Run ld.so through check-localplt, check-textrel, and check-execstack.
diff mbox

Message ID 545184B9.2000305@redhat.com
State New
Headers show

Commit Message

Carlos O'Donell Oct. 30, 2014, 12:22 a.m. UTC
On 10/24/2014 05:40 PM, Roland McGrath wrote:
> It's a surprise to me too, and I had to check to convince myself it really
> wasn't tested somehow.  I don't see any reason it shouldn't be per se.  Add
> it to the list and verify nothing goes wrong.  But there are reasons it's
> far less likely ever to be a problem.  ld.so has no dependencies and is
> built with -z defs, so it can never have undefined references and can never
> have PLT entries for anything but its own exported symbols (unless the
> linker grows new bugs).  There is a very small set of exported symbols
> (elf/Versions) that almost never changes.

How is this then?

I've added ld.so to the check-localplt, check-textrel, and check-execstack
tests. It fails only in check-localplt because there are 6 symbols which
need to be accounted.

Based on my analysis every architecture that has TLS will have:
__tls_get_addr, with the exception of i386 which has ___tls_get_addr,
and ppc64* which doesn't have it at all as a consequence of the ABI.
All machines should also have __libc_memalign, malloc, calloc, realloc,
and free in ld.so's PLT entry list.

No regressions on x86-64 and i386.

Not tested on any other machines. I expect the machine maintainers
to cleanup and I'll email them.

OK?

Cheers,
Carlos.

2014-10-29  Carlos O'Donell  <carlos@redhat.com>
 
	* elf/Makefile (all-built-dso): Add $(common-objpfx)elf/ld.so.
	(localplt-build-dso): Add elf/ld.so.
	* sysdeps/unix/sysv/linux/i386/localplt.data: Add ___tls_get_addr,
	__libc_memalign, malloc, calloc, realloc, and free for ld.so.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data: Add
	__libc_memalign, malloc, calloc, realloc, and free for ld.so.
	* sysdeps/generic/localplt.data: Add __tls_get_addr, __libc_memalign,
	malloc, calloc, realloc and free for ld.so.
	* sysdeps/unix/sysv/linux/aarch64/localplt.data: Likewise.
	* sysdeps/unix/sysv/linux/alpha/localplt.data: Likewise.
	* sysdeps/unix/sysv/linux/arm/localplt.data: Likewise.
	* sysdeps/unix/sysv/linux/ia64/localplt.data: Likewise.
	* sysdeps/unix/sysv/linux/m68k/localplt.data: Likewise.
	* sysdeps/unix/sysv/linux/microblaze/localplt.data: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data:
	Likewise.
	* sysdeps/unix/sysv/linux/s390/localplt.data: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data: Likewise.

---

Cheers,
Carlos.

Comments

Roland McGrath Oct. 30, 2014, 7:42 p.m. UTC | #1
OK by me

Patch
diff mbox

diff --git a/elf/Makefile b/elf/Makefile
index 94074f3..34f0b1f 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -904,7 +904,7 @@  CFLAGS-tst-pie2.c += $(pie-ccflag)
 $(objpfx)tst-pie1: $(objpfx)tst-piemod1.so
 
 ifeq (yes,$(build-shared))
-all-built-dso := $(common-objpfx)libc.so \
+all-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 \
@@ -963,6 +963,7 @@  common-generated += $(all-built-dso:$(common-objpfx)%=%.jmprel)
 
