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Add/fix support for i386 elf core files 

Summary:
There were places in the code, assuming(hardcoding) offsets
and types that were only valid for the x86_64 elf core file format.

The NT_PRSTATUS and NT_PRPSINFO structures are with the 64 bit layout.
I have reused them and parse i386 files manually, and fill them in the
same struct.

Also added some error handling during parsing that checks if the
available bytes in the buffer are enough to fill the structures.

The i386 core file test case now passes.

For reference on the structures layout, I generally used the
source of binutils (bfd, readelf)

Bug: https://llvm.org/bugs/show_bug.cgi?id=26947

Reviewers: labath

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D22917

llvm-svn: 277140
This commit is contained in:
Dimitar Vlahovski 2016-07-29 13:18:09 +00:00
parent e768c4b858
commit 023dd64f25
6 changed files with 158 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
lldb/packages/Python/lldbsuite/test/functionalities/postmortem/linux-core/TestLinuxCore.py
View File

@ -25,7 +25,6 @@ class LinuxCoreTestCase(TestBase):
_x86_64_regions = 5
_s390x_regions = 2
@skipIf(bugnumber="llvm.org/pr26947")
def test_i386(self):
"""Test that lldb can read the process information from an i386 linux core file."""
self.do_test("i386", self._i386_pid, self._i386_regions)

20
lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
View File

@ -1479,7 +1479,7 @@ ObjectFileELF::RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, l
else if (note.n_name == LLDB_NT_OWNER_CORE)
{
// Parse the NT_FILE to look for stuff in paths to shared libraries
// As the contents look like:
// As the contents look like this in a 64 bit ELF core file:
// count = 0x000000000000000a (10)
// page_size = 0x0000000000001000 (4096)
// Index start end file_ofs path
@ -1494,14 +1494,24 @@ ObjectFileELF::RefineModuleDetailsFromNote (lldb_private::DataExtractor &data, l
// [ 7] 0x00007fa79cdb2000 0x00007fa79cdd5000 0x0000000000000000 /lib/x86_64-linux-gnu/ld-2.19.so
// [ 8] 0x00007fa79cfd4000 0x00007fa79cfd5000 0x0000000000000022 /lib/x86_64-linux-gnu/ld-2.19.so
// [ 9] 0x00007fa79cfd5000 0x00007fa79cfd6000 0x0000000000000023 /lib/x86_64-linux-gnu/ld-2.19.so
// In the 32 bit ELFs the count, page_size, start, end, file_ofs are uint32_t
// For reference: see readelf source code (in binutils).
if (note.n_type == NT_FILE)
{
uint64_t count = data.GetU64(&offset);
offset += 8 + 3*8*count; // Skip page size and all start/end/file_ofs
uint64_t count = data.GetAddress(&offset);
const char *cstr;
data.GetAddress(&offset); // Skip page size
offset += count * 3 * data.GetAddressByteSize(); // Skip all start/end/file_ofs
for (size_t i=0; i<count; ++i)
{
llvm::StringRef path(data.GetCStr(&offset));
if (path.startswith("/lib/x86_64-linux-gnu"))
cstr = data.GetCStr(&offset);
if(cstr == nullptr)
{
error.SetErrorStringWithFormat("ObjectFileELF::%s trying to read at an offset after the end (GetCStr returned nullptr)", __FUNCTION__);
return error;
}
llvm::StringRef path(cstr);
if (path.startswith("/lib/x86_64-linux-gnu") || path.startswith("/lib/i386-linux-gnu"))
{
arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
break;

20
lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp
View File

@ -223,8 +223,11 @@ ProcessElfCore::DoLoadCore ()
// Parse thread contexts and auxv structure
if (header->p_type == llvm::ELF::PT_NOTE)
ParseThreadContextsFromNoteSegment(header, data);
{
error = ParseThreadContextsFromNoteSegment(header, data);
if (error.Fail())
return error;
}
// PT_LOAD segments contains address map
if (header->p_type == llvm::ELF::PT_LOAD)
{
@ -533,7 +536,7 @@ ParseFreeBSDThrMisc(ThreadData &thread_data, DataExtractor &data)
/// new thread when it finds NT_PRSTATUS or NT_PRPSINFO NOTE entry.
/// For case (b) there may be either one NT_PRPSINFO per thread, or a single
/// one that applies to all threads (depending on the platform type).
void
Error
ProcessElfCore::ParseThreadContextsFromNoteSegment(const elf::ELFProgramHeader *segment_header,
DataExtractor segment_data)
{
@ -549,6 +552,7 @@ ProcessElfCore::ParseThreadContextsFromNoteSegment(const elf::ELFProgramHeader *
ELFLinuxPrStatus prstatus;
size_t header_size;
size_t len;
Error error;
// Loop through the NOTE entires in the segment
while (offset < segment_header->p_filesz)
@ -610,7 +614,9 @@ ProcessElfCore::ParseThreadContextsFromNoteSegment(const elf::ELFProgramHeader *
{
case NT_PRSTATUS:
have_prstatus = true;
prstatus.Parse(note_data, arch);
error = prstatus.Parse(note_data, arch);
if (error.Fail())
return error;
thread_data->signo = prstatus.pr_cursig;
thread_data->tid = prstatus.pr_pid;
header_size = ELFLinuxPrStatus::GetSize(arch);
@ -622,7 +628,9 @@ ProcessElfCore::ParseThreadContextsFromNoteSegment(const elf::ELFProgramHeader *
break;
case NT_PRPSINFO:
have_prpsinfo = true;
prpsinfo.Parse(note_data, arch);
error = prpsinfo.Parse(note_data, arch);
if (error.Fail())
return error;
thread_data->name = prpsinfo.pr_fname;
SetID(prpsinfo.pr_pid);
break;
@ -663,6 +671,8 @@ ProcessElfCore::ParseThreadContextsFromNoteSegment(const elf::ELFProgramHeader *
{
m_thread_data.push_back(*thread_data);
}
return error;
}
uint32_t

6
lldb/source/Plugins/Process/elf-core/ProcessElfCore.h
View File

@ -166,9 +166,9 @@ private:
std::vector<NT_FILE_Entry> m_nt_file_entries;
// Parse thread(s) data structures(prstatus, prpsinfo) from given NOTE segment
void
ParseThreadContextsFromNoteSegment (const elf::ELFProgramHeader *segment_header,
lldb_private::DataExtractor segment_data);
lldb_private::Error
ParseThreadContextsFromNoteSegment(const elf::ELFProgramHeader *segment_header,
lldb_private::DataExtractor segment_data);
// Returns number of thread contexts stored in the core file
uint32_t

111
lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp
View File

@ -19,6 +19,7 @@
#include "Plugins/Process/Utility/RegisterContextLinux_arm.h"
#include "Plugins/Process/Utility/RegisterContextLinux_arm64.h"
#include "Plugins/Process/Utility/RegisterContextLinux_s390x.h"
#include "Plugins/Process/Utility/RegisterContextLinux_i386.h"
#include "Plugins/Process/Utility/RegisterContextLinux_x86_64.h"
#include "Plugins/Process/Utility/RegisterContextFreeBSD_arm.h"
#include "Plugins/Process/Utility/RegisterContextFreeBSD_arm64.h"
@ -144,6 +145,9 @@ ThreadElfCore::CreateRegisterContextForFrame (StackFrame *frame)
case llvm::Triple::systemz:
reg_interface = new RegisterContextLinux_s390x(arch);
break;
case llvm::Triple::x86:
reg_interface = new RegisterContextLinux_i386(arch);
break;
case llvm::Triple::x86_64:
reg_interface = new RegisterContextLinux_x86_64(arch);
break;
@ -219,20 +223,65 @@ ELFLinuxPrStatus::ELFLinuxPrStatus()
memset(this, 0, sizeof(ELFLinuxPrStatus));
}
bool
Error
ELFLinuxPrStatus::Parse(DataExtractor &data, ArchSpec &arch)
{
Error error;
ByteOrder byteorder = data.GetByteOrder();
size_t len;
if (GetSize(arch) > data.GetByteSize())
{
error.SetErrorStringWithFormat("NT_PRSTATUS size should be %lu, but the remaining bytes are: %lu",
GetSize(arch), data.GetByteSize());
return error;
}
switch(arch.GetCore())
{
case ArchSpec::eCore_s390x_generic:
case ArchSpec::eCore_x86_64_x86_64:
len = data.ExtractBytes(0, sizeof(ELFLinuxPrStatus), byteorder, this);
return len == sizeof(ELFLinuxPrStatus);
data.ExtractBytes(0, sizeof(ELFLinuxPrStatus), byteorder, this);
break;
case ArchSpec::eCore_x86_32_i386:
case ArchSpec::eCore_x86_32_i486:
{
// Parsing from a 32 bit ELF core file, and populating/reusing the structure
// properly, because the struct is for the 64 bit version
offset_t offset = 0;
si_signo = data.GetU32(&offset);
si_code = data.GetU32(&offset);
si_errno = data.GetU32(&offset);
pr_cursig = data.GetU16(&offset);
offset += 2; // pad
pr_sigpend = data.GetU32(&offset);
pr_sighold = data.GetU32(&offset);
pr_pid = data.GetU32(&offset);
pr_ppid = data.GetU32(&offset);
pr_pgrp = data.GetU32(&offset);
pr_sid = data.GetU32(&offset);
pr_utime.tv_sec = data.GetU32(&offset);
pr_utime.tv_usec = data.GetU32(&offset);
pr_stime.tv_sec = data.GetU32(&offset);
pr_stime.tv_usec = data.GetU32(&offset);
pr_cutime.tv_sec = data.GetU32(&offset);
pr_cutime.tv_usec = data.GetU32(&offset);
pr_cstime.tv_sec = data.GetU32(&offset);
pr_cstime.tv_usec = data.GetU32(&offset);
break;
}
default:
return false;
error.SetErrorStringWithFormat("ELFLinuxPrStatus::%s Unknown architecture", __FUNCTION__);
break;
}
return error;
}
//----------------------------------------------------------------
@ -243,19 +292,61 @@ ELFLinuxPrPsInfo::ELFLinuxPrPsInfo()
memset(this, 0, sizeof(ELFLinuxPrPsInfo));
}
bool
Error
ELFLinuxPrPsInfo::Parse(DataExtractor &data, ArchSpec &arch)
{
Error error;
ByteOrder byteorder = data.GetByteOrder();
size_t len;
if (GetSize(arch) > data.GetByteSize())
{
error.SetErrorStringWithFormat("NT_PRPSINFO size should be %lu, but the remaining bytes are: %lu",
GetSize(arch), data.GetByteSize());
return error;
}
switch(arch.GetCore())
{
case ArchSpec::eCore_s390x_generic:
case ArchSpec::eCore_x86_64_x86_64:
len = data.ExtractBytes(0, sizeof(ELFLinuxPrPsInfo), byteorder, this);
return len == sizeof(ELFLinuxPrPsInfo);
data.ExtractBytes(0, sizeof(ELFLinuxPrPsInfo), byteorder, this);
break;
case ArchSpec::eCore_x86_32_i386:
case ArchSpec::eCore_x86_32_i486:
{
// Parsing from a 32 bit ELF core file, and populating/reusing the structure
// properly, because the struct is for the 64 bit version
size_t size = 0;
offset_t offset = 0;
pr_state = data.GetU8(&offset);
pr_sname = data.GetU8(&offset);
pr_zomb = data.GetU8(&offset);
pr_nice = data.GetU8(&offset);
pr_flag = data.GetU32(&offset);
pr_uid = data.GetU16(&offset);
pr_gid = data.GetU16(&offset);
pr_pid = data.GetU32(&offset);
pr_ppid = data.GetU32(&offset);
pr_pgrp = data.GetU32(&offset);
pr_sid = data.GetU32(&offset);
size = 16;
data.ExtractBytes(offset, size, byteorder, pr_fname);
offset += size;
size = 80;
data.ExtractBytes(offset, size, byteorder, pr_psargs);
offset += size;
break;
}
default:
return false;
error.SetErrorStringWithFormat("ELFLinuxPrPsInfo::%s Unknown architecture", __FUNCTION__);
break;
}
return error;
}

