linux.git/init, branch v5.5-rc5

Revert "fs: remove ksys_dup()"

2020-01-03T00:15:33+00:00

This reverts commit 8243186f0cc7 ("fs: remove ksys_dup()") and the
subsequent fix for it in commit 2d3145f8d280 ("early init: fix error
handling when opening /dev/console").

Trying to use filp_open() and f_dupfd() instead of pseudo-syscalls
caused more trouble than what is worth it: it requires accessing vfs
internals and it turns out there were other bugs in it too.

In particular, the file reference counting was wrong - because unlike
the original "open+2*dup" sequence it used "filp_open+3*f_dupfd" and
thus had an extra leaked file reference.

That in turn then caused odd problems with Androidx86 long after boot
becaue of how the extra reference to the console kept the session active
even after all file descriptors had been closed.

Reported-by: youling 257 
Cc: Arvind Sankar 
Cc: Al Viro 
Signed-off-by: Dominik Brodowski 
Signed-off-by: Linus Torvalds

early init: fix error handling when opening /dev/console

2019-12-17T21:10:11+00:00

The comment says "this should never fail", but it definitely can fail
when you have odd initial boot filesystems, or kernel configurations.

So get the error handling right: filp_open() returns an error pointer.

Reported-by: Jesse Barnes 
Reported-by: youling 257 
Fixes: 8243186f0cc7 ("fs: remove ksys_dup()")
Cc: Dominik Brodowski 
Signed-off-by: Linus Torvalds

Fix root mounting with no mount options

2019-12-16T16:42:39+00:00

The "trivial conversion" in commit cccaa5e33525 ("init: use do_mount()
instead of ksys_mount()") was totally broken, since it didn't handle the
case of a NULL mount data pointer.  And while I had "tested" it (and
presumably Dominik had too) that bug was hidden by me having options.

Cc: Dominik Brodowski 
Cc: Arnd Bergmann 
Reported-by: Ondřej Jirman 
Reported-by: Guenter Roeck 
Reported-by: Naresh Kamboju 
Reported-and-tested-by: Borislav Petkov 
Tested-by: Chris Clayton 
Tested-by: Eric Biggers 
Tested-by: Geert Uytterhoeven 
Tested-by: Guido Günther 
Signed-off-by: Linus Torvalds

fs: remove ksys_dup()

2019-12-12T18:00:36+00:00

ksys_dup() is used only at one place in the kernel, namely to duplicate
fd 0 of /dev/console to stdout and stderr. The same functionality can be
achieved by using functions already available within the kernel namespace.

Signed-off-by: Dominik Brodowski

init: unify opening /dev/console as stdin/stdout/stderr

2019-12-12T17:58:24+00:00

Merge the two instances where /dev/console is opened as
stdin/stdout/stderr.

Signed-off-by: Dominik Brodowski

init: use do_mount() instead of ksys_mount()

2019-12-12T13:50:05+00:00

In prepare_namespace(), do_mount() can be used instead of ksys_mount()
as the first and third argument are const strings in the kernel, the
second and fourth argument are passed through anyway, and the fifth
argument is NULL.

In do_mount_root(), ksys_mount() is called with the first and third
argument being already kernelspace strings, which do not need to be
copied over from userspace to kernelspace (again). The second and
fourth arguments are passed through to do_mount() anyway. The fifth
argument, while already residing in kernelspace, needs to be put into
a page of its own. Then, do_mount() can be used instead of
ksys_mount().

Once this is done, there are no in-kernel users to ksys_mount() left,
which can therefore be removed.

Signed-off-by: Dominik Brodowski

initrd: use do_mount() instead of ksys_mount()

2019-12-12T13:50:03+00:00

All three calls to ksys_mount() in initrd-related kernel code can
be switched over to do_mount():
- the first and third arguments are const strings in the kernel,
  and do not need to be copied over from userspace;
- the fifth argument is NULL, and therefore no page needs to be,
  copied over from userspace;
- the second and fourth argument are passed through anyway.

Signed-off-by: Dominik Brodowski

devtmpfs: use do_mount() instead of ksys_mount()

2019-12-12T13:49:57+00:00

In devtmpfs, do_mount() can be called directly instead of complex wrapping
by ksys_mount():
- the first and third arguments are const strings in the kernel,
  and do not need to be copied over from userspace;
- the fifth argument is NULL, and therefore no page needs to be
  copied over from userspace;
- the second and fourth argument are passed through anyway.

Signed-off-by: Dominik Brodowski

init/Kconfig: fix indentation

2019-12-05T03:44:13+00:00

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
	$ sed -e 's/^        /	/' -i */Kconfig

Link: http://lkml.kernel.org/r/1574306670-30234-1-git-send-email-krzk@kernel.org
Signed-off-by: Krzysztof Kozlowski 
Cc: Jiri Kosina 
Cc: Masahiro Yamada 
Cc: Greg Kroah-Hartman 
Cc: David Hildenbrand 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'kbuild-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2019-12-03T01:35:04+00:00

Pull Kbuild updates from Masahiro Yamada:

 - remove unneeded asm headers from hexagon, ia64

 - add 'dir-pkg' target, which works like 'tar-pkg' but skips archiving

 - add 'helpnewconfig' target, which shows help for new CONFIG options

 - support 'make nsdeps' for external modules

 - make rebuilds faster by deleting $(wildcard $^) checks

 - remove compile tests for kernel-space headers

 - refactor modpost to simplify modversion handling

 - make single target builds faster

 - optimize and clean up scripts/kallsyms.c

 - refactor various Makefiles and scripts

* tag 'kbuild-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (59 commits)
  MAINTAINERS: update Kbuild/Kconfig maintainer's email address
  scripts/kallsyms: remove redundant initializers
  scripts/kallsyms: put check_symbol_range() calls close together
  scripts/kallsyms: make check_symbol_range() void function
  scripts/kallsyms: move ignored symbol types to is_ignored_symbol()
  scripts/kallsyms: move more patterns to the ignored_prefixes array
  scripts/kallsyms: skip ignored symbols very early
  scripts/kallsyms: add const qualifiers where possible
  scripts/kallsyms: make find_token() return (unsigned char *)
  scripts/kallsyms: replace prefix_underscores_count() with strspn()
  scripts/kallsyms: add sym_name() to mitigate cast ugliness
  scripts/kallsyms: remove unneeded length check for prefix matching
  scripts/kallsyms: remove redundant is_arm_mapping_symbol()
  scripts/kallsyms: set relative_base more effectively
  scripts/kallsyms: shrink table before sorting it
  scripts/kallsyms: fix definitely-lost memory leak
  scripts/kallsyms: remove unneeded #ifndef ARRAY_SIZE
  kbuild: make single target builds even faster
  modpost: respect the previous export when 'exported twice' is warned
  modpost: do not set ->preloaded for symbols from Module.symvers
  ...