glibc/sysdeps/x86/Makefile
Florian Weimer 681900d296 x86: Harden printf against non-normal long double values (bug 26649)
The behavior of isnan/__builtin_isnan on bit patterns that do not
correspond to something that the CPU would produce from valid inputs
is currently under-defined in the toolchain. (The GCC built-in and
glibc disagree.)

The isnan check in PRINTF_FP_FETCH in stdio-common/printf_fp.c
assumes the GCC behavior that returns true for non-normal numbers
which are not specified as NaN. (The glibc implementation returns
false for such numbers.)

At present, passing non-normal numbers to __mpn_extract_long_double
causes this function to produce irregularly shaped multi-precision
integers, triggering undefined behavior in __printf_fp_l.

With GCC 10 and glibc 2.32, this behavior is not visible because
__builtin_isnan is used, which avoids calling
__mpn_extract_long_double in this case.  This commit updates the
implementation of __mpn_extract_long_double so that regularly shaped
multi-precision integers are produced in this case, avoiding
undefined behavior in __printf_fp_l.
2020-09-22 19:07:49 +02:00

154 lines
5.8 KiB
Makefile

ifeq ($(subdir),csu)
gen-as-const-headers += cpu-features-offsets.sym
endif
ifeq ($(subdir),elf)
sysdep-dl-routines += dl-get-cpu-features
sysdep_headers += sys/platform/x86.h
tests += tst-get-cpu-features tst-get-cpu-features-static \
tst-cpu-features-cpuinfo tst-cpu-features-supports
tests-static += tst-get-cpu-features-static
endif
ifeq ($(subdir),math)
tests += tst-ldbl-nonnormal-printf
endif # $(subdir) == math
ifeq ($(subdir),setjmp)
gen-as-const-headers += jmp_buf-ssp.sym
sysdep_routines += __longjmp_cancel
endif
ifeq ($(subdir),string)
sysdep_routines += cacheinfo
endif
ifneq ($(enable-cet),no)
ifeq ($(subdir),elf)
sysdep-dl-routines += dl-cet
tests += tst-cet-legacy-1 tst-cet-legacy-1a tst-cet-legacy-2 \
tst-cet-legacy-2a tst-cet-legacy-3 tst-cet-legacy-4 \
tst-cet-legacy-5a tst-cet-legacy-6a tst-cet-legacy-7 \
tst-cet-legacy-8
tst-cet-legacy-1a-ARGS = -- $(host-test-program-cmd)
ifneq (no,$(have-tunables))
tests += tst-cet-legacy-4a tst-cet-legacy-4b tst-cet-legacy-4c \
tst-cet-legacy-5b tst-cet-legacy-6b
endif
modules-names += tst-cet-legacy-mod-1 tst-cet-legacy-mod-2 \
tst-cet-legacy-mod-4 tst-cet-legacy-mod-5a \
tst-cet-legacy-mod-5b tst-cet-legacy-mod-5c \
tst-cet-legacy-mod-6a tst-cet-legacy-mod-6b \
tst-cet-legacy-mod-6c
CFLAGS-tst-cet-legacy-2.c += -fcf-protection=branch
CFLAGS-tst-cet-legacy-2a.c += -fcf-protection
CFLAGS-tst-cet-legacy-mod-1.c += -fcf-protection=none
CFLAGS-tst-cet-legacy-mod-2.c += -fcf-protection=none
CFLAGS-tst-cet-legacy-3.c += -fcf-protection=none
CFLAGS-tst-cet-legacy-4.c += -fcf-protection=branch
CFLAGS-tst-cet-legacy-4a.c += -fcf-protection
CFLAGS-tst-cet-legacy-4b.c += -fcf-protection
CFLAGS-tst-cet-legacy-mod-4.c += -fcf-protection=none
CFLAGS-tst-cet-legacy-5a.c += -fcf-protection -mshstk
ifeq ($(enable-cet),permissive)
CPPFLAGS-tst-cet-legacy-5a.c += -DCET_IS_PERMISSIVE=1
endif
CFLAGS-tst-cet-legacy-5b.c += -fcf-protection -mshstk
CPPFLAGS-tst-cet-legacy-5b.c += -DCET_DISABLED_BY_ENV=1
CFLAGS-tst-cet-legacy-mod-5a.c += -fcf-protection=branch
CFLAGS-tst-cet-legacy-mod-5b.c += -fcf-protection
CFLAGS-tst-cet-legacy-mod-5c.c += -fcf-protection
CFLAGS-tst-cet-legacy-6a.c += -fcf-protection -mshstk
ifeq ($(enable-cet),permissive)
CPPFLAGS-tst-cet-legacy-6a.c += -DCET_IS_PERMISSIVE=1
endif
CFLAGS-tst-cet-legacy-6b.c += -fcf-protection -mshstk