28
lldb/source/Plugins/Process/elf-core/ThreadElfCore.h
View File

@ -26,8 +26,10 @@ struct compat_timeval
};
// PRSTATUS structure's size differs based on architecture.
// Currently parsing done only for x86-64 architecture by
// simply reading data from the buffer.
// This is the layout in the x86-64 arch.
// In the i386 case we parse it manually and fill it again
// in the same structure
// The gp registers are also a part of this struct, but they are handled separately
#undef si_signo
#undef si_code
@ -56,9 +58,13 @@ struct ELFLinuxPrStatus
ELFLinuxPrStatus();
bool
lldb_private::Error
Parse(lldb_private::DataExtractor &data, lldb_private::ArchSpec &arch);
// Return the bytesize of the structure
// 64 bit - just sizeof
// 32 bit - hardcoded because we are reusing the struct, but some of the members are smaller -
// so the layout is not the same
static size_t
GetSize(lldb_private::ArchSpec &arch)
{
@ -67,6 +73,9 @@ struct ELFLinuxPrStatus
case lldb_private::ArchSpec::eCore_s390x_generic:
case lldb_private::ArchSpec::eCore_x86_64_x86_64:
return sizeof(ELFLinuxPrStatus);
case lldb_private::ArchSpec::eCore_x86_32_i386:
case lldb_private::ArchSpec::eCore_x86_32_i486:
return 72;
default:
return 0;
}
@ -75,6 +84,10 @@ struct ELFLinuxPrStatus
static_assert(sizeof(ELFLinuxPrStatus) == 112, "sizeof ELFLinuxPrStatus is not correct!");
// PRPSINFO structure's size differs based on architecture.
// This is the layout in the x86-64 arch case.
// In the i386 case we parse it manually and fill it again
// in the same structure
struct ELFLinuxPrPsInfo
{
char pr_state;
@ -93,9 +106,13 @@ struct ELFLinuxPrPsInfo
ELFLinuxPrPsInfo();
bool
lldb_private::Error
Parse(lldb_private::DataExtractor &data, lldb_private::ArchSpec &arch);
// Return the bytesize of the structure
// 64 bit - just sizeof
// 32 bit - hardcoded because we are reusing the struct, but some of the members are smaller -
// so the layout is not the same
static size_t
GetSize(lldb_private::ArchSpec &arch)
{
@ -104,6 +121,9 @@ struct ELFLinuxPrPsInfo
case lldb_private::ArchSpec::eCore_s390x_generic:
case lldb_private::ArchSpec::eCore_x86_64_x86_64:
return sizeof(ELFLinuxPrPsInfo);
case lldb_private::ArchSpec::eCore_x86_32_i386:
case lldb_private::ArchSpec::eCore_x86_32_i486:
return 124;
default:
return 0;
}