[lldb-dev] LLDB does not respect platform sysroot when loading core on Linux
Pavel Labath via lldb-dev
lldb-dev at lists.llvm.org
Mon Jul 23 02:42:24 PDT 2018
Instead of "image search-paths add" you should be able to do a
"settings append target.exec-search-paths /your/sysroot". That one
should not require a running target or anything like that.
However, I agree that it would be nice for the platform sysroot to
work out of the box. Particularly, as we can then use it to do other
nice things (e.g. prevent matching of files in the main filesystem, so
we can avoid the ld-linux-x86-64.so.2 problem you encountered).
For the patch, can you create a review on the LLVM phabricator
<https://reviews.llvm.org/differential>? We can discuss the approach
there.
On Fri, 20 Jul 2018 at 23:55, Eugene Birukov via lldb-dev
<lldb-dev at lists.llvm.org> wrote:
>
> I have a small fix – pass platform sysroot to ModuleList::GetSharedModule. The fix works for me.
>
>
>
> What should I do to get it reviewed?
>
>
>
> Thanks,
>
> Eugene
>
>
>
> diff --git a/include/lldb/Core/ModuleList.h b/include/lldb/Core/ModuleList.h
>
> index 4b637c9..3214291 100644
>
> --- a/include/lldb/Core/ModuleList.h
>
> +++ b/include/lldb/Core/ModuleList.h
>
> @@ -541,7 +541,8 @@ public:
>
> const FileSpecList *module_search_paths_ptr,
>
> lldb::ModuleSP *old_module_sp_ptr,
>
> bool *did_create_ptr,
>
> - bool always_create = false);
>
> + bool always_create = false,
>
> + const char* sysroot = nullptr);
>
>
>
> static bool RemoveSharedModule(lldb::ModuleSP &module_sp);
>
>
>
> diff --git a/source/Core/ModuleList.cpp b/source/Core/ModuleList.cpp
>
> index 3970052..f2db3bb 100644
>
> --- a/source/Core/ModuleList.cpp
>
> +++ b/source/Core/ModuleList.cpp
>
> @@ -707,7 +707,11 @@ Status ModuleList::GetSharedModule(const ModuleSpec &module_spec,
>
> ModuleSP &module_sp,
>
> const FileSpecList *module_search_paths_ptr,
>
> ModuleSP *old_module_sp_ptr,
>
> - bool *did_create_ptr, bool always_create) {
>
> + bool *did_create_ptr, bool always_create,
>
> + const char* sysroot) {
>
> + // Make sure no one else can try and get or create a module while this
>
> + // function is actively working on it by doing an extra lock on the
>
> + // global mutex list.
>
> ModuleList &shared_module_list = GetSharedModuleList();
>
> std::lock_guard<std::recursive_mutex> guard(
>
> shared_module_list.m_modules_mutex);
>
> @@ -726,9 +730,6 @@ Status ModuleList::GetSharedModule(const ModuleSpec &module_spec,
>
> const FileSpec &module_file_spec = module_spec.GetFileSpec();
>
> const ArchSpec &arch = module_spec.GetArchitecture();
>
>
>
> - // Make sure no one else can try and get or create a module while this
>
> - // function is actively working on it by doing an extra lock on the
>
> - // global mutex list.
>
> if (!always_create) {
>
> ModuleList matching_module_list;
>
> const size_t num_matching_modules =
>
> @@ -762,7 +763,11 @@ Status ModuleList::GetSharedModule(const ModuleSpec &module_spec,
>
> if (module_sp)
>
> return error;
>
>
>
> - module_sp.reset(new Module(module_spec));
>
> + auto resolved_module_spec(module_spec);
>
> + if (sysroot != nullptr)
>
> + resolved_module_spec.GetFileSpec().PrependPathComponent(sysroot);
>
> +
>
> + module_sp.reset(new Module(resolved_module_spec));
>
> // Make sure there are a module and an object file since we can specify
>
> // a valid file path with an architecture that might not be in that file.
