summaryrefslogtreecommitdiff
path: root/arch/arm/vdso
diff options
context:
space:
mode:
authorFangrui Song <maskray@google.com>2023-03-10 22:07:50 +0300
committerThomas Gleixner <tglx@linutronix.de>2023-03-21 23:15:34 +0300
commitaff69273af61f5d1c8fb401d6f19148d11629b41 (patch)
treeb45cbe16a6ef5789850b4fd5676dbf59682dc328 /arch/arm/vdso
parente8d018dd0257f744ca50a729e3d042cf2ec9da65 (diff)
downloadlinux-aff69273af61f5d1c8fb401d6f19148d11629b41.tar.xz
vdso: Improve cmd_vdso_check to check all dynamic relocations
The actual intention is that no dynamic relocation exists in the VDSO. For this the VDSO build validates that the resulting .so file does not have any relocations which are specified via $(ARCH_REL_TYPE_ABS) per architecture, which is fragile as e.g. ARM64 lacks an entry for R_AARCH64_RELATIVE. Aside of that ARCH_REL_TYPE_ABS is a misnomer as it checks for relative relocations too. However, some GNU ld ports produce unneeded R_*_NONE relocation entries. If a port fails to determine the exact .rel[a].dyn size, the trailing zeros become R_*_NONE relocations. E.g. ld's powerpc port recently fixed https://sourceware.org/bugzilla/show_bug.cgi?id=29540). R_*_NONE are generally a no-op in the dynamic loaders. So just ignore them. Remove the ARCH_REL_TYPE_ABS defines and just validate that the resulting .so file does not contain any R_* relocation entries except R_*_NONE. Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> # for aarch64 Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> # for vDSO, aarch64 Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Link: https://lore.kernel.org/r/20230310190750.3323802-1-maskray@google.com
Diffstat (limited to 'arch/arm/vdso')
-rw-r--r--arch/arm/vdso/Makefile4
1 files changed, 1 insertions, 3 deletions
diff --git a/arch/arm/vdso/Makefile b/arch/arm/vdso/Makefile
index a7ec06ce3785..515ca33b854c 100644
--- a/arch/arm/vdso/Makefile
+++ b/arch/arm/vdso/Makefile
@@ -1,8 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
-# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
-# the inclusion of generic Makefile.
-ARCH_REL_TYPE_ABS := R_ARM_JUMP_SLOT|R_ARM_GLOB_DAT|R_ARM_ABS32
+# Include the generic Makefile to check the built vdso.
include $(srctree)/lib/vdso/Makefile
hostprogs := vdsomunge