Commit Graph

5 Commits

Author SHA1 Message Date
Daniel Leung fc182430c0 kernel: userspace: reserve stack space to store local data
This enables reserving little space on the top of stack to store
data local to thread when CONFIG_USERSPACE. The first customer
of this is errno.

Note that ARC, due to how it lays out the user stack and
privilege stack, sets the pointer itself rather than
relying on the common way.

Fixes: #9067

Signed-off-by: Daniel Leung <daniel.leung@intel.com>
2018-08-17 09:40:52 -07:00
Andrew Boie 7f4d006959 kernel: fix errno access for user mode
The errno "variable" is required to be thread-specific.
It gets defined to a macro which dereferences a pointer
returned by a kernel function.

In user mode, we cannot simply read/write the thread struct.
We do not have thread-local storage mechanism, so for now
use the lowest address of the thread stack to store this
value, since this is guaranteed to be read/writable by
a user thread.

The downside of this approach is potential stack corruption
if the stack pointer goes down this far but does not exceed
the location, since a fault won't be generated in this case.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2018-07-19 16:44:59 -07:00
Paul Sokolovsky 8cc6f6ddd6 kernel: errno: Use per-thread accessor function compatible with Newlib
Newlib names this function __errno(), so if we want Zephyr to work
with Newlib seamlessly, it's better to just follow Newlib's naming
convention for Zephyr's own minimal libc.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
2017-05-10 20:54:56 -04:00
David B. Kinder ac74d8b652 license: Replace Apache boilerplate with SPDX tag
Replace the existing Apache 2.0 boilerplate header with an SPDX tag
throughout the zephyr code tree. This patch was generated via a
script run over the master branch.

Also updated doc/porting/application.rst that had a dependency on
line numbers in a literal include.

Manually updated subsys/logging/sys_log.c that had a malformed
header in the original file.  Also cleanup several cases that already
had a SPDX tag and we either got a duplicate or missed updating.

Jira: ZEP-1457

Change-Id: I6131a1d4ee0e58f5b938300c2d2fc77d2e69572c
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2017-01-19 03:50:58 +00:00
Anas Nashif d687a95611 kernel: move kernel code to kernel/ directly
Also remove mentions of unified kernel in various places in the kernel,
samples and documentation.

Change-Id: Ice43bc73badbe7e14bae40fd6f2a302f6528a77d
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2016-12-19 14:59:35 -05:00