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Unified Diff: sandbox/linux/seccomp-bpf/codegen.cc

Issue 66723007: Make sandbox/linux/seccomp-bpf/ follow the style guide. (Closed) Base URL: svn://svn.chromium.org/chrome/trunk/src
Patch Set: (empty) rebase Created 7 years, 1 month ago
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Index: sandbox/linux/seccomp-bpf/codegen.cc
diff --git a/sandbox/linux/seccomp-bpf/codegen.cc b/sandbox/linux/seccomp-bpf/codegen.cc
index 17b5d846dc9765227470e55ea1eda9004ae31468..77df612110b75726072e98ae2fdb68063d210138 100644
--- a/sandbox/linux/seccomp-bpf/codegen.cc
+++ b/sandbox/linux/seccomp-bpf/codegen.cc
@@ -6,26 +6,25 @@
#include "sandbox/linux/seccomp-bpf/codegen.h"
-
namespace {
// Helper function for Traverse().
-void TraverseRecursively(std::set<playground2::Instruction *> *visited,
- playground2::Instruction *instruction) {
+void TraverseRecursively(std::set<playground2::Instruction*>* visited,
+ playground2::Instruction* instruction) {
if (visited->find(instruction) == visited->end()) {
visited->insert(instruction);
switch (BPF_CLASS(instruction->code)) {
- case BPF_JMP:
- if (BPF_OP(instruction->code) != BPF_JA) {
- TraverseRecursively(visited, instruction->jf_ptr);
- }
- TraverseRecursively(visited, instruction->jt_ptr);
- break;
- case BPF_RET:
- break;
- default:
- TraverseRecursively(visited, instruction->next);
- break;
+ case BPF_JMP:
+ if (BPF_OP(instruction->code) != BPF_JA) {
+ TraverseRecursively(visited, instruction->jf_ptr);
+ }
+ TraverseRecursively(visited, instruction->jt_ptr);
+ break;
+ case BPF_RET:
+ break;
+ default:
+ TraverseRecursively(visited, instruction->next);
+ break;
}
}
}
@@ -34,9 +33,7 @@ void TraverseRecursively(std::set<playground2::Instruction *> *visited,
namespace playground2 {
-CodeGen::CodeGen()
- : compiled_(false) {
-}
+CodeGen::CodeGen() : compiled_(false) {}
CodeGen::~CodeGen() {
for (Instructions::iterator iter = instructions_.begin();
@@ -58,108 +55,114 @@ void CodeGen::PrintProgram(const Sandbox::Program& program) {
int ip = (int)(iter - program.begin());
fprintf(stderr, "%3d) ", ip);
switch (BPF_CLASS(iter->code)) {
- case BPF_LD:
- if (iter->code == BPF_LD+BPF_W+BPF_ABS) {
- fprintf(stderr, "LOAD %d // ", (int)iter->k);
- if (iter->k == offsetof(struct arch_seccomp_data, nr)) {
- fprintf(stderr, "System call number\n");
- } else if (iter->k == offsetof(struct arch_seccomp_data, arch)) {
- fprintf(stderr, "Architecture\n");
- } else if (iter->k == offsetof(struct arch_seccomp_data,
- instruction_pointer)) {
- fprintf(stderr, "Instruction pointer (LSB)\n");
- } else if (iter->k == offsetof(struct arch_seccomp_data,
- instruction_pointer) + 4) {
- fprintf(stderr, "Instruction pointer (MSB)\n");
- } else if (iter->k >= offsetof(struct arch_seccomp_data, args) &&
- iter->k < offsetof(struct arch_seccomp_data, args)+48 &&
- (iter->k-offsetof(struct arch_seccomp_data, args))%4 == 0) {
- fprintf(stderr, "Argument %d (%cSB)\n",
- (int)(iter->k-offsetof(struct arch_seccomp_data, args))/8,
- (iter->k-offsetof(struct arch_seccomp_data,
