[PATCH] x86_64: Build modf for libc and libm (BZ 33165)

Adhemerval Zanella adhemerval.zanella@linaro.org
Thu Jul 17 19:26:31 GMT 2025 

The routines that are shared between libc and libm should use different
rules to avoid using the same MODULE_NAME, to avoid potential issues
like BZ#33165 where __stack_chk_fail not being routed to the internal
symbol.

Checked with a build for x86_64-linux-gnu, x86_64-linux-gnu-v2,
x86_64-linux-gnu-v3, and x86_64-linux-gnu-v4 and -fstack-protector=all.
---
 sysdeps/x86_64/fpu/multiarch/Makefile         | 39 +++++++------------
 sysdeps/x86_64/fpu/multiarch/s_modf-avx.c     |  6 ++-
 sysdeps/x86_64/fpu/multiarch/s_modf-sse4_1.c  |  5 +--
 sysdeps/x86_64/fpu/multiarch/s_modf.c         |  2 +
 sysdeps/x86_64/fpu/multiarch/s_modff-avx.c    |  6 ++-
 sysdeps/x86_64/fpu/multiarch/s_modff-sse4_1.c |  4 +-
 sysdeps/x86_64/fpu/multiarch/s_modff.c        |  2 +
 7 files changed, 33 insertions(+), 31 deletions(-)

diff --git a/sysdeps/x86_64/fpu/multiarch/Makefile b/sysdeps/x86_64/fpu/multiarch/Makefile
index 81a870d3b1..289d3f6e0d 100644
--- a/sysdeps/x86_64/fpu/multiarch/Makefile
+++ b/sysdeps/x86_64/fpu/multiarch/Makefile
@@ -27,18 +27,17 @@ CFLAGS-s_cosf-fma.c = -mfma -mavx2
 CFLAGS-s_sincosf-fma.c = -mfma -mavx2
 
 # Check if ISA level is 3 or above.
-ifneq (,$(filter $(have-x86-isa-level),$(x86-isa-level-3-or-above)))
-sysdep_routines += \
+sysdep_calls += \
   s_modf-avx \
   s_modff-avx \
-# sysdep_routines
+# sysdep_calls
+ifneq (,$(filter $(have-x86-isa-level),$(x86-isa-level-3-or-above)))
+sysdep_routines += $(sysdep_calls)
 libm-sysdep_routines += \
   s_ceil-avx \
   s_ceilf-avx \
   s_floor-avx \
   s_floorf-avx \
-  s_modf-avx \
-  s_modff-avx \
   s_nearbyint-avx \
   s_nearbyintf-avx \
   s_rint-avx \
@@ -62,10 +61,10 @@ libm-sysdep_routines += \
   s_tan-fma4 \
 # libm-sysdep_routines
 endif
-sysdep_routines += \
+sysdep_calls += \
   s_modf-sse4_1 \
   s_modff-sse4_1 \
-# sysdep_routines
+# sysdep_calls
 libm-sysdep_routines += \
   e_asin-fma \
   e_atan2-avx \
@@ -95,8 +94,6 @@ libm-sysdep_routines += \
   s_floor-sse4_1 \
   s_floorf-sse4_1 \
   s_log1p-fma \
-  s_modf-sse4_1 \
-  s_modff-sse4_1 \
   s_nearbyint-sse4_1 \
   s_nearbyintf-sse4_1 \
   s_rint-sse4_1 \
@@ -118,17 +115,15 @@ libm-sysdep_routines += \
   s_truncf-sse4_1 \
 # libm-sysdep_routines
 ifeq ($(have-x86-isa-level),baseline)
-sysdep_routines += \
+sysdep_calls += \
   s_modf-c \
   s_modff-c \
-# sysdep-routines
+# sysdep-calls
 libm-sysdep_routines += \
   s_ceil-c \
   s_ceilf-c \
   s_floor-c \
   s_floorf-c \
-  s_modf-c \
-  s_modff-c \
   s_nearbyint-c \
   s_nearbyintf-c \
   s_rint-c \
@@ -139,6 +134,9 @@ libm-sysdep_routines += \
   s_truncf-c \
 # libm-sysdep_routines
 endif
+
+sysdep_routines += $(sysdep_calls)
+libm-sysdep_routines += $(sysdep_calls:s_%=m_%)
 endif
 
 CFLAGS-e_asin-fma4.c = -mfma4
@@ -159,18 +157,11 @@ CFLAGS-s_sin-avx.c = -msse2avx -DSSE2AVX
 CFLAGS-s_tan-avx.c = -msse2avx -DSSE2AVX
 CFLAGS-s_sincos-avx.c = -msse2avx -DSSE2AVX
 
-CFLAGS-s_modf-c.c = $(no-stack-protector)
-CFLAGS-s_modff-c.c = $(no-stack-protector)
+CFLAGS-s_modf-sse4_1.c = -msse4.1 -fno-builtin-modff32x -fno-builtin-modff64
+CFLAGS-s_modff-sse4_1.c = -msse4.1 -fno-builtin-modff32
 
