7:53 p.m.
Hi Dan,
Just a couple of minor things ...
Dan Williams <dan.j.williams(a)intel.com> writes:
In reaction to a proposal to introduce a memcpy_mcsafe_fast()
implementation Linus points out that memcpy_mcsafe() is poorly named
relative to communicating the scope of the interface. Specifically what
addresses are valid to pass as source, destination, and what faults /
exceptions are handled. Of particular concern is that even though x86
might be able to handle the semantics of copy_mc_to_user() with its
common copy_user_generic() implementation other archs likely need / want
an explicit path for this case:
...
diff --git a/arch/powerpc/include/asm/uaccess.h
b/arch/powerpc/include/asm/uaccess.h
index 0969285996cb..dcbbcbf3552c 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -348,6 +348,32 @@ do { \
extern unsigned long __copy_tofrom_user(void __user *to,
const void __user *from, unsigned long size);
+#ifdef CONFIG_ARCH_HAS_COPY_MC
+extern unsigned long __must_check
We try not to add extern in headers anymore.
+copy_mc_generic(void *to, const void *from, unsigned long size);
+
+static inline unsigned long __must_check
+copy_mc_to_kernel(void *to, const void *from, unsigned long size)
+{
+ return copy_mc_generic(to, from, size);
+}
+#define copy_mc_to_kernel copy_mc_to_kernel
+
+static inline unsigned long __must_check
+copy_mc_to_user(void __user *to, const void *from, unsigned long n)
+{
+ if (likely(check_copy_size(from, n, true))) {
+ if (access_ok(to, n)) {
+ allow_write_to_user(to, n);
+ n = copy_mc_generic((void *)to, from, n);
+ prevent_write_to_user(to, n);
+ }
+ }
+
+ return n;
+}
+#endif
Otherwise that looks fine.
...
diff --git a/tools/testing/selftests/powerpc/copyloops/Makefile
b/tools/testing/selftests/powerpc/copyloops/Makefile
index 0917983a1c78..959817e7567c 100644
--- a/tools/testing/selftests/powerpc/copyloops/Makefile
+++ b/tools/testing/selftests/powerpc/copyloops/Makefile
@@ -45,9 +45,9 @@ $(OUTPUT)/memcpy_p7_t%: memcpy_power7.S $(EXTRA_SOURCES)
-D SELFTEST_CASE=$(subst memcpy_p7_t,,$(notdir $@)) \
-o $@ $^
-$(OUTPUT)/memcpy_mcsafe_64: memcpy_mcsafe_64.S $(EXTRA_SOURCES)
+$(OUTPUT)/copy_mc: copy_mc.S $(EXTRA_SOURCES)
$(CC) $(CPPFLAGS) $(CFLAGS) \
- -D COPY_LOOP=test_memcpy_mcsafe \
+ -D COPY_LOOP=test_copy_mc \
This needs a fixup:
diff --git a/tools/testing/selftests/powerpc/copyloops/Makefile
b/tools/testing/selftests/powerpc/copyloops/Makefile
index 959817e7567c..b4eb5c4c6858 100644
--- a/tools/testing/selftests/powerpc/copyloops/Makefile
+++ b/tools/testing/selftests/powerpc/copyloops/Makefile
@@ -47,7 +47,7 @@ $(OUTPUT)/memcpy_p7_t%: memcpy_power7.S $(EXTRA_SOURCES)
$(OUTPUT)/copy_mc: copy_mc.S $(EXTRA_SOURCES)
$(CC) $(CPPFLAGS) $(CFLAGS) \
- -D COPY_LOOP=test_copy_mc \
+ -D COPY_LOOP=test_copy_mc_generic \
-o $@ $^
$(OUTPUT)/copyuser_64_exc_t%: copyuser_64.S exc_validate.c ../harness.c \
-o $@ $^
$(OUTPUT)/copyuser_64_exc_t%: copyuser_64.S exc_validate.c ../harness.c \
diff --git a/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S
b/tools/testing/selftests/powerpc/copyloops/copy_mc.S
similarity index 100%
rename from tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S
rename to tools/testing/selftests/powerpc/copyloops/copy_mc.S
This file is a symlink to the file in arch/powerpc/lib, so the name of
the link needs updating, as well as the target.
Also is there a reason you dropped the "_64"? It would make most sense
to keep it I think, as then the file in selftests and the file in arch/
have the same name.
If you want to keep the copy_mc.S name it needs the diff below. Though
as I said I think it would be better to use copy_mc_64.S.
cheers
diff --git a/tools/testing/selftests/powerpc/copyloops/copy_mc.S
b/tools/testing/selftests/powerpc/copyloops/copy_mc.S
new file mode 120000
index 000000000000..dcbe06d500fb
--- /dev/null
+++ b/tools/testing/selftests/powerpc/copyloops/copy_mc.S
@@ -0,0 +1 @@
+../../../../../arch/powerpc/lib/copy_mc_64.S
\ No newline at end of file
diff --git a/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S
b/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S
deleted file mode 120000
index f0feef3062f6..000000000000
--- a/tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S
+++ /dev/null
@@ -1 +0,0 @@
-../../../../../arch/powerpc/lib/memcpy_mcsafe_64.S
\ No newline at end of file
--
2.25.1