- args))%8 ? 'M' : 'L');
+ case BPF_LD:
+ if (iter->code == BPF_LD + BPF_W + BPF_ABS) {
+ fprintf(stderr, "LOAD %d // ", (int)iter->k);
+ if (iter->k == offsetof(struct arch_seccomp_data, nr)) {
+ fprintf(stderr, "System call number\n");
+ } else if (iter->k == offsetof(struct arch_seccomp_data, arch)) {
+ fprintf(stderr, "Architecture\n");
+ } else if (iter->k ==
+ offsetof(struct arch_seccomp_data, instruction_pointer)) {
+ fprintf(stderr, "Instruction pointer (LSB)\n");
+ } else if (iter->k ==
+ offsetof(struct arch_seccomp_data, instruction_pointer) +
+ 4) {
+ fprintf(stderr, "Instruction pointer (MSB)\n");
+ } else if (iter->k >= offsetof(struct arch_seccomp_data, args) &&
+ iter->k < offsetof(struct arch_seccomp_data, args) + 48 &&
+ (iter->k - offsetof(struct arch_seccomp_data, args)) % 4 ==
+ 0) {
+ fprintf(
+ stderr,
+ "Argument %d (%cSB)\n",
+ (int)(iter->k - offsetof(struct arch_seccomp_data, args)) / 8,
+ (iter->k - offsetof(struct arch_seccomp_data, args)) % 8 ? 'M'
+ : 'L');
+ } else {
+ fprintf(stderr, "???\n");
+ }
+ } else {
+ fprintf(stderr, "LOAD ???\n");
+ }
+ break;
+ case BPF_JMP:
+ if (BPF_OP(iter->code) == BPF_JA) {
+ fprintf(stderr, "JMP %d\n", ip + iter->k + 1);
+ } else {
+ fprintf(stderr, "if A %s 0x%x; then JMP %d else JMP %d\n",
+ BPF_OP(iter->code) == BPF_JSET ? "&" :
+ BPF_OP(iter->code) == BPF_JEQ ? "==" :
+ BPF_OP(iter->code) == BPF_JGE ? ">=" :
+ BPF_OP(iter->code) == BPF_JGT ? ">" : "???",
+ (int)iter->k,
+ ip + iter->jt + 1, ip + iter->jf + 1);
+ }
+ break;
+ case BPF_RET:
+ fprintf(stderr, "RET 0x%x // ", iter->k);
+ if ((iter->k & SECCOMP_RET_ACTION) == SECCOMP_RET_TRAP) {
+ fprintf(stderr, "Trap #%d\n", iter->k & SECCOMP_RET_DATA);
+ } else if ((iter->k & SECCOMP_RET_ACTION) == SECCOMP_RET_ERRNO) {
+ fprintf(stderr, "errno = %d\n", iter->k & SECCOMP_RET_DATA);
+ } else if (iter->k == SECCOMP_RET_ALLOW) {
+ fprintf(stderr, "Allowed\n");
} else {
fprintf(stderr, "???\n");
}
- } else {
- fprintf(stderr, "LOAD ???\n");
- }
- break;
- case BPF_JMP:
- if (BPF_OP(iter->code) == BPF_JA) {
- fprintf(stderr, "JMP %d\n", ip + iter->k + 1);
- } else {
- fprintf(stderr, "if A %s 0x%x; then JMP %d else JMP %d\n",
- BPF_OP(iter->code) == BPF_JSET ? "&" :
- BPF_OP(iter->code) == BPF_JEQ ? "==" :
- BPF_OP(iter->code) == BPF_JGE ? ">=" :
- BPF_OP(iter->code) == BPF_JGT ? ">" : "???",
- (int)iter->k,
- ip + iter->jt + 1, ip + iter->jf + 1);
- }
- break;
- case BPF_RET:
- fprintf(stderr, "RET 0x%x // ", iter->k);
- if ((iter->k & SECCOMP_RET_ACTION) == SECCOMP_RET_TRAP) {
- fprintf(stderr, "Trap #%d\n", iter->k & SECCOMP_RET_DATA);
- } else if ((iter->k & SECCOMP_RET_ACTION) == SECCOMP_RET_ERRNO) {
- fprintf(stderr, "errno = %d\n", iter->k & SECCOMP_RET_DATA);
- } else if (iter->k == SECCOMP_RET_ALLOW) {
- fprintf(stderr, "Allowed\n");
- } else {
+ break;
+ case BPF_ALU:
+ fprintf(stderr, BPF_OP(iter->code) == BPF_NEG
+ ? "A := -A\n" : "A := A %s 0x%x\n",
+ BPF_OP(iter->code) == BPF_ADD ? "+" :
+ BPF_OP(iter->code) == BPF_SUB ? "-" :
+ BPF_OP(iter->code) == BPF_MUL ? "*" :
+ BPF_OP(iter->code) == BPF_DIV ? "/" :
