https://github.com/libffi/libffi/issues/855 https://github.com/libffi/libffi/commit/f64141ee3f9e455a060bd09e9ab72b6c94653d7c From f64141ee3f9e455a060bd09e9ab72b6c94653d7c Mon Sep 17 00:00:00 2001 From: Bill Roberts <152999275+billatarm@users.noreply.github.com> Date: Tue, 19 Mar 2024 11:44:55 -0500 Subject: [PATCH] Fix bti support (#830) * bti: add identifier to ffi_closure_SYSV_V_alt This was missing BTI_C identifier. Old Code: ffi_closure_SYSV_V_alt: 0000fffff7f70500: ldr x17, [sp, #8] Signed-off-by: Bill Roberts <bill.roberts@arm.com> * testsuite: fix whitespace in Makefile.am Signed-off-by: Bill Roberts <bill.roberts@arm.com> * aarch64: correct comment describing BTI The comment is incorrect, BTI is enabled per mapping via mprotect with PROT_BTI flag set, not per-process. When the loader loads the library, if the GNU Notes section is missing this, PROT_BTI will not be enabled for that mapping, but is independent of other mappings. Signed-off-by: Bill Roberts <bill.roberts@arm.com> --------- Signed-off-by: Bill Roberts <bill.roberts@arm.com> --- src/aarch64/sysv.S | 4 +++- testsuite/Makefile.am | 2 +- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/src/aarch64/sysv.S b/src/aarch64/sysv.S index fdd0e8b7..60cfa505 100644 --- a/src/aarch64/sysv.S +++ b/src/aarch64/sysv.S @@ -68,7 +68,7 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #define BTI_J hint #36 /* * The ELF Notes section needs to indicate if BTI is supported, as the first ELF loaded that doesn't - * declare this support disables it for the whole process. + * declare this support disables it for memory region containing the loaded library. */ # define GNU_PROPERTY_AARCH64_BTI (1 << 0) /* Has Branch Target Identification */ .text @@ -527,6 +527,7 @@ L(do_closure): #if defined(FFI_EXEC_STATIC_TRAMP) .align 4 CNAME(ffi_closure_SYSV_V_alt): + BTI_C /* See the comments above trampoline_code_table. */ ldr x17, [sp, #8] /* Load closure in x17 */ add sp, sp, #16 /* Restore the stack */ @@ -541,6 +542,7 @@ CNAME(ffi_closure_SYSV_V_alt): .align 4 CNAME(ffi_closure_SYSV_alt): + BTI_C /* See the comments above trampoline_code_table. */ ldr x17, [sp, #8] /* Load closure in x17 */ add sp, sp, #16 /* Restore the stack */ diff --git a/testsuite/Makefile.am b/testsuite/Makefile.am index d286cf7f..6ba98e12 100644 --- a/testsuite/Makefile.am +++ b/testsuite/Makefile.am @@ -8,7 +8,7 @@ CLEANFILES = *.exe core* *.log *.sum EXTRA_DIST = config/default.exp emscripten/build.sh emscripten/conftest.py \ emscripten/node-tests.sh emscripten/test.html emscripten/test_libffi.py \ - emscripten/build-tests.sh lib/libffi.exp lib/target-libpath.exp \ + emscripten/build-tests.sh lib/libffi.exp lib/target-libpath.exp \ lib/wrapper.exp libffi.bhaible/Makefile libffi.bhaible/README \ libffi.bhaible/alignof.h libffi.bhaible/bhaible.exp libffi.bhaible/test-call.c \ libffi.bhaible/test-callback.c libffi.bhaible/testcases.c libffi.call/align_mixed.c \