linux-stable.git/drivers/tty/vt/selection.c, branch linux-5.10.y

vc: propagate "viewed as bool" from screenpos up

2020-08-18T11:45:20+00:00

viewed is used as a flag, i.e. bool. So treat is as such in most of the
places. vcs_vc is handled in the next patch.

Note: the last parameter of invert_screen was misnamed in the
declaration since 1.1.92.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20200818085706.12163-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty/vt: Do not warn when huge selection requested

2020-07-01T13:29:35+00:00

The tty TIOCL_SETSEL ioctl allocates a memory buffer big enough for text
selection area. The maximum allowed console size is
VC_RESIZE_MAXCOL * VC_RESIZE_MAXROW == 32767*32767 == ~1GB and typical
MAX_ORDER is set to allow allocations lot less than than (circa 16MB).

So it is quite possible to trigger huge allocation (and syzkaller just
did that) which is going to fail (which is fine) with a backtrace in
mm/page_alloc.c at WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN)) and
this may trigger panic (if panic_on_warn is enabled) and
leak kernel addresses to dmesg.

This passes __GFP_NOWARN to kmalloc_array to avoid unnecessary user-
triggered WARN_ON. Note that the error is not ignored and
the warning is still printed.

Signed-off-by: Alexey Kardashevskiy 
Link: https://lore.kernel.org/r/20200617070444.116704-1-aik@ozlabs.ru
Signed-off-by: Greg Kroah-Hartman

vt: extract selection chars storing from vc_do_selection

2020-04-16T14:14:15+00:00

Let's put it to a separate function, named vc_selection_store_chars.
Again, this makes vc_do_selection a bit shorter and more readable.
Having 4 local variables instead of 12 (5.6-rc1) looks much better now.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20200415093608.10348-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

vt: selection, split __set_selection_kernel

2020-04-16T14:14:15+00:00

Handle these actions:
* poking console
* TIOCL_SELCLEAR
* TIOCL_SELMOUSEREPORT
* start/end precomputation
* clear_selection if the console changed
in a separate function, thus making __set_selection_kernel way shorter
and more readable. The function still needs dissection, but we are
approaching.

This includes introduction of vc_selection and renaming
__set_selection_kernel to vc_do_selection.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20200415093608.10348-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

vt: selection, use rounddown() for start/endline computation

2020-03-16T07:41:17+00:00

We have a helper called rounddown for these modulo computations. So use
it.

No functional change intended and "objdump -d" proves that.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20200316065911.11024-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

vt: selection, fix double lock introduced by a merge

2020-03-16T07:39:47+00:00

The merge commit cb05c6c82fb0 (Merge 5.6-rc5 into tty-next) introduced a
double lock to set_selection_kernel. vc_sel.lock is locked both in
set_selection_kernel and its callee __set_selection_kernel now.

Remove the latter.

Signed-off-by: Jiri Slaby 
Cc: Stephen Rothwell 
Link: https://lore.kernel.org/r/20200316064544.4799-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

Merge 5.6-rc5 into tty-next

2020-03-10T09:02:49+00:00

We need the vt fixes in here and it resolves a merge issue with
drivers/tty/vt/selection.c

Reported-by: Stephen Rothwell 
Signed-off-by: Greg Kroah-Hartman

vt: selection, indent switch-case properly

2020-03-06T07:35:40+00:00

Shift the cases one level left as this is how we are supposed to write
the switch-case code according to the CodingStyle.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20200219073951.16151-9-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

vt: selection, remove redeclaration of poke_blanked_console

2020-03-06T07:35:40+00:00

It is declared in vt_kern.h, so no need to declare it in selection.c
which includes the header.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20200219073951.16151-8-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

vt: selection, create struct from console selection globals

2020-03-06T07:35:39+00:00

Move all the selection global variables to a structure vc_selection,
instantiated as vc_sel. This helps to group all the variables together
and see what should be protected by the embedded lock too.

It might be used later also for per-console selection support.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20200219073951.16151-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman