Thread (15 messages) flat view 15 messages, 4 authors, 2023-02-09

Re: [PATCH v4 7/7] powerpc: kcsan: Add KCSAN Support

From: Marco Elver <elver@google.com>
Date: 2023-02-08 10:11:50

On Wed, 8 Feb 2023 at 04:23, Rohan McLure [off-list ref] wrote:
Enable HAVE_ARCH_KCSAN on all powerpc platforms, permitting use of the
kernel concurrency sanitiser through the CONFIG_KCSAN_* kconfig options.
KCSAN requires compiler builtins __atomic_* 64-bit values, and so only
report support on PPC64.
I thought the stubs solve that?

In general the whole builtin atomic support is only there to support
some odd corner cases today (Clang GCOV generates builtin atomic ops,
occasionally some driver sneaks in a builtin atomic although it's
technically strongly discouraged, and probably Rust stuff in future).
So I'd like to keep them, although they shouldn't cause issues.
See documentation in Documentation/dev-tools/kcsan.rst for more
information.
Do the tests pass?
quoted hunk ↗ jump to hunk
Signed-off-by: Rohan McLure <redacted>
---
v3: Restrict support to 64-bit, as TSAN expects 64-bit __atomic_* compiler
built-ins.
---
 arch/powerpc/Kconfig | 1 +
 1 file changed, 1 insertion(+)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index b8c4ac56bddc..55bc2d724c73 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -198,6 +198,7 @@ config PPC
        select HAVE_ARCH_KASAN                  if PPC_RADIX_MMU
        select HAVE_ARCH_KASAN                  if PPC_BOOK3E_64
        select HAVE_ARCH_KASAN_VMALLOC          if HAVE_ARCH_KASAN
+       select HAVE_ARCH_KCSAN            if PPC64
        select HAVE_ARCH_KFENCE                 if ARCH_SUPPORTS_DEBUG_PAGEALLOC
        select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
        select HAVE_ARCH_KGDB
--
2.37.2
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help