| Message ID | 20211204032420.3158-1-hjl.tools@gmail.com |
|---|---|
| State | Committed |
| Commit | 4df1fa6ddc8925a75f3da644d5da3bb16eb33f02 |
| Headers | show |
| Series | x86-64: Use notl in EVEX strcmp [BZ #28646] | expand |
| Context | Check | Description |
|---|---|---|
| dj/TryBot-apply_patch | success | Patch applied to master at the time it was sent |
| dj/TryBot-32bit | success | Build for i686 |
On Fri, Dec 3, 2021 at 9:24 PM H.J. Lu <hjl.tools@gmail.com> wrote: > > From: Noah Goldstein <goldstein.w.n@gmail.com> > > Must use notl %edi here as lower bits are for CHAR comparisons > potentially out of range thus can be 0 without indicating mismatch. > This fixes BZ #28646. > > Co-Authored-By: H.J. Lu <hjl.tools@gmail.com> > --- > string/test-strcmp.c | 28 ++++++++++++++++++++++++++ > sysdeps/x86_64/multiarch/strcmp-evex.S | 14 +++++++------ > 2 files changed, 36 insertions(+), 6 deletions(-) > > diff --git a/string/test-strcmp.c b/string/test-strcmp.c > index 77ae73110f..42178a260b 100644 > --- a/string/test-strcmp.c > +++ b/string/test-strcmp.c > @@ -23,6 +23,7 @@ > # define TEST_NAME "strcmp" > #endif > #include "test-string.h" > +#include <support/test-driver.h> > > #ifdef WIDE > # include <wchar.h> > @@ -390,6 +391,32 @@ check2 (void) > } > } > > +static void > +check3 (void) > +{ > + size_t size = 0xd000 + 0x4000; > + CHAR *s1, *s2; > + CHAR *buffer1 = mmap (NULL, size, PROT_READ | PROT_WRITE, > + MAP_PRIVATE | MAP_ANON, -1, 0); > + CHAR *buffer2 = mmap (NULL, size, PROT_READ | PROT_WRITE, > + MAP_PRIVATE | MAP_ANON, -1, 0); > + if (buffer1 == MAP_FAILED || buffer1 == MAP_FAILED) > + error (EXIT_UNSUPPORTED, errno, "mmap failed"); > + > + s1 = (CHAR *) (buffer1 + 0x8f8 / sizeof (CHAR)); > + s2 = (CHAR *) (buffer2 + 0xcff3 / sizeof (CHAR)); > + > + STRCPY(s1, L("/export/redhat/rpms/BUILD/java-1.8.0-openjdk-1.8.0.312.b07-2.fc35.x86_64/openjdk/langtools/src/share/classes/com/sun/tools/doclets/internal/toolkit/util/PathDocFileFactory.java")); > + STRCPY(s2, L("/export/redhat/rpms/BUILD/java-1.8.0-openjdk-1.8.0.312.b07-2.fc35.x86_64/openjdk/langtools/src/share/classes/com/sun/tools/doclets/internal/toolkit/taglets/ThrowsTaglet.java")); > + > + int exp_result = SIMPLE_STRCMP (s1, s2); > + FOR_EACH_IMPL (impl, 0) > + check_result (impl, s1, s2, exp_result); > + > + munmap ((void *) buffer1, size); > + munmap ((void *) buffer2, size); > +} > + > int > test_main (void) > { > @@ -398,6 +425,7 @@ test_main (void) > test_init (); > check(); > check2 (); > + check3 (); > > printf ("%23s", ""); > FOR_EACH_IMPL (impl, 0) > diff --git a/sysdeps/x86_64/multiarch/strcmp-evex.S b/sysdeps/x86_64/multiarch/strcmp-evex.S > index 0bea318abd..b68e1f7a1e 100644 > --- a/sysdeps/x86_64/multiarch/strcmp-evex.S > +++ b/sysdeps/x86_64/multiarch/strcmp-evex.S > @@ -646,12 +646,13 @@ L(loop_cross_page): > in YMM3 and 32 bytes at