+ BPF_OP(iter->code) == BPF_MOD ? "%" :
+ BPF_OP(iter->code) == BPF_OR ? "|" :
+ BPF_OP(iter->code) == BPF_XOR ? "^" :
+ BPF_OP(iter->code) == BPF_AND ? "&" :
+ BPF_OP(iter->code) == BPF_LSH ? "<<" :
+ BPF_OP(iter->code) == BPF_RSH ? ">>" : "???",
+ (int)iter->k);
+ break;
+ default:
fprintf(stderr, "???\n");
- }
- break;
- case BPF_ALU:
- fprintf(stderr, BPF_OP(iter->code) == BPF_NEG
- ? "A := -A\n" : "A := A %s 0x%x\n",
- BPF_OP(iter->code) == BPF_ADD ? "+" :
- BPF_OP(iter->code) == BPF_SUB ? "-" :
- BPF_OP(iter->code) == BPF_MUL ? "*" :
- BPF_OP(iter->code) == BPF_DIV ? "/" :
- BPF_OP(iter->code) == BPF_MOD ? "%" :
- BPF_OP(iter->code) == BPF_OR ? "|" :
- BPF_OP(iter->code) == BPF_XOR ? "^" :
- BPF_OP(iter->code) == BPF_AND ? "&" :
- BPF_OP(iter->code) == BPF_LSH ? "<<" :
- BPF_OP(iter->code) == BPF_RSH ? ">>" : "???",
- (int)iter->k);
- break;
- default:
- fprintf(stderr, "???\n");
- break;
+ break;
}
}
return;
}
-Instruction *CodeGen::MakeInstruction(uint16_t code, uint32_t k,
- Instruction *next) {
+Instruction* CodeGen::MakeInstruction(uint16_t code,
+ uint32_t k,
+ Instruction* next) {
// We can handle non-jumping instructions and "always" jumps. Both of
// them are followed by exactly one "next" instruction.
// We allow callers to defer specifying "next", but then they must call
// "joinInstructions" later.
if (BPF_CLASS(code) == BPF_JMP && BPF_OP(code) != BPF_JA) {
- SANDBOX_DIE("Must provide both \"true\" and \"false\" branch "
- "for a BPF_JMP");
+ SANDBOX_DIE(
+ "Must provide both \"true\" and \"false\" branch "
+ "for a BPF_JMP");
}
if (next && BPF_CLASS(code) == BPF_RET) {
SANDBOX_DIE("Cannot append instructions after a return statement");
}
if (BPF_CLASS(code) == BPF_JMP) {
// "Always" jumps use the "true" branch target, only.
- Instruction *insn = new Instruction(code, 0, next, NULL);
+ Instruction* insn = new Instruction(code, 0, next, NULL);
instructions_.push_back(insn);
return insn;
} else {
// Non-jumping instructions do not use any of the branch targets.
- Instruction *insn = new Instruction(code, k, next);
+ Instruction* insn = new Instruction(code, k, next);
instructions_.push_back(insn);
return insn;
}
}
-Instruction *CodeGen::MakeInstruction(uint16_t code, const ErrorCode& err) {
+Instruction* CodeGen::MakeInstruction(uint16_t code, const ErrorCode& err) {
if (BPF_CLASS(code) != BPF_RET) {
SANDBOX_DIE("ErrorCodes can only be used in return expressions");
}
@@ -170,8 +173,10 @@ Instruction *CodeGen::MakeInstruction(uint16_t code, const ErrorCode& err) {
return MakeInstruction(code, err.err_);
}
-Instruction *CodeGen::MakeInstruction(uint16_t code, uint32_t k,
- Instruction *jt, Instruction *jf) {
+Instruction* CodeGen::MakeInstruction(uint16_t code,
+ uint32_t k,
+ Instruction* jt,
+ Instruction* jf) {
// We can handle all conditional jumps. They are followed by both a
// "true" and a "false" branch.
if (BPF_CLASS(code) != BPF_JMP || BPF_OP(code) == BPF_JA) {
@@ -182,12 +187,12 @@ Instruction *CodeGen::MakeInstruction(uint16_t code, uint32_t k,
// targets. It must then be set later by calling "JoinInstructions".
