259] NIP: c066c550 LR: c0650ccc CTR: c066c514 [ 1.462257] REGS: c900bdb0 TRAP: 0700 Not tainted (4.20.0-rc5-00560-g6bfb52e23a00-dirty) [ 1.471184] MSR: 00029032 <EE,ME,IR,DR,RI> CR: 48000422 XER: 20000000 [ 1.477811] [ 1.477811] GPR00: c0650ccc c900be60 c60d0000 00000000 006000c0 c9000000 00009032 c7fa0020 [ 1.477811] GPR08: 00002400 00000001 09000000 00000000 c07b5d04 00000000 c00037d8 00000000 [ 1.477811] GPR16: 00000000 00000000 00000000 00000000 c0760000 c0740000 00000092 c0685bb0 [ 1.477811] GPR24: c065042c c068a734 c0685b8c 00000006 00000000 c0760000 c075c3c0 ffffffff [ 1.512711] NIP [c066c550] test_debug_virtual_init+0x3c/0xd4 [ 1.518315] LR [c0650ccc] do_one_initcall+0x8c/0x1cc [ 1.523163] Call Trace: [ 1.525595] [c900be60] [c0567340] 0xc0567340 (unreliable) [ 1.530954] [c900be90] [c0650ccc] do_one_initcall+0x8c/0x1cc [ 1.536551] [c900bef0] [c0651000] kernel_init_freeable+0x1f4/0x2cc [ 1.542658] [c900bf30] [c00037ec] kernel_init+0x14/0x110 [ 1.547913] [c900bf40] [c000e1d0] ret_from_kernel_thread+0x14/0x1c [ 1.553971] Instruction dump: [ 1.556909] 3ca50100 bfa10024 54a5000e 3fa0c076 7c0802a6 3d454000 813dc204 554893be [ 1.564566] 7d294010 7d294910 90010034 39290001 <0f090000> 7c3e0b78 955e0008 3fe0c062 [ 1.572425] ---[ end trace 6f6984225b280ad6 ]--- [ 1.577467] PA: 0x09000000 for VA: 0xc9000000 [ 1.581799] PA: 0x061e8f50 for VA: 0xc61e8f50 Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <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 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.