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Review".
This revision was automatically updated to reflect the committed changes.
Closed by commit rG223e8ca02616: Set a default number of address bits on Darwin
arm64 systems (authored by jasonmolenda).
Changed prior to commit:
https://reviews.llvm.org/D115431?vs=393213&id=393378#toc
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D115431/new/
https://reviews.llvm.org/D115431
Files:
lldb/source/DataFormatters/CXXFunctionPointer.cpp
lldb/source/Plugins/ABI/AArch64/ABIMacOSX_arm64.cpp
lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
lldb/source/Utility/ArchSpec.cpp
lldb/test/API/macosx/corefile-default-ptrauth/Makefile
lldb/test/API/macosx/corefile-default-ptrauth/TestCorefileDefaultPtrauth.py
lldb/test/API/macosx/corefile-default-ptrauth/create-corefile.c
lldb/test/API/macosx/corefile-default-ptrauth/main.c
Index: lldb/test/API/macosx/corefile-default-ptrauth/main.c
===================================================================
--- /dev/null
+++ lldb/test/API/macosx/corefile-default-ptrauth/main.c
@@ -0,0 +1,6 @@
+int main();
+int (*fmain)() = main;
+int main () {
+ return fmain();
+}
+
Index: lldb/test/API/macosx/corefile-default-ptrauth/create-corefile.c
===================================================================
--- /dev/null
+++ lldb/test/API/macosx/corefile-default-ptrauth/create-corefile.c
@@ -0,0 +1,131 @@
+#include <mach-o/loader.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <mach/machine.h>
+#include <string.h>
+#include <mach/machine/thread_state.h>
+#include <inttypes.h>
+#include <sys/syslimits.h>
+
+// Given an executable binary with
+// "fmain" (a function pointer to main)
+// "main"
+// symbols, create a fake arm64e corefile that
+// contains a memory segment for the fmain
+// function pointer, with the value of the
+// address of main() with ptrauth bits masked on.
+//
+// The corefile does not include the "addrable bits"
+// LC_NOTE, so lldb will need to fall back on its
+// default value from the Darwin arm64 ABI.
+
+int main(int argc, char **argv)
+{
+ if (argc != 3) {
+ fprintf (stderr, "usage: %s executable-binary output-file\n", argv[0]);
+ exit(1);
+ }
+ FILE *exe = fopen(argv[1], "r");
+ if (!exe) {
+ fprintf (stderr, "Unable to open executable %s for reading\n", argv[1]);
+ exit(1);
+ }
+ FILE *out = fopen(argv[2], "w");
+ if (!out) {
+ fprintf (stderr, "Unable to open %s for writing\n", argv[2]);
+ exit(1);
+ }
+
+ char buf[PATH_MAX + 6];
+ sprintf (buf, "nm '%s'", argv[1]);
+ FILE *nm = popen(buf, "r");
+ if (!nm) {
+ fprintf (stderr, "Unable to run nm on '%s'", argv[1]);
+ exit (1);
+ }
+ uint64_t main_addr = 0;
+ uint64_t fmain_addr = 0;
+ while (fgets (buf, sizeof(buf), nm)) {
+ if (strstr (buf, "_fmain")) {
+ fmain_addr = strtoul (buf, NULL, 16);
+ }
+ if (strstr (buf, "_main")) {
+ main_addr = strtoul (buf, NULL, 16);
+ }
+ }
+ pclose (nm);
+
+ if (main_addr == 0 || fmain_addr == 0) {
+ fprintf(stderr, "Unable to find address of main or fmain in %s.\n",
+ argv[1]);
+ exit (1);
+ }
+
+ // Write out a corefile with contents in this order:
+ // 1. mach header
+ // 2. LC_THREAD load command
+ // 3. LC_SEGMENT_64 load command
+ // 4. memory segment contents
+
+ // struct thread_command {
+ // uint32_t cmd;
+ // uint32_t cmdsize;
+ // uint32_t flavor
+ // uint32_t count
+ // struct XXX_thread_state state
+ int size_of_thread_cmd = 4 + 4 + 4 + 4 + sizeof (arm_thread_state64_t);
+
+ struct mach_header_64 mh;
+ mh.magic = 0xfeedfacf;
+ mh.cputype = CPU_TYPE_ARM64;
+ mh.cpusubtype = CPU_SUBTYPE_ARM64E;
+ mh.filetype = MH_CORE;
+ mh.ncmds = 2; // LC_THREAD, LC_SEGMENT_64
+ mh.sizeofcmds = size_of_thread_cmd + sizeof(struct segment_command_64);