>
> // By getting the object file we can guarantee that the architecture matches
>
> diff --git a/source/Target/Platform.cpp b/source/Target/Platform.cpp
>
> index 5d60bb7..19161cc 100644
>
> --- a/source/Target/Platform.cpp
>
> +++ b/source/Target/Platform.cpp
>
> @@ -225,13 +225,14 @@ Status Platform::GetSharedModule(const ModuleSpec &module_spec,
>
> if (IsHost())
>
> return ModuleList::GetSharedModule(
>
> module_spec, module_sp, module_search_paths_ptr, old_module_sp_ptr,
>
> - did_create_ptr, false);
>
> + did_create_ptr, false, m_sdk_sysroot.AsCString());
>
>
>
> return GetRemoteSharedModule(module_spec, process, module_sp,
>
> [&](const ModuleSpec &spec) {
>
> Status error = ModuleList::GetSharedModule(
>
> spec, module_sp, module_search_paths_ptr,
>
> - old_module_sp_ptr, did_create_ptr, false);
>
> + old_module_sp_ptr, did_create_ptr, false,
>
> + m_sdk_sysroot.AsCString());
>
> if (error.Success() && module_sp)
>
> module_sp->SetPlatformFileSpec(
>
> spec.GetFileSpec());
>
>
>
> From: lldb-dev <lldb-dev-bounces at lists.llvm.org> On Behalf Of Eugene Birukov via lldb-dev
> Sent: Friday, July 20, 2018 12:21 PM
> To: Ted Woodward <ted.woodward at codeaurora.org>; lldb-dev at lists.llvm.org
> Subject: Re: [lldb-dev] LLDB does not respect platform sysroot when loading core on Linux
>
>
>
> Shouldn’t platform trick work?
> This doesn’t work too. “image” command is rejected if I don’t have the target created. But if I issue it after I got target, the module list gets practically empty. Only the modules I have exactly matching between my machine and the target are left.
>
>
>
> Another problem: ld-linux-x86-64.so.2 has matched from my machine, but this is actually a different file.
>
>
>
> (lldb) image search-paths add / /tmp/debugcore.3WyoW4/lib2/
>
> error: invalid target
>
>
>
> (lldb) target create -c core bin/executable
>
> Core file … (x86_64) was loaded.
>
> (lldb) target mod list
>
> [ 0] EB1EC4C1-8C92-1BBC-5EEC-98AAD9006691-2E1FE735 /tmp/debugcore.3WyoW4/bin/executable
>
> [ 1] BBCFB8B3-D0D8-9B97-9231-645196845E00-CB55E7D0 /opt/xxxxx/bin/../lib/libc++.so.1
>
> [ 2] AF1A7705-DAC0-8661-7411-8DEFE8281C64-AED273A9 /opt/xxxxx/bin/../lib/libc++abi.so.1
>
> [ 3] 5D7B6259-5522-75A3-C17B-D4C3FD05F5A6-BF40CAA5 /lib64/ld-linux-x86-64.so.2
>
> [ 4] F40CF56C-9984-4493-6E56-9E905018C61A-446E19F3 0x00007ffd3f9d2000 [vdso] (0x00007ffd3f9d2000)
>
> [ 5] 402F8E9C-0000-0000-0000-000000000000 0x00007f0e8094e000 /lib64/libpthread.so.0 (0x00007f0e8094e000)
>
> [ 6] C36E0F49-0000-0000-0000-000000000000 0x00007f0e80746000 /lib64/librt.so.1 (0x00007f0e80746000)
>
> [ 7] DA7C854B-0000-0000-0000-000000000000 0x00007f0e80542000 /lib64/libdl.so.2 (0x00007f0e80542000)
>
> [ 8] 9EFAADB9-0000-0000-0000-000000000000 0x00007f0e7feb2000 /lib64/libcrypto.so.10 (0x00007f0e7feb2000)
>
> [ 9] 1B54BC7F-0000-0000-0000-000000000000 0x00007f0e7fc44000 /lib64/libssl.so.10 (0x00007f0e7fc44000)
