[lldb][Mach-O] Read dyld_all_image_infos addr from `main bin spec` LC_NOTE (#127156)

Mach-O corefiles have LC_NOTE metadata, one LC_NOTE that lldb recognizes
is `main bin spec` which can specify that this is a kernel corefile,
userland corefile, or firmware/standalone corefile. With a userland
corefile, the LC_NOTE would specify the virtual address of the dyld
binary's Mach-O header. lldb would create a Module from that in-memory
binary, find the `dyld_all_image_infos` object in dyld's DATA segment,
and use that object to find all of the binaries present in the corefile.

ProcessMachCore takes the metadata from this LC_NOTE and passes the
address to the DynamicLoader plugin via its `GetImageInfoAddress()`
method, so the DynamicLoader can find all of the binaries and load them
in the Target at their correct virtual addresses.

We have a corefile creator who would prefer to specify the address of
`dyld_all_image_infos` directly, instead of specifying the address of
dyld and parsing that to find the object. DynamicLoaderMacOSX, the
DynamicLoader plugin being used here, will accept either a dyld virtual
address or a `dyld_all_image_infos` virtual address from
ProcessMachCore, and do the correct thing with either value.

lldb's process save-core mach-o corefile reader will continue to specify
the virtual address of the dyld binary.

rdar://144322688

1 files changed, 10 insertions, 1 deletions

diff --git a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
index 4e356a7..a19322f 100644
--- a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
+++ b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
@@ -5599,9 +5599,13 @@ bool ObjectFileMachO::GetCorefileMainBinaryInfo(addr_t &value,
       // struct main_bin_spec
       // {
       //     uint32_t version;       // currently 2
-      //     uint32_t type;          // 0 == unspecified, 1 == kernel,
+      //     uint32_t type;          // 0 == unspecified,
+      //                             // 1 == kernel
       //                             // 2 == user process,
+      //                                     dyld mach-o binary addr
       //                             // 3 == standalone binary
+      //                             // 4 == user process,
+      //                             //      dyld_all_image_infos addr
       //     uint64_t address;       // UINT64_MAX if address not specified
       //     uint64_t slide;         // slide, UINT64_MAX if unspecified
       //                             // 0 if no slide needs to be applied to
@@ -5652,6 +5656,7 @@ bool ObjectFileMachO::GetCorefileMainBinaryInfo(addr_t &value,
           // convert the "main bin spec" type into our
           // ObjectFile::BinaryType enum
           const char *typestr = "unrecognized type";
+          type = eBinaryTypeInvalid;
           switch (binspec_type) {
           case 0:
             type = eBinaryTypeUnknown;
@@ -5669,6 +5674,10 @@ bool ObjectFileMachO::GetCorefileMainBinaryInfo(addr_t &value,
             type = eBinaryTypeStandalone;
             typestr = "standalone";
             break;
+          case 4:
+            type = eBinaryTypeUserAllImageInfos;
+            typestr = "userland dyld_all_image_infos";
+            break;
           }
           LLDB_LOGF(log,
                     "LC_NOTE 'main bin spec' found, version %d type %d "