Commit Graph

12 Commits

Author SHA1 Message Date
Mateusz Guzik
dc3c991598 Add char and short types to kcsan 2020-07-04 06:22:05 +00:00
Conrad Meyer
852c303b61 copystr(9): Move to deprecate (attempt #2)
This reapplies logical r360944 and r360946 (reverting r360955), with fixed
copystr() stand-in replacement macro.  Eventually the goal is to convert
consumers and kill the macro, but for a first step it helps if the macro is
correct.

Prior commit message:

Unlike the other copy*() functions, it does not serve to copy from one
address space to another or protect against potential faults.  It's just
an older incarnation of the now-more-common strlcpy().

Add a coccinelle script to tools/ which can be used to mechanically
convert existing instances where replacement with strlcpy is trivial.
In the two cases which matched, fuse_vfsops.c and union_vfsops.c, the
code was further refactored manually to simplify.

Replace the declaration of copystr() in systm.h with a small macro
wrapper around strlcpy (with correction from brooks@ -- thanks).

Remove N redundant MI implementations of copystr.  For MIPS, this
entailed inlining the assembler copystr into the only consumer,
copyinstr, and making the latter a leaf function.

Reviewed by:		jhb (earlier version)
Discussed with:		brooks (thanks!)
Differential Revision:	https://reviews.freebsd.org/D24672
2020-05-25 16:40:48 +00:00
Conrad Meyer
051fc58cb3 Revert r360944 and r360946 until reported issues can be resolved
Reported by:	cy
2020-05-12 04:34:26 +00:00
Conrad Meyer
580744621f copystr(9): Move to deprecate [2/2]
Unlike the other copy*() functions, it does not serve to copy from one
address space to another or protect against potential faults.  It's just
an older incarnation of the now-more-common strlcpy().

Add a coccinelle script to tools/ which can be used to mechanically
convert existing instances where replacement with strlcpy is trivial.
In the two cases which matched, fuse_vfsops.c and union_vfsops.c, the
code was further refactored manually to simplify.

Replace the declaration of copystr() in systm.h with a small macro
wrapper around strlcpy.

Remove N redundant MI implementations of copystr.  For MIPS, this
entailed inlining the assembler copystr into the only consumer,
copyinstr, and making the latter a leaf function.

Reviewed by:	jhb
Differential Revision:	https://reviews.freebsd.org/D24672
2020-05-11 22:57:21 +00:00
Conrad Meyer
ca0ec73c11 Expand generic subword atomic primitives
The goal of this change is to make the atomic_load_acq_{8,16},
atomic_testandset{,_acq}_long, and atomic_testandclear_long primitives
available in MI-namespace.

The second goal is to get this draft out of my local tree, as anything that
requires a full tinderbox is a big burden out of tree.  MD specifics can be
refined individually afterwards.

The generic implementations may not be ideal for your architecture; feel
free to implement better versions.  If no subword_atomic definitions are
needed, the include can be removed from your arch's machine/atomic.h.
Generic definitions are guarded by defined macros of the same name.  To
avoid picking up conflicting generic definitions, some macro defines are
added to various MD machine/atomic.h to register an existing implementation.

Include _atomic_subword.h in arm and arm64 machine/atomic.h.

For some odd reason, KCSAN only generates some versions of primitives.
Generate the _acq variants of atomic_load.*_8, atomic_load.*_16, and
atomic_testandset.*_long.  There are other questionably disabled primitives,
but I didn't run into them, so I left them alone.  KCSAN is only built for
amd64 in tinderbox for now.

Add atomic_subword implementations of atomic_load_acq_{8,16} implemented
using masking and atomic_load_acq_32.

Add generic atomic_subword implementations of atomic_testandset_long(),
atomic_testandclear_long(), and atomic_testandset_acq_long(), using
atomic_fcmpset_long() and atomic_fcmpset_acq_long().

On x86, add atomic_testandset_acq_long as an alias for
atomic_testandset_long.

Reviewed by:	kevans, rlibby (previous versions both)
Differential Revision:	https://reviews.freebsd.org/D22963
2020-03-25 23:12:43 +00:00
Mateusz Guzik
3ff65f71cb Remove duplicated empty lines from kern/*.c
No functional changes.
2020-01-30 20:05:05 +00:00
Mateusz Guzik
879e0604ee Add KERNEL_PANICKED macro for use in place of direct panicstr tests 2020-01-12 06:07:54 +00:00
Andrew Turner
a27ac4644a Disable KCSAN within a panic.
The kernel is single threaded at this point and the panic is more
important.

Sponsored by:	DARPA, AFRL
2019-11-21 13:59:01 +00:00
Andrew Turner
68cad68149 Add kcsan_md_unsupported from NetBSD.
It's used to ignore virtual addresses that may have a different physical
address depending on the CPU.

Sponsored by:	DARPA, AFRL
2019-11-21 13:22:23 +00:00
Andrew Turner
bba0065f0d Fix the bus_space functions with KCSAN on arm64.
Arm64 doesn't define the bus_space_set_multi_stream and
bus_space_set_region_stream functions. Don't try to define them there.

Sponsored by:	DARPA, AFRL
2019-11-21 13:12:58 +00:00
Andrew Turner
849aef496d Port the NetBSD KCSAN runtime to FreeBSD.
Update the NetBSD Kernel Concurrency Sanitizer (KCSAN) runtime to work in
the FreeBSD kernel. It is a useful tool for finding data races between
threads executing on different CPUs.

This can be enabled by enabling KCSAN in the kernel config, or by using the
GENERIC-KCSAN amd64 kernel. It works on amd64 and arm64, however the later
needs a compiler change to allow -fsanitize=thread that KCSAN uses.

Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D22315
2019-11-21 11:22:08 +00:00
Andrew Turner
0cb5357037 Import the NetBSD Kernel Concurrency Sanitizer (KCSAN) runtime.
KCSAN is a tool to find concurrent memory access that may race each other.
After a determined number of memory accesses a cell is created, this
describes the current access. It will then delay for a short period
to allow other CPUs a chance to race. If another CPU performs a memory
access to an overlapping region during this delay the race is reported.

This is a straight import of the NetBSD code, it will be adapted to
FreeBSD in a future commit.

Sponsored by:	DARPA, AFRL
2019-11-20 14:37:48 +00:00