configure,meson: support Control-Flow Integrity
This patch adds a flag to enable/disable control flow integrity checks
on indirect function calls.
This feature only allows indirect function calls at runtime to functions
with compatible signatures.
This feature is only provided by LLVM/Clang, and depends on link-time
optimization which is currently supported only with LLVM/Clang >= 6.0
We also add an option to enable a debugging version of cfi, with verbose
output in case of a CFI violation.
CFI on indirect function calls does not support calls to functions in
shared libraries (since they were not known at compile time), and such
calls are forbidden. QEMU relies on dlopen/dlsym when using modules,
so we make modules incompatible with CFI.
All the checks are performed in meson.build. configure is only used to
forward the flags to meson
Signed-off-by: Daniele Buono <dbuono@linux.vnet.ibm.com>
Message-Id: <20201204230615.2392-5-dbuono@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/configure b/configure
index b6fb188..5c8f3e5 100755
--- a/configure
+++ b/configure
@@ -411,6 +411,8 @@
coroutine_pool="$default_feature"
debug_stack_usage="no"
crypto_afalg="no"
+cfi="false"
+cfi_debug="false"
seccomp="$default_feature"
glusterfs="$default_feature"
glusterfs_xlator_opt="no"
@@ -1195,6 +1197,16 @@
;;
--disable-safe-stack) safe_stack="no"
;;
+ --enable-cfi)
+ cfi="true";
+ lto="true";
+ ;;
+ --disable-cfi) cfi="false"
+ ;;
+ --enable-cfi-debug) cfi_debug="true"
+ ;;
+ --disable-cfi-debug) cfi_debug="false"
+ ;;
--disable-curses) curses="disabled"
;;
--enable-curses) curses="enabled"
@@ -1788,7 +1800,13 @@
sparse sparse checker
safe-stack SafeStack Stack Smash Protection. Depends on
clang/llvm >= 3.7 and requires coroutine backend ucontext.
-
+ cfi Enable Control-Flow Integrity for indirect function calls.
+ In case of a cfi violation, QEMU is terminated with SIGILL
+ Depends on lto and is incompatible with modules
+ Automatically enables Link-Time Optimization (lto)
+ cfi-debug In case of a cfi violation, a message containing the line that
+ triggered the error is written to stderr. After the error,
+ QEMU is still terminated with SIGILL
gnutls GNUTLS cryptography support
nettle nettle cryptography support
gcrypt libgcrypt cryptography support
@@ -6971,7 +6989,7 @@
-Db_pie=$(if test "$pie" = yes; then echo true; else echo false; fi) \
${staticpic:+-Db_staticpic=$staticpic} \
-Db_coverage=$(if test "$gcov" = yes; then echo true; else echo false; fi) \
- -Db_lto=$lto \
+ -Db_lto=$lto -Dcfi=$cfi -Dcfi_debug=$cfi_debug \
-Dmalloc=$malloc -Dmalloc_trim=$malloc_trim -Dsparse=$sparse \
-Dkvm=$kvm -Dhax=$hax -Dwhpx=$whpx -Dhvf=$hvf \
-Dxen=$xen -Dxen_pci_passthrough=$xen_pci_passthrough -Dtcg=$tcg \