SANDBOX_DIE("Branches must jump to a valid instruction");
}
- Instruction *insn = new Instruction(code, k, jt, jf);
+ Instruction* insn = new Instruction(code, k, jt, jf);
instructions_.push_back(insn);
return insn;
}
-void CodeGen::JoinInstructions(Instruction *head, Instruction *tail) {
+void CodeGen::JoinInstructions(Instruction* head, Instruction* tail) {
// Merge two instructions, or set the branch target for an "always" jump.
// This function should be called, if the caller didn't initially provide
// a value for "next" when creating the instruction.
@@ -216,11 +221,12 @@ void CodeGen::JoinInstructions(Instruction *head, Instruction *tail) {
return;
}
-void CodeGen::Traverse(Instruction *instruction,
- void (*fnc)(Instruction *, void *), void *aux) {
- std::set<Instruction *> visited;
+void CodeGen::Traverse(Instruction* instruction,
+ void (*fnc)(Instruction*, void*),
+ void* aux) {
+ std::set<Instruction*> visited;
TraverseRecursively(&visited, instruction);
- for (std::set<Instruction *>::const_iterator iter = visited.begin();
+ for (std::set<Instruction*>::const_iterator iter = visited.begin();
iter != visited.end();
++iter) {
fnc(*iter, aux);
@@ -228,15 +234,15 @@ void CodeGen::Traverse(Instruction *instruction,
}
void CodeGen::FindBranchTargets(const Instruction& instructions,
- BranchTargets *branch_targets) {
+ BranchTargets* branch_targets) {
// Follow all possible paths through the "instructions" graph and compute
// a list of branch targets. This will later be needed to compute the
// boundaries of basic blocks.
// We maintain a set of all instructions that we have previously seen. This
// set ultimately converges on all instructions in the program.
- std::set<const Instruction *> seen_instructions;
+ std::set<const Instruction*> seen_instructions;
Instructions stack;
- for (const Instruction *insn = &instructions; insn; ) {
+ for (const Instruction* insn = &instructions; insn;) {
seen_instructions.insert(insn);
if (BPF_CLASS(insn->code) == BPF_JMP) {
// Found a jump. Increase count of incoming edges for each of the jump
@@ -244,7 +250,7 @@ void CodeGen::FindBranchTargets(const Instruction& instructions,
++(*branch_targets)[insn->jt_ptr];
if (BPF_OP(insn->code) != BPF_JA) {
++(*branch_targets)[insn->jf_ptr];
- stack.push_back(const_cast<Instruction *>(insn));
+ stack.push_back(const_cast<Instruction*>(insn));
}
// Start a recursive decent for depth-first traversal.
if (seen_instructions.find(insn->jt_ptr) == seen_instructions.end()) {
@@ -262,8 +268,9 @@ void CodeGen::FindBranchTargets(const Instruction& instructions,
// (if any). It's OK if "insn" becomes NULL when reaching a return
// instruction.
if (!insn->next != (BPF_CLASS(insn->code) == BPF_RET)) {
- SANDBOX_DIE("Internal compiler error; return instruction must be at "
- "the end of the BPF program");
+ SANDBOX_DIE(
+ "Internal compiler error; return instruction must be at "
+ "the end of the BPF program");
}
if (seen_instructions.find(insn->next) == seen_instructions.end()) {
insn = insn->next;
@@ -288,8 +295,9 @@ void CodeGen::FindBranchTargets(const Instruction& instructions,
// We have seen both the "true" and the "false" branch, continue
// up the stack.
if (seen_instructions.find(insn->jt_ptr) == seen_instructions.end()) {
- SANDBOX_DIE("Internal compiler error; cannot find all "
- "branch targets");
+ SANDBOX_DIE(
+ "Internal compiler error; cannot find all "
+ "branch targets");
}
insn = NULL;
}
@@ -298,11 +306,10 @@ void CodeGen::FindBranchTargets(const Instruction& instructions,
return;
}
-BasicBlock *CodeGen::MakeBasicBlock(Instruction *head,
- Instruction *tail) {
+BasicBlock* CodeGen::MakeBasicBlock(Instruction* head, Instruction* tail) {
// Iterate over all the instructions between "head" and "tail" and
// insert them into a new basic block.