+ mh.flags = 0;
+ mh.reserved = 0;
+
+ fwrite(&mh, sizeof (mh), 1, out);
+
+ struct segment_command_64 seg;
+ seg.cmd = LC_SEGMENT_64;
+ seg.cmdsize = sizeof(seg);
+ memset (&seg.segname, 0, 16);
+ seg.vmaddr = fmain_addr;
+ seg.vmsize = 8;
+ // Offset to segment contents
+ seg.fileoff = sizeof (mh) + size_of_thread_cmd + sizeof(seg);
+ seg.filesize = 8;
+ seg.maxprot = 3;
+ seg.initprot = 3;
+ seg.nsects = 0;
+ seg.flags = 0;
+
+ fwrite (&seg, sizeof (seg), 1, out);
+
+ uint32_t cmd = LC_THREAD;
+ fwrite (&cmd, sizeof (cmd), 1, out);
+ uint32_t cmdsize = size_of_thread_cmd;
+ fwrite (&cmdsize, sizeof (cmdsize), 1, out);
+ uint32_t flavor = ARM_THREAD_STATE64;
+ fwrite (&flavor, sizeof (flavor), 1, out);
+ // count is number of uint32_t's of the register context
+ uint32_t count = sizeof (arm_thread_state64_t) / 4;
+ fwrite (&count, sizeof (count), 1, out);
+ arm_thread_state64_t regstate;
+ memset (®state, 0, sizeof (regstate));
+ fwrite (®state, sizeof (regstate), 1, out);
+
+
+ // Or together a random PAC value from a system using 39 bits
+ // of addressing with the address of main(). lldb will need
+ // to correctly strip off the high bits to find the address of
+ // main.
+ uint64_t segment_contents = 0xe46bff0000000000 | main_addr;
+
+ fwrite (&segment_contents, sizeof (segment_contents), 1, out);
+
+ fclose (out);
+
+ exit (0);
+}
Index: lldb/test/API/macosx/corefile-default-ptrauth/TestCorefileDefaultPtrauth.py
===================================================================
--- /dev/null
+++ lldb/test/API/macosx/corefile-default-ptrauth/TestCorefileDefaultPtrauth.py
@@ -0,0 +1,50 @@
+"""Test that lldb has a default mask for addressable bits on Darwin arm64 ABI"""
+
+
+import os
+import re
+import subprocess
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class TestCorefileDefaultPtrauth(TestBase):
+
+ mydir = TestBase.compute_mydir(__file__)
+
+ @skipIf(debug_info=no_match(["dsym"]), bugnumber="This test is looking explicitly for a dSYM")
+ @skipIf(archs=no_match(['arm64','arm64e']))
+ @skipUnlessDarwin
+ def test_lc_note(self):
+ self.build()
+ self.test_exe = self.getBuildArtifact("a.out")
+ self.create_corefile = self.getBuildArtifact("create-corefile")
+ self.corefile = self.getBuildArtifact("core")
+
+ ### Create our corefile
+ retcode = call(self.create_corefile + " " + self.test_exe + " " + self.corefile, shell=True)
+
+ ## This corefile has no metadata telling us how many bits are
+ ## used for ptrauth signed function pointers. We will need lldb
+ ## to fall back on its old default value for Darwin arm64 ABIs
+ ## to correctly strip the bits.
+
+ self.target = self.dbg.CreateTarget('')
+ err = lldb.SBError()
+ self.process = self.target.LoadCore(self.corefile)
+ self.assertEqual(self.process.IsValid(), True)
+ modspec = lldb.SBModuleSpec()
+ modspec.SetFileSpec(lldb.SBFileSpec(self.test_exe, True))
+ m = self.target.AddModule(modspec)
+ self.assertTrue(m.IsValid())
+ self.target.SetModuleLoadAddress (m, 0)
+
+ # target variable should show us both the actual function
+ # pointer with ptrauth bits and the symbol it resolves to,
+ # with the ptrauth bits stripped, e.g.
+ # (int (*)(...)) fmain = 0xe46bff0100003f90 (actual=0x0000000100003f90 a.out`main at main.c:3)
+
+ self.expect("target variable fmain", substrs=['fmain = 0x', '(actual=0x', 'main at main.c'])
Index: lldb/test/API/macosx/corefile-default-ptrauth/Makefile
===================================================================
--- /dev/null
+++ lldb/test/API/macosx/corefile-default-ptrauth/Makefile
@@ -0,0 +1,12 @@
+C_SOURCES := main.c
+
+# compile a.out and create-corefile
+# create-corefile will create a custom corefile using the symbols
+# addresses from the a.out binary.