CPPFLAGS-tst-cet-legacy-6b.c += -DCET_DISABLED_BY_ENV=1
CFLAGS-tst-cet-legacy-mod-6a.c += -fcf-protection=branch
CFLAGS-tst-cet-legacy-mod-6b.c += -fcf-protection
CFLAGS-tst-cet-legacy-mod-6c.c += -fcf-protection
CFLAGS-tst-cet-legacy-7.c += -fcf-protection=none
CFLAGS-tst-cet-legacy-8.c += -mshstk
$(objpfx)tst-cet-legacy-1: $(objpfx)tst-cet-legacy-mod-1.so \
$(objpfx)tst-cet-legacy-mod-2.so
$(objpfx)tst-cet-legacy-1a: $(objpfx)tst-cet-legacy-mod-1.so \
$(objpfx)tst-cet-legacy-mod-2.so
$(objpfx)tst-cet-legacy-2: $(objpfx)tst-cet-legacy-mod-2.so $(libdl)
$(objpfx)tst-cet-legacy-2.out: $(objpfx)tst-cet-legacy-mod-1.so
$(objpfx)tst-cet-legacy-2a: $(objpfx)tst-cet-legacy-mod-2.so $(libdl)
$(objpfx)tst-cet-legacy-2a.out: $(objpfx)tst-cet-legacy-mod-1.so
$(objpfx)tst-cet-legacy-4: $(libdl)
$(objpfx)tst-cet-legacy-4.out: $(objpfx)tst-cet-legacy-mod-4.so
$(objpfx)tst-cet-legacy-5a: $(libdl)
$(objpfx)tst-cet-legacy-5a.out: $(objpfx)tst-cet-legacy-mod-5a.so \
$(objpfx)tst-cet-legacy-mod-5b.so
$(objpfx)tst-cet-legacy-mod-5a.so: $(objpfx)tst-cet-legacy-mod-5c.so
$(objpfx)tst-cet-legacy-mod-5b.so: $(objpfx)tst-cet-legacy-mod-5c.so
$(objpfx)tst-cet-legacy-6a: $(libdl)
$(objpfx)tst-cet-legacy-6a.out: $(objpfx)tst-cet-legacy-mod-6a.so \
$(objpfx)tst-cet-legacy-mod-6b.so
$(objpfx)tst-cet-legacy-mod-6a.so: $(objpfx)tst-cet-legacy-mod-6c.so
$(objpfx)tst-cet-legacy-mod-6b.so: $(objpfx)tst-cet-legacy-mod-6c.so
LDFLAGS-tst-cet-legacy-mod-6c.so = -Wl,--enable-new-dtags,-z,nodelete
ifneq (no,$(have-tunables))
$(objpfx)tst-cet-legacy-4a: $(libdl)
$(objpfx)tst-cet-legacy-4a.out: $(objpfx)tst-cet-legacy-mod-4.so
tst-cet-legacy-4a-ENV = GLIBC_TUNABLES=glibc.cpu.x86_shstk=permissive
$(objpfx)tst-cet-legacy-4b: $(libdl)
$(objpfx)tst-cet-legacy-4b.out: $(objpfx)tst-cet-legacy-mod-4.so
tst-cet-legacy-4b-ENV = GLIBC_TUNABLES=glibc.cpu.x86_shstk=on
$(objpfx)tst-cet-legacy-4c: $(libdl)
$(objpfx)tst-cet-legacy-4c.out: $(objpfx)tst-cet-legacy-mod-4.so
tst-cet-legacy-4c-ENV = GLIBC_TUNABLES=glibc.cpu.x86_shstk=off
$(objpfx)tst-cet-legacy-5b: $(libdl)
$(objpfx)tst-cet-legacy-5b.out: $(objpfx)tst-cet-legacy-mod-5a.so \
$(objpfx)tst-cet-legacy-mod-5b.so
tst-cet-legacy-5b-ENV = GLIBC_TUNABLES=glibc.cpu.hwcaps=-IBT,-SHSTK
$(objpfx)tst-cet-legacy-6b: $(libdl)
$(objpfx)tst-cet-legacy-6b.out: $(objpfx)tst-cet-legacy-mod-6a.so \
$(objpfx)tst-cet-legacy-mod-6b.so
tst-cet-legacy-6b-ENV = GLIBC_TUNABLES=glibc.cpu.hwcaps=-IBT,-SHSTK
endif
endif
# Add -fcf-protection to CFLAGS when CET is enabled.
CFLAGS-.o += -fcf-protection
CFLAGS-.os += -fcf-protection
CFLAGS-.op += -fcf-protection
CFLAGS-.oS += -fcf-protection
# Compile assembly codes with <cet.h> when CET is enabled.
asm-CPPFLAGS += -fcf-protection -include cet.h
ifeq ($(subdir),elf)
ifeq (yes,$(build-shared))
tests-special += $(objpfx)check-cet.out
endif
# FIXME: Can't use all-built-dso in elf/Makefile since this file is
# processed before elf/Makefile. Duplicate it here.
cet-built-dso := $(common-objpfx)elf/ld.so $(common-objpfx)libc.so \
$(filter-out $(common-objpfx)linkobj/libc.so, \
$(sort $(wildcard $(addprefix $(common-objpfx), \
*/lib*.so \
iconvdata/*.so))))
$(cet-built-dso:=.note): %.note: %
@rm -f $@T
LC_ALL=C $(READELF) -n $< > $@T
test -s $@T
mv -f $@T $@
common-generated += $(cet-built-dso:$(common-objpfx)%=%.note)
$(objpfx)check-cet.out: $(..)sysdeps/x86/check-cet.awk \
$(cet-built-dso:=.note)
LC_ALL=C $(AWK) -f $^ > $@; \
$(evaluate-test)
generated += check-cet.out
endif
endif