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Christophe Leroy 1d8f739b07 powerpc/kuap: Fix set direction in allow/prevent_user_access()
__builtin_constant_p() always return 0 for pointers, so on RADIX
we always end up opening both direction (by writing 0 in SPR29):

  0000000000000170 <._copy_to_user>:
  ...
   1b0:	4c 00 01 2c 	isync
   1b4:	39 20 00 00 	li      r9,0
   1b8:	7d 3d 03 a6 	mtspr   29,r9
   1bc:	4c 00 01 2c 	isync
   1c0:	48 00 00 01 	bl      1c0 <._copy_to_user+0x50>
  			1c0: R_PPC64_REL24	.__copy_tofrom_user
  ...
  0000000000000220 <._copy_from_user>:
  ...
   2ac:	4c 00 01 2c 	isync
   2b0:	39 20 00 00 	li      r9,0
   2b4:	7d 3d 03 a6 	mtspr   29,r9
   2b8:	4c 00 01 2c 	isync
   2bc:	7f c5 f3 78 	mr      r5,r30
   2c0:	7f 83 e3 78 	mr      r3,r28
   2c4:	48 00 00 01 	bl      2c4 <._copy_from_user+0xa4>
  			2c4: R_PPC64_REL24	.__copy_tofrom_user
  ...

Use an explicit parameter for direction selection, so that GCC
is able to see it is a constant:

  00000000000001b0 <._copy_to_user>:
  ...
   1f0:	4c 00 01 2c 	isync
   1f4:	3d 20 40 00 	lis     r9,16384
   1f8:	79 29 07 c6 	rldicr  r9,r9,32,31
   1fc:	7d 3d 03 a6 	mtspr   29,r9
   200:	4c 00 01 2c 	isync
   204:	48 00 00 01 	bl      204 <._copy_to_user+0x54>
  			204: R_PPC64_REL24	.__copy_tofrom_user
  ...
  0000000000000260 <._copy_from_user>:
  ...
   2ec:	4c 00 01 2c 	isync
   2f0:	39 20 ff ff 	li      r9,-1
   2f4:	79 29 00 04 	rldicr  r9,r9,0,0
   2f8:	7d 3d 03 a6 	mtspr   29,r9
   2fc:	4c 00 01 2c 	isync
   300:	7f c5 f3 78 	mr      r5,r30
   304:	7f 83 e3 78 	mr      r3,r28
   308:	48 00 00 01 	bl      308 <._copy_from_user+0xa8>
  			308: R_PPC64_REL24	.__copy_tofrom_user
  ...

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Spell out the directions, s/KUAP_R/KUAP_READ/ etc.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f4e88ec4941d5facb35ce75026b0112f980086c3.1579866752.git.christophe.leroy@c-s.fr
2020-01-28 23:13:44 +11:00
arch powerpc/kuap: Fix set direction in allow/prevent_user_access() 2020-01-28 23:13:44 +11:00
block block: fix an integer overflow in logical block size 2020-01-15 21:43:09 -07:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto tpmdd fixes for Linux v5.5-rc3 2019-12-18 17:17:36 -08:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-01-19 12:03:53 -08:00
drivers Changes for Linus for -rc8. 2020-01-22 12:56:19 -08:00
fs readdir: make user_access_begin() use the real access range 2020-01-23 10:15:28 -08:00
include io_uring-5.5-2020-01-22 2020-01-22 08:30:09 -08:00
init mm, debug_pagealloc: don't rely on static keys too early 2020-01-13 18:19:02 -08:00
ipc treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-01-19 12:03:53 -08:00
lib lib/vdso: Make __cvdso_clock_getres() static 2020-01-10 19:29:01 +01:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm: memcg/slab: call flush_memcg_workqueue() only if memcg workqueue is valid 2020-01-13 18:19:02 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-01-19 12:03:53 -08:00
samples samples/seccomp: Zero out members based on seccomp_notif_sizes 2020-01-02 13:03:39 -08:00
scripts Kbuild fixes for v5.5 (2nd) 2020-01-03 11:21:25 -08:00
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usr gen_initramfs_list.sh: fix 'bad variable name' error 2020-01-04 00:00:48 +09:00
virt PPC KVM fix for 5.5 2019-12-22 13:18:15 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
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.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore modpost: dump missing namespaces into a single modules.nsdeps file 2019-11-11 20:10:01 +09:00
.mailmap MAINTAINERS: update my email address 2020-01-11 14:33:39 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Linux 5.4-rc4 2019-10-29 04:43:29 -06:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-01-19 12:03:53 -08:00
Makefile Linux 5.5-rc7 2020-01-19 16:02:49 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.