VEC_SIZE(%rdx, %r10). */ > VPCMP $0, VEC_SIZE(%rdx, %r10), %YMM3, %k3{%k4} > kmovd %k3, %edi > + /* Must use notl %edi here as lower bits are for CHAR > + comparisons potentially out of range thus can be 0 without > + indicating mismatch. */ > + notl %edi > # ifdef USE_AS_WCSCMP > /* Don't use subl since it is the upper 8 bits of EDI below. */ > - notl %edi > andl $0xff, %edi > -# else > - incl %edi > # endif > > # ifdef USE_AS_WCSCMP > @@ -733,12 +734,13 @@ L(loop_cross_page_2_vec): > in YMM1 and 32 bytes at (VEC_SIZE * 3)(%rdx, %r10). */ > VPCMP $0, (VEC_SIZE * 3)(%rdx, %r10), %YMM1, %k3{%k4} > kmovd %k3, %edi > + /* Must use notl %edi here as lower bits are for CHAR > + comparisons potentially out of range thus can be 0 without > + indicating mismatch. */ > + notl %edi > # ifdef USE_AS_WCSCMP > /* Don't use subl since it is the upper 8 bits of EDI below. */ > - notl %edi > andl $0xff, %edi > -# else > - incl %edi > # endif > > # ifdef USE_AS_WCSCMP > -- > 2.33.1 > LGTM
On Dez 03 2021, H.J. Lu via Libc-alpha wrote: > diff --git a/sysdeps/x86_64/multiarch/strcmp-evex.S b/sysdeps/x86_64/multiarch/strcmp-evex.S > index 0bea318abd..b68e1f7a1e 100644 > --- a/sysdeps/x86_64/multiarch/strcmp-evex.S > +++ b/sysdeps/x86_64/multiarch/strcmp-evex.S > @@ -646,12 +646,13 @@ L(loop_cross_page): > in YMM3 and 32 bytes at VEC_SIZE(%rdx, %r10). */ > VPCMP $0, VEC_SIZE(%rdx, %r10), %YMM3, %k3{%k4} > kmovd %k3, %edi > + /* Must use notl %edi here as lower bits are for CHAR > + comparisons potentially out of range thus can be 0 without > + indicating mismatch. */ > + notl %edi Spacing off in the first line. Andreas.
On Fri, Dec 3, 2021 at 7:50 PM Noah Goldstein via Libc-alpha <libc-alpha@sourceware.org> wrote: > > On Fri, Dec 3, 2021 at 9:24 PM H.J. Lu <hjl.tools@gmail.com> wrote: > > > > From: Noah Goldstein <goldstein.w.n@gmail.com> > > > > Must use notl %edi here as lower bits are for CHAR comparisons > > potentially out of range thus can be 0 without indicating mismatch. > > This fixes BZ #28646. > > > > Co-Authored-By: H.J. Lu <hjl.tools@gmail.com> > > --- > > string/test-strcmp.c | 28 ++++++++++++++++++++++++++ > > sysdeps/x86_64/multiarch/strcmp-evex.S | 14 +++++++------ > > 2 files changed, 36 insertions(+), 6 deletions(-) > > > > diff --git a/string/test-strcmp.c b/string/test-strcmp.c > > index 77ae73110f..42178a260b 100644 > > --- a/string/test-strcmp.c > > +++ b/string/test-strcmp.c > > @@ -23,6 +23,7 @@ > > # define TEST_NAME "strcmp" > > #endif > > #include "test-string.h" > > +#include <support/test-driver.h> > > > > #ifdef WIDE > > # include <wchar.h> > > @@ -390,6 +391,32 @@ check2 (void) > > } > > } > > > > +static void > > +check3 (void) > > +{ > > + size_t size = 0xd000 + 0x4000; > > + CHAR *s1, *s2; > > + CHAR *buffer1 = mmap (NULL, size, PROT_READ | PROT_WRITE, > > + MAP_PRIVATE | MAP_ANON, -1, 0); > > + CHAR *buffer2 = mmap (NULL, size, PROT_READ | PROT_WRITE, > > + MAP_PRIVATE | MAP_ANON, -1, 0); > > + if (buffer1 == MAP_FAILED || buffer1 == MAP_FAILED) > > + error (EXIT_UNSUPPORTED, errno, "mmap failed"); > > + > > + s1 = (CHAR *) (buffer1 + 0x8f8 / sizeof (CHAR)); > > + s2 = (CHAR *) (buffer2 + 0xcff3 / sizeof (CHAR)); > > + > > + STRCPY(s1, L("/export/redhat/rpms/BUILD/java-1.8.0-openjdk-1.8.0.312.b07-2.fc35.x86_64/openjdk/langtools/src/share/classes/com/sun/tools/doclets/internal/toolkit/util/PathDocFileFactory.java")); > > + STRCPY(s2, L("/export/redhat/rpms/BUILD/java-1.8.0-openjdk-1.8.0.312.b07-2.fc35.x86_64/openjdk/langtools/src/share/classes/com/sun/tools/doclets/internal/toolkit/taglets/ThrowsTaglet.java")); > > + > > + int exp_result = SIMPLE_STRCMP (s1, s2); > > + FOR_EACH_IMPL (impl, 0) > > + check_result (impl, s1, s2, exp_result); > > + > > + munmap ((void *) buffer1, size); > > + munmap ((void *) buffer2, size); > > +} > > + > > int > > test_main (void) > > { > > @@ -398,6 +425,7 @@ test_main (void) > > test_init (); > > check(); > > check2 (); > > + check3 (); > > > > printf ("%23s", ""); > > FOR_EACH_IMPL (impl, 0) > > diff --git a/sysdeps/x86_64/multiarch/strcmp-evex.S b/sysdeps/x86_64/multiarch/strcmp-evex.S > > index 0bea318abd..b68e1f7a1e 100644 > > --- a/sysdeps/x86_64/multiarch/strcmp-evex.S > > +++ b/sysdeps/x86_64/multiarch/strcmp-evex.S > > @@ -646,12 +646,13 @@ L(loop_cross_page): > > in YMM3 and 32 bytes at VEC_SIZE(%rdx, %r10). */ > > VPCMP $0, VEC_SIZE(%rdx, %r10), %YMM3, %k3{%k4} > > kmovd %k3, %edi > > + /* Must use notl %edi here as lower bits are for CHAR > > + comparisons potentially out of range thus can be 0 without > > + indicating mismatch. */ > > + notl %edi > > # ifdef USE_AS_WCSCMP > > /* Don't use subl since it is the upper 8 bits of EDI below. */ > > - notl %edi > > andl $0xff, %edi > > -# else > > - incl %edi > > # endif > > > > # ifdef USE_AS_WCSCMP > > @@ -733,12 +734,13 @@ L(loop_cross_page_2_vec): > > in YMM1 and 32 bytes at (VEC_SIZE * 3)(%rdx, %r10). */ > > VPCMP $0, (VEC_SIZE * 3)(%rdx, %r10), %YMM1, %k3{%k4} > > kmovd %k3, %edi > > + /* Must use notl %edi here as lower bits are for CHAR > > + comparisons potentially out of range thus can be 0 without > > + indicating mismatch. */ > > + notl %edi > > # ifdef USE_AS_WCSCMP > > /* Don't use subl since it is the upper 8 bits of EDI below. */ > > - notl %edi > > andl $0xff, %edi > > -# else > > - incl %edi > > # endif > > > > # ifdef USE_AS_WCSCMP > > -- > > 2.33.1 > > > > LGTM I would like to backport this patch to release branches. Any comments or objections? --Sunil
