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arch,base: Separate the idea of a memory image and object file.

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A memory image can be described by an object file, but an object file
is more than a memory image. Also, it makes sense to manipulate a
memory image to, for instance, change how it's loaded into memory. That
takes on larger implications (relocations, the entry point, symbols,
etc.) when talking about the whole object file, and also modifies
aspects which may not need to change. For instance if an image needs
to be loaded into memory at addresses different from what's in the
object file, but other things like symbols need to stay unmodified.

Change-Id: Ia360405ffb2c1c48e0cc201ac0a0764357996a54
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21466
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>
This commit is contained in:
Gabe Black
2019-10-01 21:15:06 -07:00
parent 211869ea95
commit 6ee86bf497
34 changed files with 424 additions and 338 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
src/sim/process.cc
View File

@@ -129,6 +129,8 @@ Process::Process(ProcessParams *params, EmulationPageTable *pTable,
exitGroup = new bool();
sigchld = new bool();
image = objFile->buildImage();
if (!debugSymbolTable) {
debugSymbolTable = new SymbolTable();
if (!objFile->loadGlobalSymbols(debugSymbolTable) ||
@@ -270,6 +272,16 @@ Process::revokeThreadContext(int context_id)
warn("Unable to find thread context to revoke");
}
void
Process::init()
{
// Patch the ld_bias for dynamic executables.
updateBias();
if (objFile->getInterpreter())
interpImage = objFile->getInterpreter()->buildImage();
}
void
Process::initState()
{
@@ -283,6 +295,10 @@ Process::initState()
tc->activate();
pTable->initState();
// load object file into target memory
image.write(initVirtMem);
interpImage.write(initVirtMem);
}
DrainState

4
src/sim/process.hh
View File

@@ -41,6 +41,7 @@
#include <vector>
#include "arch/registers.hh"
#include "base/loader/memory_image.hh"
#include "base/statistics.hh"
#include "base/types.hh"
#include "config/the_isa.hh"
@@ -69,6 +70,7 @@ class Process : public SimObject
void serialize(CheckpointOut &cp) const override;
void unserialize(CheckpointIn &cp) override;
void init() override;
void initState() override;
DrainState drain() override;
@@ -182,6 +184,8 @@ class Process : public SimObject
SETranslatingPortProxy initVirtMem; // memory proxy for initial image load
ObjectFile *objFile;
MemoryImage image;
MemoryImage interpImage;
std::vector<std::string> argv;
std::vector<std::string> envp;
std::string executable;

17
src/sim/syscall_emul.hh
View File

@@ -1886,17 +1886,14 @@ mmapImpl(SyscallDesc *desc, int num, ThreadContext *tc, bool is_mmap2)
// executing inside the loader by checking the program counter value.
// XXX: with multiprogrammed workloads or multi-node configurations,
// this will not work since there is a single global symbol table.
ObjectFile *interpreter = p->getInterpreter();
if (interpreter) {
if (interpreter->contains(tc->pcState().instAddr())) {
std::shared_ptr<FDEntry> fdep = (*p->fds)[tgt_fd];
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>(fdep);
ObjectFile *lib = createObjectFile(ffdp->getFileName());
if (p->interpImage.contains(tc->pcState().instAddr())) {
std::shared_ptr<FDEntry> fdep = (*p->fds)[tgt_fd];
auto ffdp = std::dynamic_pointer_cast<FileFDEntry>(fdep);
ObjectFile *lib = createObjectFile(ffdp->getFileName());
if (lib) {
lib->loadAllSymbols(debugSymbolTable,
lib->minSegmentAddr(), start);
}
if (lib) {
lib->loadAllSymbols(debugSymbolTable,
lib->buildImage().minAddr(), start);
}
}

34
src/sim/system.cc
View File

@@ -152,16 +152,16 @@ System::System(Params *p)
} else {
// Get the kernel code
kernel = createObjectFile(params()->kernel);
kernel->setLoadOffset(loadAddrOffset);
kernel->setLoadMask(loadAddrMask);
inform("kernel located at: %s", params()->kernel);
if (kernel == NULL)
fatal("Could not load kernel file %s", params()->kernel);
kernelImage = kernel->buildImage();
// setup entry points
kernelStart = kernel->minSegmentAddr();
kernelEnd = kernel->maxSegmentAddr();
kernelStart = kernelImage.minAddr();
kernelEnd = kernelImage.maxAddr();
kernelEntry = kernel->entryPoint();
// If load_addr_mask is set to 0x0, then auto-calculate
@@ -170,9 +170,12 @@ System::System(Params *p)
if (loadAddrMask == 0) {
Addr shift_amt = findMsbSet(kernelEnd - kernelStart) + 1;
loadAddrMask = ((Addr)1 << shift_amt) - 1;
kernel->setLoadMask(loadAddrMask);
}
kernelImage.move([this](Addr a) {
return (a & loadAddrMask) + loadAddrOffset;
});
// load symbols
if (!kernel->loadGlobalSymbols(kernelSymtab))
fatal("could not load kernel symbols\n");
@@ -195,8 +198,6 @@ System::System(Params *p)
ObjectFile *obj = createObjectFile(obj_name);
fatal_if(!obj, "Failed to additional kernel object '%s'.\n",
obj_name);
obj->setLoadOffset(loadAddrOffset);
obj->setLoadMask(loadAddrMask);
kernelExtras.push_back(obj);
}
}
@@ -316,25 +317,24 @@ System::initState()
/**
* Load the kernel code into memory
*/
auto mapper = [this](Addr a) {
return (a & loadAddrMask) + loadAddrOffset;
};
if (params()->kernel != "") {
if (params()->kernel_addr_check) {
// Validate kernel mapping before loading binary
if (!(isMemAddr((kernelStart & loadAddrMask) +
loadAddrOffset) &&
isMemAddr((kernelEnd & loadAddrMask) +
loadAddrOffset))) {
if (!isMemAddr(mapper(kernelStart)) ||
!isMemAddr(mapper(kernelEnd))) {
fatal("Kernel is mapped to invalid location (not memory). "
"kernelStart 0x(%x) - kernelEnd 0x(%x) %#x:%#x\n",
kernelStart,
kernelEnd, (kernelStart & loadAddrMask) +
loadAddrOffset,
(kernelEnd & loadAddrMask) + loadAddrOffset);
kernelStart, kernelEnd,
mapper(kernelStart), mapper(kernelEnd));
}
}
// Load program sections into memory
kernel->loadSegments(physProxy);
kernelImage.write(physProxy);
for (const auto &extra_kernel : kernelExtras)
extra_kernel->loadSegments(physProxy);
extra_kernel->buildImage().move(mapper).write(physProxy);
DPRINTF(Loader, "Kernel start = %#x\n", kernelStart);
DPRINTF(Loader, "Kernel end = %#x\n", kernelEnd);

2
src/sim/system.hh
View File

@@ -53,6 +53,7 @@
#include <vector>
#include "arch/isa_traits.hh"
#include "base/loader/memory_image.hh"
#include "base/loader/symtab.hh"
#include "base/statistics.hh"
#include "config/the_isa.hh"
@@ -224,6 +225,7 @@ class System : public SimObject
/** Object pointer for the kernel code */
ObjectFile *kernel;
MemoryImage kernelImage;
/** Additional object files */
std::vector<ObjectFile *> kernelExtras;