>
> [ 10] 0E999CDE-0000-0000-0000-000000000000 0x00007f0e7fa38000 /lib64/libnuma.so.1 (0x00007f0e7fa38000)
>
> [ 11] 51C7A74C-0000-0000-0000-000000000000 0x00007f0e7f7ea000 /lib64/libgssapi_krb5.so.2 (0x00007f0e7f7ea000)
>
> [ 12] D74EFC55-0000-0000-0000-000000000000 0x00007f0e7f503000 /lib64/libkrb5.so.3 (0x00007f0e7f503000)
>
> [ 13] 57A9AB75-0000-0000-0000-000000000000 0x00007f0e7f2d1000 /lib64/libk5crypto.so.3 (0x00007f0e7f2d1000)
>
> [ 14] 93F50DD9-0000-0000-0000-000000000000 0x00007f0e7f0cd000 /lib64/libcom_err.so.2 (0x00007f0e7f0cd000)
>
> [ 15] 04DA7429-0000-0000-0000-000000000000 0x00007f0e7ee8f000 /lib64/libblkid.so.1 (0x00007f0e7ee8f000)
>
> [ 16] 0D4800F4-0000-0000-0000-000000000000 0x00007f0e7ec8a000 /lib64/libsss_nss_idmap.so.0 (0x00007f0e7ec8a000)
>
> [ 17] 07CAC506-0000-0000-0000-000000000000 0x00007f0e7ea85000 /lib64/libuuid.so.1 (0x00007f0e7ea85000)
>
> [ 18] A69E7F20-0000-0000-0000-000000000000 0x00007f0e7e537000 /lib64/libm.so.6 (0x00007f0e7e537000)
>
> [ 19] 9FAE7CD0-0000-0000-0000-000000000000 0x00007f0e7e321000 /lib64/libgcc_s.so.1 (0x00007f0e7e321000)
>
> [ 20] 02E59CD0-0000-0000-0000-000000000000 0x00007f0e7df60000 /lib64/libc.so.6 (0x00007f0e7df60000)
>
> [ 21] 9FCA7001-0000-0000-0000-000000000000 0x00007f0e7dc58000 /lib64/libstdc++.so.6 (0x00007f0e7dc58000)
>
> [ 22] EADDCF0A-0000-0000-0000-000000000000 0x00007f0e7da42000 /lib64/libz.so.1 (0x00007f0e7da42000)
>
> [ 23] 4158BE15-0000-0000-0000-000000000000 0x00007f0e7d833000 /lib64/libkrb5support.so.0 (0x00007f0e7d833000)
>
> [ 24] 9213C8BE-0000-0000-0000-000000000000 0x00007f0e7d62f000 /lib64/libkeyutils.so.1 (0x00007f0e7d62f000)
>
> [ 25] DA713559-0000-0000-0000-000000000000 0x00007f0e7d415000 /lib64/libresolv.so.2 (0x00007f0e7d415000)
>
> [ 26] 7EC8B5FA-0000-0000-0000-000000000000 0x00007f0e7d1ee000 /lib64/libselinux.so.1 (0x00007f0e7d1ee000)
>
> [ 27] B618A715-0000-0000-0000-000000000000 0x00007f0e7cf8d000 /lib64/libpcre.so.1 (0x00007f0e7cf8d000)
>
> [ 28] 7BC742F6-EC7C-B8E9-3251-08C749F25E46-D76FE69D /opt/xxxxx/bin/../lib/libunwind.so.8
>
> [ 29] A3A6D23F-0000-0000-0000-000000000000 0x00007f0e75e24000 /lib64/liblzma.so.5 (0x00007f0e75e24000)
>
> [ 30] 682FA1FE-0000-0000-0000-000000000000 0x00007f0e2f531000 /usr/lib64/gssproxy/proxymech.so (0x00007f0e2f531000)
>
> [ 31] DA479E71-0000-0000-0000-000000000000 0x00007f0e2f305000 /lib64/libgssrpc.so.4 (0x00007f0e2f305000)
>
> [ 32] D10ACB70-0000-0000-0000-000000000000 0x00007f0e2b9ef000 /lib64/libnss_files.so.2 (0x00007f0e2b9ef000)
>
> [ 33] 8A5852DC-0000-0000-0000-000000000000 0x00007f0e2b7e9000 /lib64/libnss_dns.so.2 (0x00007f0e2b7e9000)
>
> [ 34] A19B4645-0000-0000-0000-000000000000 0x00007f0e2b733000 /lib64/libnss_myhostname.so.2 (0x00007f0e2b733000)
>
> [ 35] CB72796B-0000-0000-0000-000000000000 0x00007f0e2b52e000 /lib64/libcap.so.2 (0x00007f0e2b52e000)
>
> [ 36] 312FFEED-0000-0000-0000-000000000000 0x00007f0e2b2e6000 /lib64/libdw.so.1 (0x00007f0e2b2e6000)
