diff options
author | Dan Williams <dan.j.williams@intel.com> | 2020-10-05 20:40:16 -0700 |
---|---|---|
committer | Borislav Petkov <bp@suse.de> | 2020-10-06 11:18:04 +0200 |
commit | ec6347bb43395cb92126788a1a5b25302543f815 (patch) | |
tree | 98a65bc27c57de7d21fdf657e0e94a95bb50935f /tools/testing | |
parent | ed9705e4ad1c19ae51ed0cb4c112f9eb6dfc69fc (diff) | |
download | linux-ec6347bb43395cb92126788a1a5b25302543f815.tar.bz2 |
x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()
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:
On Fri, May 1, 2020 at 11:28 AM Linus Torvalds <torvalds@linux-foundation.org> wrote:
>
> On Thu, Apr 30, 2020 at 6:21 PM Dan Williams <dan.j.williams@intel.com> wrote:
> >
> > However now I see that copy_user_generic() works for the wrong reason.
> > It works because the exception on the source address due to poison
> > looks no different than a write fault on the user address to the
> > caller, it's still just a short copy. So it makes copy_to_user() work
> > for the wrong reason relative to the name.
>
> Right.
>
> And it won't work that way on other architectures. On x86, we have a
> generic function that can take faults on either side, and we use it
> for both cases (and for the "in_user" case too), but that's an
> artifact of the architecture oddity.
>
> In fact, it's probably wrong even on x86 - because it can hide bugs -
> but writing those things is painful enough that everybody prefers
> having just one function.
Replace a single top-level memcpy_mcsafe() with either
copy_mc_to_user(), or copy_mc_to_kernel().
Introduce an x86 copy_mc_fragile() name as the rename for the
low-level x86 implementation formerly named memcpy_mcsafe(). It is used
as the slow / careful backend that is supplanted by a fast
copy_mc_generic() in a follow-on patch.
One side-effect of this reorganization is that separating copy_mc_64.S
to its own file means that perf no longer needs to track dependencies
for its memcpy_64.S benchmarks.
[ bp: Massage a bit. ]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: <stable@vger.kernel.org>
Link: http://lore.kernel.org/r/CAHk-=wjSqtXAqfUJxFtWNwmguFASTgB0dz1dT3V-78Quiezqbg@mail.gmail.com
Link: https://lkml.kernel.org/r/160195561680.2163339.11574962055305783722.stgit@dwillia2-desk3.amr.corp.intel.com
Diffstat (limited to 'tools/testing')
5 files changed, 30 insertions, 29 deletions
diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c index a1a5dc645b40..2ac0fff6dad8 100644 --- a/tools/testing/nvdimm/test/nfit.c +++ b/tools/testing/nvdimm/test/nfit.c @@ -23,7 +23,8 @@ #include "nfit_test.h" #include "../watermark.h" -#include <asm/mcsafe_test.h> +#include <asm/copy_mc_test.h> +#include <asm/mce.h> /* * Generate an NFIT table to describe the following topology: @@ -3283,7 +3284,7 @@ static struct platform_driver nfit_test_driver = { .id_table = nfit_test_id, }; -static char mcsafe_buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); +static char copy_mc_buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); enum INJECT { INJECT_NONE, @@ -3291,7 +3292,7 @@ enum INJECT { INJECT_DST, }; -static void mcsafe_test_init(char *dst, char *src, size_t size) +static void copy_mc_test_init(char *dst, char *src, size_t size) { size_t i; @@ -3300,7 +3301,7 @@ static void mcsafe_test_init(char *dst, char *src, size_t size) src[i] = (char) i; } -static bool mcsafe_test_validate(unsigned char *dst, unsigned char *src, +static bool copy_mc_test_validate(unsigned char *dst, unsigned char *src, size_t size, unsigned long rem) { size_t i; @@ -3321,12 +3322,12 @@ static bool mcsafe_test_validate(unsigned char *dst, unsigned char *src, return true; } -void mcsafe_test(void) +void copy_mc_test(void) { char *inject_desc[] = { "none", "source", "destination" }; enum INJECT inj; - if (IS_ENABLED(CONFIG_MCSAFE_TEST)) { + if (IS_ENABLED(CONFIG_COPY_MC_TEST)) { pr_info("%s: run...