+all: a.out create-corefile
+
+create-corefile:
+ $(MAKE) -f $(MAKEFILE_RULES) EXE=create-corefile \
+ C_SOURCES=create-corefile.c
+
+include Makefile.rules
Index: lldb/source/Utility/ArchSpec.cpp
===================================================================
--- lldb/source/Utility/ArchSpec.cpp
+++ lldb/source/Utility/ArchSpec.cpp
@@ -859,6 +859,7 @@
m_triple.setArchName(llvm::StringRef(core_def->name));
if (arch_type == eArchTypeMachO) {
m_triple.setVendor(llvm::Triple::Apple);
+ m_triple.setObjectFormat(llvm::Triple::MachO);
// Don't set the OS. It could be simulator, macosx, ios, watchos,
// tvos, bridgeos. We could get close with the cpu type - but we
Index: lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
===================================================================
--- lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
+++ lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
@@ -5154,17 +5154,7 @@
}
if (!found_any) {
- if (header.filetype == MH_KEXT_BUNDLE) {
- base_triple.setVendor(llvm::Triple::Apple);
- add_triple(base_triple);
- } else {
- // We didn't find a LC_VERSION_MIN load command and this isn't a KEXT
- // so lets not say our Vendor is Apple, leave it as an unspecified
- // unknown.
- base_triple.setVendor(llvm::Triple::UnknownVendor);
- base_triple.setVendorName(llvm::StringRef());
- add_triple(base_triple);
- }
+ add_triple(base_triple);
}
}
Index: lldb/source/Plugins/ABI/AArch64/ABIMacOSX_arm64.cpp
===================================================================
--- lldb/source/Plugins/ABI/AArch64/ABIMacOSX_arm64.cpp
+++ lldb/source/Plugins/ABI/AArch64/ABIMacOSX_arm64.cpp
@@ -817,6 +817,16 @@
lldb::addr_t ABIMacOSX_arm64::FixAddress(addr_t pc, addr_t mask) {
lldb::addr_t pac_sign_extension = 0x0080000000000000ULL;
+ // Darwin systems originally couldn't determine the proper value
+ // dynamically, so the most common value was hardcoded. This has
+ // largely been cleaned up, but there are still a handful of
+ // environments that assume the default value is set to this value
+ // and there's no dynamic value to correct it.
+ // When no mask is specified, set it to 39 bits of addressing (0..38).
+ if (mask == 0) {
+ // ~((1ULL<<39)-1)
+ mask = 0xffffff8000000000;
+ }
return (pc & pac_sign_extension) ? pc | mask : pc & (~mask);
}
Index: lldb/source/DataFormatters/CXXFunctionPointer.cpp
===================================================================
--- lldb/source/DataFormatters/CXXFunctionPointer.cpp
+++ lldb/source/DataFormatters/CXXFunctionPointer.cpp
@@ -9,6 +9,7 @@
#include "lldb/DataFormatters/CXXFunctionPointer.h"
#include "lldb/Core/ValueObject.h"
+#include "lldb/Target/ABI.h"
#include "lldb/Target/SectionLoadList.h"
#include "lldb/Target/Target.h"
#include "lldb/Utility/Stream.h"
@@ -38,8 +39,34 @@
Address so_addr;
Target *target = exe_ctx.GetTargetPtr();
if (target && !target->GetSectionLoadList().IsEmpty()) {
- if (target->GetSectionLoadList().ResolveLoadAddress(func_ptr_address,
- so_addr)) {
+ target->GetSectionLoadList().ResolveLoadAddress(func_ptr_address,
+ so_addr);
+ if (so_addr.GetSection() == nullptr) {
+ // If we have an address that doesn't correspond to any symbol,
+ // it might have authentication bits. Strip them & see if it
+ // now points to a symbol -- if so, do the SymbolContext lookup
+ // based on the stripped address.
+ // If we find a symbol with the ptrauth bits stripped, print the
+ // raw value into the stream, and replace the Address with the
+ // one that points to a symbol for a fuller description.
+ if (Process *process = exe_ctx.GetProcessPtr()) {
+ if (ABISP abi_sp = process->GetABI()) {
+ addr_t fixed_addr = abi_sp->FixCodeAddress(func_ptr_address);
+ if (fixed_addr != func_ptr_address) {
+ Address test_address;
+ test_address.SetLoadAddress(fixed_addr, target);
+ if (test_address.GetSection() != nullptr) {
+ int addrsize = target->GetArchitecture().GetAddressByteSize();
+ sstr.Printf("actual=0x%*.*" PRIx64 " ", addrsize * 2,
+ addrsize * 2, fixed_addr);
+ so_addr = test_address;
+ }
+ }
+ }
+ }
+ }
+
+ if (so_addr.IsValid()) {
so_addr.Dump(&sstr, exe_ctx.GetBestExecutionContextScope(),
Address::DumpStyleResolvedDescription,
Address::DumpStyleSectionNameOffset);
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