>
> [ 37] 1B32E461-0000-0000-0000-000000000000 0x00007f0e2b0e1000 /lib64/libattr.so.1 (0x00007f0e2b0e1000)
>
> [ 38] 280E50A8-0000-0000-0000-000000000000 0x00007f0e2aec9000 /lib64/libelf.so.1 (0x00007f0e2aec9000)
>
> [ 39] FFB3D20E-0000-0000-0000-000000000000 0x00007f0e2acb9000 /lib64/libbz2.so.1 (0x00007f0e2acb9000)
>
> (lldb) image search-paths add / /tmp/debugcore.3WyoW4/lib2/
>
> (lldb) target mod list
>
> [ 0] EB1EC4C1-8C92-1BBC-5EEC-98AAD9006691-2E1FE735 /tmp/debugcore.3WyoW4/bin/executable
>
> [ 1] BBCFB8B3-D0D8-9B97-9231-645196845E00-CB55E7D0 /opt/xxxxx/bin/../lib/libc++.so.1
>
> [ 2] AF1A7705-DAC0-8661-7411-8DEFE8281C64-AED273A9 /opt/xxxxx/bin/../lib/libc++abi.so.1
>
> [ 3] 5D7B6259-5522-75A3-C17B-D4C3FD05F5A6-BF40CAA5 /lib64/ld-linux-x86-64.so.2
>
> (lldb)
>
>
>
> Thanks,
>
> Eugene
>
>
>
> From: Ted Woodward <ted.woodward at codeaurora.org>
> Sent: Friday, July 20, 2018 12:01 PM
> To: Eugene Birukov <eugenebi at microsoft.com>; lldb-dev at lists.llvm.org
> Subject: RE: [lldb-dev] LLDB does not respect platform sysroot when loading core on Linux
>
>
>
> Instead of setting the sysroot, try the command
>
> image search-paths add / /path/to/remote/shared/libraries/
>
>
>
> That adds to the list that the dynamic loader uses to map shared object paths.
>
>
>
> It uses a simple text substitution, so in the above case,
>
> /usr/lib/libc.so
>
> Becomes
>
> /path/to/remote/shared/libraries/usr/lib/libc.so
>
>
>
> Matching up trailing slashes is critical, as I learned the hard way!
>
>
>
> Ted
>
>
>
> --
>
> Qualcomm Innovation Center, Inc.
>
> The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
>
>
>
> From: lldb-dev [mailto:lldb-dev-bounces at lists.llvm.org] On Behalf Of Eugene Birukov via lldb-dev
> Sent: Friday, July 20, 2018 1:13 PM
> To: lldb-dev at lists.llvm.org
> Subject: [lldb-dev] LLDB does not respect platform sysroot when loading core on Linux
>
>
>
> Hello,
>
>
>
> I would appreciate advise how to fix this correctly…
>
>
>
> I have a core dump from somebody’s RHEL Linux and I am trying to open it on my Ubuntu. I have all the shared libraries from the target sitting under my local directory. So, GDB happily opens the core after I issue “set sysroot /path/to/local/root”, but LLDB release_60 fails to do it.
>
>
>
> I follow instructions from Greg’s Clayton mail http://lists.llvm.org/pipermail/lldb-dev/2016-January/009236.html :
>
>
>
> (lldb) platform select --sysroot /path/to/remote/shared/libraries remote-linux
>
> (lldb) <load core>
>
>
>
> Under debugger, I see that LLDB successfully created Platform object with m_sdk_root set to my path and the Target uses it as its platform:
>
>
>
> (gdb) p target_sp->m_platform_sp->m_sdk_sysroot
>
> $42 = {
>
> m_string = 0x80e070 "/tmp/debugcore.3WyoW4/lib2"
>
> }
>
>
>
> But this value is not used when it comes to DynamicLoaderPOSIXDYLD::LoadAllCurrentModules.