 localplt-built-dso := $(addprefix $(common-objpfx),\
 				  libc.so \
+				  elf/ld.so \
 				  math/libm.so \
 				  rt/librt.so \
 				  dlfcn/libdl.so \
diff --git a/sysdeps/generic/localplt.data b/sysdeps/generic/localplt.data
index d296519..d7d6734 100644
--- a/sysdeps/generic/localplt.data
+++ b/sysdeps/generic/localplt.data
@@ -7,3 +7,12 @@  libc.so: malloc
 libc.so: memalign
 libc.so: realloc
 libm.so: matherr
+# The dynamic loader needs __tls_get_addr for TLS, and uses __libc_memalign
+# internally to allocate aligned TLS storage. The other malloc family of
+# functions are expected to allow user symbol interposition.
+ld.so: __tls_get_addr
+ld.so: __libc_memalign
+ld.so: malloc
+ld.so: calloc
+ld.so: realloc
+ld.so: free
diff --git a/sysdeps/unix/sysv/linux/aarch64/localplt.data b/sysdeps/unix/sysv/linux/aarch64/localplt.data
index dfca9a7..a3392d3 100644
--- a/sysdeps/unix/sysv/linux/aarch64/localplt.data
+++ b/sysdeps/unix/sysv/linux/aarch64/localplt.data
@@ -12,3 +12,12 @@  libm.so: matherr
 libm.so: __signbit
 libm.so: __signbitf
 libm.so: __signbitl
+# The dynamic loader needs __tls_get_addr for TLS, and uses __libc_memalign
+# internally to allocate aligned TLS storage. The other malloc family of
+# functions are expected to allow user symbol interposition.
+ld.so: __tls_get_addr
+ld.so: __libc_memalign
+ld.so: malloc
+ld.so: calloc
+ld.so: realloc
+ld.so: free
diff --git a/sysdeps/unix/sysv/linux/alpha/localplt.data b/sysdeps/unix/sysv/linux/alpha/localplt.data
index 6b2e515..e2a4311 100644
--- a/sysdeps/unix/sysv/linux/alpha/localplt.data
+++ b/sysdeps/unix/sysv/linux/alpha/localplt.data
@@ -24,3 +24,12 @@  libm.so: matherr
 # We used to offer inline functions that used this, so it must be exported.
 # Ought to reorg things such that carg isn't thus forced to use a plt.
 libm.so: __atan2
+# The dynamic loader needs __tls_get_addr for TLS, and uses __libc_memalign
+# internally to allocate aligned TLS storage. The other malloc family of
+# functions are expected to allow user symbol interposition.
+ld.so: __tls_get_addr
+ld.so: __libc_memalign
+ld.so: malloc
+ld.so: calloc
+ld.so: realloc
+ld.so: free
diff --git a/sysdeps/unix/sysv/linux/arm/localplt.data b/sysdeps/unix/sysv/linux/arm/localplt.data
index 109522e..85160bd 100644
--- a/sysdeps/unix/sysv/linux/arm/localplt.data
+++ b/sysdeps/unix/sysv/linux/arm/localplt.data
@@ -11,3 +11,12 @@  libm.so: __signbitf
 libm.so: matherr
 libpthread.so: __errno_location
 libpthread.so: raise
+# The dynamic loader needs __tls_get_addr for TLS, and uses __libc_memalign
+# internally to allocate aligned TLS storage. The other malloc family of
+# functions are expected to allow user symbol interposition.
+ld.so: __tls_get_addr
+ld.so: __libc_memalign
+ld.so: malloc
+ld.so: calloc
+ld.so: realloc
+ld.so: free
diff --git a/sysdeps/unix/sysv/linux/i386/localplt.data b/sysdeps/unix/sysv/linux/i386/localplt.data
index 8fb56b6..009797b 100644
--- a/sysdeps/unix/sysv/linux/i386/localplt.data
+++ b/sysdeps/unix/sysv/linux/i386/localplt.data
@@ -5,3 +5,14 @@  libc.so: malloc
 libc.so: memalign
 libc.so: realloc
 libm.so: matherr
+# The dynamic loader needs ___tls_get_addr for TLS, and uses __libc_memalign
+# internally to allocate aligned TLS storage. The other malloc family of
+# functions are expected to allow user symbol interposition.
+# Note that it is triple underscore for ___tls_get_addr e.g. the alternate
+# ABI.
+ld.so: ___tls_get_addr
+ld.so: __libc_memalign
+ld.so: malloc
+ld.so: calloc
+ld.so: realloc
+ld.so: free
diff --git a/sysdeps/unix/sysv/linux/ia64/localplt.data b/sysdeps/unix/sysv/linux/ia64/localplt.data
index ba48816..bc2ce41 100644
--- a/sysdeps/unix/sysv/linux/ia64/localplt.data
+++ b/sysdeps/unix/sysv/linux/ia64/localplt.data
@@ -6,3 +6,12 @@  libc.so: realloc
 libm.so: matherr
 libm.so: matherrf
 libm.so: matherrl
+# The dynamic loader needs __tls_get_addr for TLS, and uses __libc_memalign
+# internally to allocate aligned TLS storage. The other malloc family of
+# functions are expected to allow user symbol interposition.
+ld.so: __tls_get_addr
+ld.so: __libc_memalign
+ld.so: malloc
+ld.so: calloc
+ld.so: realloc
+ld.so: free
diff --git a/sysdeps/unix/sysv/linux/m68k/localplt.data b/sysdeps/unix/sysv/linux/m68k/localplt.data
index d266b8f..15a9fe5 100644
--- a/sysdeps/unix/sysv/linux/m68k/localplt.data
+++ b/sysdeps/unix/sysv/linux/m68k/localplt.data
@@ -6,3 +6,12 @@  libc.so: malloc
 libc.so: memalign
 libc.so: realloc
 libm.so: matherr