diff --git a/string/test-strcmp.c b/string/test-strcmp.c index 77ae73110f..42178a260b 100644 --- a/string/test-strcmp.c +++ b/string/test-strcmp.c @@ -23,6 +23,7 @@ # define TEST_NAME "strcmp" #endif #include "test-string.h" +#include <support/test-driver.h> #ifdef WIDE # include <wchar.h> @@ -390,6 +391,32 @@ check2 (void) } } +static void +check3 (void) +{ + size_t size = 0xd000 + 0x4000; + CHAR *s1, *s2; + CHAR *buffer1 = mmap (NULL, size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON, -1, 0); + CHAR *buffer2 = mmap (NULL, size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON, -1, 0); + if (buffer1 == MAP_FAILED || buffer1 == MAP_FAILED) + error (EXIT_UNSUPPORTED, errno, "mmap failed"); + + s1 = (CHAR *) (buffer1 + 0x8f8 / sizeof (CHAR)); + s2 = (CHAR *) (buffer2 + 0xcff3 / sizeof (CHAR)); + + STRCPY(s1, L("/export/redhat/rpms/BUILD/java-1.8.0-openjdk-1.8.0.312.b07-2.fc35.x86_64/openjdk/langtools/src/share/classes/com/sun/tools/doclets/internal/toolkit/util/PathDocFileFactory.java")); + STRCPY(s2, L("/export/redhat/rpms/BUILD/java-1.8.0-openjdk-1.8.0.312.b07-2.fc35.x86_64/openjdk/langtools/src/share/classes/com/sun/tools/doclets/internal/toolkit/taglets/ThrowsTaglet.java")); + + int exp_result = SIMPLE_STRCMP (s1, s2); + FOR_EACH_IMPL (impl, 0) + check_result (impl, s1, s2, exp_result); + + munmap ((void *) buffer1, size); + munmap ((void *) buffer2, size); +} + int test_main (void) { @@ -398,6 +425,7 @@ test_main (void) test_init (); check(); check2 (); + check3 (); printf ("%23s", ""); FOR_EACH_IMPL (impl, 0) diff --git a/sysdeps/x86_64/multiarch/strcmp-evex.S b/sysdeps/x86_64/multiarch/strcmp-evex.S index 0bea318abd..b68e1f7a1e 100644 --- a/sysdeps/x86_64/multiarch/strcmp-evex.S +++ b/sysdeps/x86_64/multiarch/strcmp-evex.S @@ -646,12 +646,13 @@ L(loop_cross_page): in YMM3 and 32 bytes at VEC_SIZE(%rdx, %r10). */ VPCMP $0, VEC_SIZE(%rdx, %r10), %YMM3, %k3{%k4} kmovd %k3, %edi + /* Must use notl %edi here as lower bits are for CHAR + comparisons potentially out of range thus can be 0 without + indicating mismatch. */ + notl %edi # ifdef USE_AS_WCSCMP /* Don't use subl since it is the upper 8 bits of EDI below. */ - notl %edi andl $0xff, %edi -# else - incl %edi # endif # ifdef USE_AS_WCSCMP @@ -733,12 +734,13 @@ L(loop_cross_page_2_vec): in YMM1 and 32 bytes at (VEC_SIZE * 3)(%rdx, %r10). */ VPCMP $0, (VEC_SIZE * 3)(%rdx, %r10), %YMM1, %k3{%k4} kmovd %k3, %edi + /* Must use notl %edi here as lower bits are for CHAR + comparisons potentially out of range thus can be 0 without + indicating mismatch. */ + notl %edi # ifdef USE_AS_WCSCMP /* Don't use subl since it is the upper 8 bits of EDI below. */ - notl %edi andl $0xff, %edi -# else - incl %edi # endif # ifdef USE_AS_WCSCMP
From: Noah Goldstein <goldstein.w.n@gmail.com> Must use notl %edi here as lower bits are for CHAR comparisons potentially out of range thus can be 0 without indicating mismatch. This fixes BZ #28646. Co-Authored-By: H.J. Lu <hjl.tools@gmail.com> --- string/test-strcmp.c | 28 ++++++++++++++++++++++++++ sysdeps/x86_64/multiarch/strcmp-evex.S | 14 +++++++------ 2 files changed, 36 insertions(+), 6 deletions(-)