-CFLAGS-s_modf-sse4_1.c = -msse4.1 -fno-builtin-modff32x \
-			 -fno-builtin-modff64 $(no-stack-protector)
-CFLAGS-s_modff-sse4_1.c = -msse4.1 -fno-builtin-modff32 \
-			  $(no-stack-protector)
-
-CFLAGS-s_modf-avx.c = -msse2avx -DSSE2AVX -fno-builtin-modff32x \
-		      $(no-stack-protector) -fno-builtin-modff64
-CFLAGS-s_modff-avx.c = -msse2avx -DSSE2AVX -fno-builtin-modff32 \
-		      $(no-stack-protector)
+CFLAGS-s_modf-avx.c = -msse2avx -DSSE2AVX -fno-builtin-modff32x -fno-builtin-modff64
+CFLAGS-s_modff-avx.c = -msse2avx -DSSE2AVX -fno-builtin-modff32
 endif
 
 ifeq ($(subdir),mathvec)
diff --git a/sysdeps/x86_64/fpu/multiarch/s_modf-avx.c b/sysdeps/x86_64/fpu/multiarch/s_modf-avx.c
index db32398b4a..7bae3a5f79 100644
--- a/sysdeps/x86_64/fpu/multiarch/s_modf-avx.c
+++ b/sysdeps/x86_64/fpu/multiarch/s_modf-avx.c
@@ -1 +1,5 @@
-#include <sysdeps/ieee754/dbl-64/s_modf.c>
+#include <sysdeps/x86/isa-level.h>
+#if MINIMUM_X86_ISA_LEVEL < SSE4_1_X86_ISA_LEVEL
+# define __modf __modf_avx
+# include <sysdeps/ieee754/dbl-64/s_modf.c>
+#endif
diff --git a/sysdeps/x86_64/fpu/multiarch/s_modf-sse4_1.c b/sysdeps/x86_64/fpu/multiarch/s_modf-sse4_1.c
index 6ef4c19a7e..8b9ed789d0 100644
--- a/sysdeps/x86_64/fpu/multiarch/s_modf-sse4_1.c
+++ b/sysdeps/x86_64/fpu/multiarch/s_modf-sse4_1.c
@@ -1,7 +1,6 @@
 #include <sysdeps/x86/isa-level.h>
 
-#if MINIMUM_X86_ISA_LEVEL != SSE4_1_X86_ISA_LEVEL
+#if MINIMUM_X86_ISA_LEVEL < SSE4_1_X86_ISA_LEVEL
 # define __modf __modf_sse41
+# include <sysdeps/ieee754/dbl-64/s_modf.c>
 #endif
-
-#include <sysdeps/ieee754/dbl-64/s_modf.c>
diff --git a/sysdeps/x86_64/fpu/multiarch/s_modf.c b/sysdeps/x86_64/fpu/multiarch/s_modf.c
index d65977d69a..37df8b1c9f 100644
--- a/sysdeps/x86_64/fpu/multiarch/s_modf.c
+++ b/sysdeps/x86_64/fpu/multiarch/s_modf.c
@@ -32,4 +32,6 @@
 
 libc_ifunc_redirected (__redirect_modf, __modf, IFUNC_SELECTOR ());
 libm_alias_double (__modf, modf)
+#else
+# include <sysdeps/ieee754/dbl-64/s_modf.c>
 #endif
diff --git a/sysdeps/x86_64/fpu/multiarch/s_modff-avx.c b/sysdeps/x86_64/fpu/multiarch/s_modff-avx.c
index 804b0426b7..6dd5652273 100644
--- a/sysdeps/x86_64/fpu/multiarch/s_modff-avx.c
+++ b/sysdeps/x86_64/fpu/multiarch/s_modff-avx.c
@@ -1 +1,5 @@
-#include <sysdeps/ieee754/flt-32/s_modff.c>
+#include <sysdeps/x86/isa-level.h>
+#if MINIMUM_X86_ISA_LEVEL < SSE4_1_X86_ISA_LEVEL
+# define __modff __modff_avx
+# include <sysdeps/ieee754/flt-32/s_modff.c>
+#endif
diff --git a/sysdeps/x86_64/fpu/multiarch/s_modff-sse4_1.c b/sysdeps/x86_64/fpu/multiarch/s_modff-sse4_1.c
index 0437e044f3..6ae80a1d66 100644
--- a/sysdeps/x86_64/fpu/multiarch/s_modff-sse4_1.c
+++ b/sysdeps/x86_64/fpu/multiarch/s_modff-sse4_1.c
@@ -1,7 +1,7 @@
 #include <sysdeps/x86/isa-level.h>
 
-#if MINIMUM_X86_ISA_LEVEL != SSE4_1_X86_ISA_LEVEL
+#if MINIMUM_X86_ISA_LEVEL < SSE4_1_X86_ISA_LEVEL
 # define __modff __modff_sse41
+# include <sysdeps/ieee754/flt-32/s_modff.c>
 #endif
 
-#include <sysdeps/ieee754/flt-32/s_modff.c>
diff --git a/sysdeps/x86_64/fpu/multiarch/s_modff.c b/sysdeps/x86_64/fpu/multiarch/s_modff.c
index 89d0a32c23..0d98606d7c 100644
--- a/sysdeps/x86_64/fpu/multiarch/s_modff.c
+++ b/sysdeps/x86_64/fpu/multiarch/s_modff.c
@@ -32,4 +32,6 @@
 
 libc_ifunc_redirected (__redirect_modff, __modff, IFUNC_SELECTOR ());
 libm_alias_float (__modf, modf)
+#else
+# include <sysdeps/ieee754/flt-32/s_modff.c>
 #endif
-- 
2.43.0

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