>
> (gdb) bt
>
> #0 lldb_private::ModuleList::GetSharedModule (module_spec=..., module_sp=std::shared_ptr (empty) 0x0,
>
> module_search_paths_ptr=0x83ad60, old_module_sp_ptr=0x7fffffffbb50, did_create_ptr=0x7fffffffbb07,
>
> always_create=false) at /home/eugene/llvm/tools/lldb/source/Core/ModuleList.cpp:710
>
> #1 0x00007fffedc2d130 in lldb_private::Platform::<lambda(const lldb_private::ModuleSpec&)>::operator()(const lldb_private::ModuleSpec &) const (__closure=0x8581b0, spec=...)
>
> at /home/eugene/llvm/tools/lldb/source/Target/Platform.cpp:234
>
> #2 0x00007fffedc34ff2 in std::_Function_handler<lldb_private::Status(const lldb_private::ModuleSpec&), lldb_private::Platform::GetSharedModule(const lldb_private::ModuleSpec&, lldb_private::Process*, lldb::ModuleSP&, const lldb_private::FileSpecList*, lldb::ModuleSP*, bool*)::<lambda(const lldb_private::ModuleSpec&)> >::_M_invoke(const std::_Any_data &, const lldb_private::ModuleSpec &) (__functor=..., __args#0=...) at /usr/include/c++/5/functional:1857
>
> #3 0x00007fffedc37978 in std::function<lldb_private::Status (lldb_private::ModuleSpec const&)>::operator()(lldb_private::ModuleSpec const&) const (this=0x7fffffffba80, __args#0=...) at /usr/include/c++/5/functional:2267
>
> #4 0x00007fffedc3375a in lldb_private::Platform::GetRemoteSharedModule(lldb_private::ModuleSpec const&, lldb_private::Process*, std::shared_ptr<lldb_private::Module>&, std::function<lldb_private::Status (lldb_private::ModuleSpec const&)> const&, bool*) (this=0x839330, module_spec=..., process=0x84d310, module_sp=std::shared_ptr (empty) 0x0,
>
> module_resolver=..., did_create_ptr=0x7fffffffbb07)
>
> at /home/eugene/llvm/tools/lldb/source/Target/Platform.cpp:1628
>
> #5 0x00007fffedc2d2cd in lldb_private::Platform::GetSharedModule (this=0x839330, module_spec=...,
>
> process=0x84d310, module_sp=std::shared_ptr (empty) 0x0, module_search_paths_ptr=0x83ad60,
>
> old_module_sp_ptr=0x7fffffffbb50, did_create_ptr=0x7fffffffbb07)
>
> at /home/eugene/llvm/tools/lldb/source/Target/Platform.cpp:240
>
> #6 0x00007fffedc9957c in lldb_private::Target::GetSharedModule (this=0x846960, module_spec=..., error_ptr=0x0)
>
> at /home/eugene/llvm/tools/lldb/source/Target/Target.cpp:1952
>
> #7 0x00007fffef8e0d11 in lldb_private::DynamicLoader::LoadModuleAtAddress (this=0x9a0a70, file=...,
>
> link_map_addr=139700267943784, base_addr=139700263510016, base_addr_is_offset=true)
>
> at /home/eugene/llvm/tools/lldb/source/Core/DynamicLoader.cpp:171
>
> #8 0x00007fffedd8fb55 in DynamicLoaderPOSIXDYLD::LoadAllCurrentModules (this=0x9a0a70)
>
> at /home/eugene/llvm/tools/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp:537
>
> #9 0x00007fffedd8de52 in DynamicLoaderPOSIXDYLD::DidAttach (this=0x9a0a70)
>
> at /home/eugene/llvm/tools/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp:171
>
> #10 0x00007fffedc476d9 in lldb_private::Process::LoadCore (this=0x84d310)
>
> at /home/eugene/llvm/tools/lldb/source/Target/Process.cpp:2853
>
>
>
> I simply do not see any reference to sysroot in the GetSharedModule() code. What is there – it is only scanning module_search_paths_ptr looking for file. This would not work because the scan ignores the directory part of the module: it takes the next path from the list and appends the file name. What I need instead – take m_sdk_sysroot from Platform and append the full module – including directory – to it.
>
>
>
> Unfortunately, GetSharedModule() is a static method and does not have any clue what is current platform or current target. So, should I pass another argument down there with sysroot or what? I have correct platform object at frame 4.
>
>
>
> Thanks,
>
> Eugene
>
>
>
>
>
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