\n", __func__); } else { pr_info("%s: disabled, skip.\n", __func__); @@ -3344,31 +3345,31 @@ void mcsafe_test(void) switch (inj) { case INJECT_NONE: - mcsafe_inject_src(NULL); - mcsafe_inject_dst(NULL); - dst = &mcsafe_buf[2048]; - src = &mcsafe_buf[1024 - i]; + copy_mc_inject_src(NULL); + copy_mc_inject_dst(NULL); + dst = ©_mc_buf[2048]; + src = ©_mc_buf[1024 - i]; expect = 0; break; case INJECT_SRC: - mcsafe_inject_src(&mcsafe_buf[1024]); - mcsafe_inject_dst(NULL); - dst = &mcsafe_buf[2048]; - src = &mcsafe_buf[1024 - i]; + copy_mc_inject_src(©_mc_buf[1024]); + copy_mc_inject_dst(NULL); + dst = ©_mc_buf[2048]; + src = ©_mc_buf[1024 - i]; expect = 512 - i; break; case INJECT_DST: - mcsafe_inject_src(NULL); - mcsafe_inject_dst(&mcsafe_buf[2048]); - dst = &mcsafe_buf[2048 - i]; - src = &mcsafe_buf[1024]; + copy_mc_inject_src(NULL); + copy_mc_inject_dst(©_mc_buf[2048]); + dst = ©_mc_buf[2048 - i]; + src = ©_mc_buf[1024]; expect = 512 - i; break; } - mcsafe_test_init(dst, src, 512); - rem = __memcpy_mcsafe(dst, src, 512); - valid = mcsafe_test_validate(dst, src, 512, expect); + copy_mc_test_init(dst, src, 512); + rem = copy_mc_fragile(dst, src, 512); + valid = copy_mc_test_validate(dst, src, 512, expect); if (rem == expect && valid) continue; pr_info("%s: copy(%#lx, %#lx, %d) off: %d rem: %ld %s expect: %ld\n", @@ -3380,8 +3381,8 @@ void mcsafe_test(void) } } - mcsafe_inject_src(NULL); - mcsafe_inject_dst(NULL); + copy_mc_inject_src(NULL); + copy_mc_inject_dst(NULL); } static __init int nfit_test_init(void) @@ -3392,7 +3393,7 @@ static __init int nfit_test_init(void) libnvdimm_test(); acpi_nfit_test(); device_dax_test(); - mcsafe_test(); + copy_mc_test(); dax_pmem_test(); dax_pmem_core_test(); #ifdef CONFIG_DEV_DAX_PMEM_COMPAT diff --git a/tools/testing/selftests/powerpc/copyloops/.gitignore b/tools/testing/selftests/powerpc/copyloops/.gitignore index ddaf140b8255..994b11af765c 100644 --- a/tools/testing/selftests/powerpc/copyloops/.gitignore +++ b/tools/testing/selftests/powerpc/copyloops/.gitignore @@ -12,4 +12,4 @@ memcpy_p7_t1 copyuser_64_exc_t0 copyuser_64_exc_t1 copyuser_64_exc_t2 -memcpy_mcsafe_64 +copy_mc_64 diff --git a/tools/testing/selftests/powerpc/copyloops/Makefile b/tools/testing/selftests/powerpc/copyloops/Makefile index 0917983a1c78..3095b1f1c02b 100644 --- a/tools/testing/selftests/powerpc/copyloops/Makefile +++ b/tools/testing/selftests/powerpc/copyloops/Makefile @@ -12,7 +12,7 @@ ASFLAGS = $(CFLAGS) -Wa,-mpower4 TEST_GEN_PROGS := copyuser_64_t0 copyuser_64_t1 copyuser_64_t2 \ copyuser_p7_t0 copyuser_p7_t1 \ memcpy_64_t0 memcpy_64_t1 memcpy_64_t2 \ - memcpy_p7_t0 memcpy_p7_t1 memcpy_mcsafe_64 \ + memcpy_p7_t0 memcpy_p7_t1 copy_mc_64 \ copyuser_64_exc_t0 copyuser_64_exc_t1 copyuser_64_exc_t2 EXTRA_SOURCES := validate.c ../harness.c stubs.S @@ -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_64: copy_mc_64.S $(EXTRA_SOURCES) $(CC) $(CPPFLAGS) $(CFLAGS) \ - -D COPY_LOOP=test_memcpy_mcsafe \ + -D COPY_LOOP=test_copy_mc_generic \ -o $@ $^ $(OUTPUT)/copyuser_64_exc_t%: copyuser_64.S exc_validate.c ../harness.c \ diff --git a/tools/testing/selftests/powerpc/copyloops/copy_mc_64.S b/tools/testing/selftests/powerpc/copyloops/copy_mc_64.S new file mode 120000 index 000000000000..dcbe06d500fb --- /dev/null +++ b/tools/testing/selftests/powerpc/copyloops/copy_mc_64.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 |