+# The dynamic loader needs __tls_get_addr for TLS, and uses __libc_memalign
+# internally to allocate aligned TLS storage. The other malloc family of
+# functions are expected to allow user symbol interposition.
+ld.so: __tls_get_addr
+ld.so: __libc_memalign
+ld.so: malloc
+ld.so: calloc
+ld.so: realloc
+ld.so: free
diff --git a/sysdeps/unix/sysv/linux/microblaze/localplt.data b/sysdeps/unix/sysv/linux/microblaze/localplt.data
index 6dd5bcb..f488c95 100644
--- a/sysdeps/unix/sysv/linux/microblaze/localplt.data
+++ b/sysdeps/unix/sysv/linux/microblaze/localplt.data
@@ -9,3 +9,12 @@  libm.so: __signbit
 libm.so: __signbitf
 libm.so: matherr
 libpthread.so: __errno_location
+# The dynamic loader needs __tls_get_addr for TLS, and uses __libc_memalign
+# internally to allocate aligned TLS storage. The other malloc family of
+# functions are expected to allow user symbol interposition.
+ld.so: __tls_get_addr
+ld.so: __libc_memalign
+ld.so: malloc
+ld.so: calloc
+ld.so: realloc
+ld.so: free
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data
index 8fb56b6..619b417 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data
@@ -5,3 +5,12 @@  libc.so: malloc
 libc.so: memalign
 libc.so: realloc
 libm.so: matherr
+# The dynamic loader needs __tls_get_addr for TLS, and uses __libc_memalign
+# internally to allocate aligned TLS storage. The other malloc family of
+# functions are expected to allow user symbol interposition.
+ld.so: __tls_get_addr
+ld.so: __libc_memalign
+ld.so: malloc
+ld.so: calloc
+ld.so: realloc
+ld.so: free
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data
index 6332a00..78ecd4a 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data
@@ -38,3 +38,12 @@  libm.so: __signbitl
 libm.so: copysignl ?
 libm.so: fabsl
 libm.so: matherr
+# The dynamic loader needs __tls_get_addr for TLS, and uses __libc_memalign
+# internally to allocate aligned TLS storage. The other malloc family of
+# functions are expected to allow user symbol interposition.
+ld.so: __tls_get_addr
+ld.so: __libc_memalign
+ld.so: malloc
+ld.so: calloc
+ld.so: realloc
+ld.so: free
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data
index 2219aa9..75bcee6 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data
@@ -4,3 +4,12 @@  libc.so: malloc
 libc.so: memalign
 libc.so: realloc
 libm.so: matherr
+# The dynamic loader uses __libc_memalign internally to allocate aligned
+# TLS storage. The other malloc family of functions are expected to
+# allow user symbol interposition. Note that because of the way the TLS
+# ABI works there is no PLT call to __tls_get_addr on ppc64 and ppc64le.
+ld.so: __libc_memalign
+ld.so: malloc
+ld.so: calloc
+ld.so: realloc
+ld.so: free
diff --git a/sysdeps/unix/sysv/linux/s390/localplt.data b/sysdeps/unix/sysv/linux/s390/localplt.data
index 8fb56b6..619b417 100644
--- a/sysdeps/unix/sysv/linux/s390/localplt.data
+++ b/sysdeps/unix/sysv/linux/s390/localplt.data
@@ -5,3 +5,12 @@  libc.so: malloc
 libc.so: memalign
 libc.so: realloc
 libm.so: matherr
+# The dynamic loader needs __tls_get_addr for TLS, and uses __libc_memalign
+# internally to allocate aligned TLS storage. The other malloc family of
+# functions are expected to allow user symbol interposition.
+ld.so: __tls_get_addr
+ld.so: __libc_memalign
+ld.so: malloc
+ld.so: calloc
+ld.so: realloc
+ld.so: free
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data b/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data
index 15ba18b..81c1650 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data
@@ -15,3 +15,12 @@  libc.so: malloc
 libc.so: memalign
 libc.so: realloc
 libm.so: matherr
+# The dynamic loader needs __tls_get_addr for TLS, and uses __libc_memalign
+# internally to allocate aligned TLS storage. The other malloc family of
+# functions are expected to allow user symbol interposition.
+ld.so: __tls_get_addr
+ld.so: __libc_memalign
+ld.so: malloc
+ld.so: calloc
+ld.so: realloc
+ld.so: free
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data b/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data
index 6f1769c..d6f9e02 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data
@@ -17,3 +17,12 @@  libc.so: malloc
 libc.so: memalign
 libc.so: realloc
 libm.so: matherr
+# The dynamic loader needs __tls_get_addr for TLS, and uses __libc_memalign
+# internally to allocate aligned TLS storage. The other malloc family of
+# functions are expected to allow user symbol interposition.
+ld.so: __tls_get_addr
+ld.so: __libc_memalign
+ld.so: malloc
+ld.so: calloc
+ld.so: realloc
+ld.so: free