- BasicBlock *bb = new BasicBlock;
+ BasicBlock* bb = new BasicBlock;
for (;; head = head->next) {
bb->instructions.push_back(head);
if (head == tail) {
@@ -316,20 +323,21 @@ BasicBlock *CodeGen::MakeBasicBlock(Instruction *head,
return bb;
}
-void CodeGen::AddBasicBlock(Instruction *head,
- Instruction *tail,
+void CodeGen::AddBasicBlock(Instruction* head,
+ Instruction* tail,
const BranchTargets& branch_targets,
- TargetsToBlocks *basic_blocks,
- BasicBlock **firstBlock) {
+ TargetsToBlocks* basic_blocks,
+ BasicBlock** firstBlock) {
// Add a new basic block to "basic_blocks". Also set "firstBlock", if it
// has not been set before.
BranchTargets::const_iterator iter = branch_targets.find(head);
if ((iter == branch_targets.end()) != !*firstBlock ||
!*firstBlock != basic_blocks->empty()) {
- SANDBOX_DIE("Only the very first basic block should have no "
- "incoming jumps");
+ SANDBOX_DIE(
+ "Only the very first basic block should have no "
+ "incoming jumps");
}
- BasicBlock *bb = MakeBasicBlock(head, tail);
+ BasicBlock* bb = MakeBasicBlock(head, tail);
if (!*firstBlock) {
*firstBlock = bb;
}
@@ -337,19 +345,20 @@ void CodeGen::AddBasicBlock(Instruction *head,
return;
}
-BasicBlock *CodeGen::CutGraphIntoBasicBlocks(
- Instruction *instructions, const BranchTargets& branch_targets,
- TargetsToBlocks *basic_blocks) {
+BasicBlock* CodeGen::CutGraphIntoBasicBlocks(
+ Instruction* instructions,
+ const BranchTargets& branch_targets,
+ TargetsToBlocks* basic_blocks) {
// Textbook implementation of a basic block generator. All basic blocks
// start with a branch target and end with either a return statement or
// a jump (or are followed by an instruction that forms the beginning of a
// new block). Both conditional and "always" jumps are supported.
- BasicBlock *first_block = NULL;
- std::set<const Instruction *> seen_instructions;
+ BasicBlock* first_block = NULL;
+ std::set<const Instruction*> seen_instructions;
Instructions stack;
- Instruction *tail = NULL;
- Instruction *head = instructions;
- for (Instruction *insn = head; insn; ) {
+ Instruction* tail = NULL;
+ Instruction* head = instructions;
+ for (Instruction* insn = head; insn;) {
if (seen_instructions.find(insn) != seen_instructions.end()) {
// We somehow went in a circle. This should never be possible. Not even
// cyclic graphs are supposed to confuse us this much.
@@ -410,7 +419,8 @@ BasicBlock *CodeGen::CutGraphIntoBasicBlocks(
// used in a "less" comparator for the purpose of storing pointers to basic
// blocks in STL containers; this gives an easy option to use STL to find
// shared tail sequences of basic blocks.
-static int PointerCompare(const BasicBlock *block1, const BasicBlock *block2,
+static int PointerCompare(const BasicBlock* block1,
+ const BasicBlock* block2,
const TargetsToBlocks& blocks) {
// Return <0, 0, or >0 depending on the ordering of "block1" and "block2".
// If we are looking at the exact same block, this is trivial and we don't
@@ -486,7 +496,7 @@ static int PointerCompare(const BasicBlock *block1, const BasicBlock *block2,
}
}
-void CodeGen::MergeTails(TargetsToBlocks *blocks) {
+void CodeGen::MergeTails(TargetsToBlocks* blocks) {
// We enter all of our basic blocks into a set using the BasicBlock::Less()
// comparator. This naturally results in blocks with identical tails of
// instructions to map to the same entry in the set. Whenever we discover
@@ -500,12 +510,11 @@ void CodeGen::MergeTails(TargetsToBlocks *blocks) {
// the future, we might decide to revisit this decision and attempt to
// merge arbitrary sub-sequences of instructions.
BasicBlock::Less<TargetsToBlocks> less(*blocks, PointerCompare);
- typedef std::set<BasicBlock *, BasicBlock::Less<TargetsToBlocks> > Set;
+ typedef std::set<BasicBlock*, BasicBlock::Less<TargetsToBlocks> > Set;
Set seen_basic_blocks(less);
- for (TargetsToBlocks::iterator iter = blocks->begin();
- iter != blocks->end();
+ for (TargetsToBlocks::iterator iter = blocks->begin(); iter != blocks->end();
++iter) {
- BasicBlock *bb = iter->second;
+ BasicBlock* bb = iter->second;
Set::const_iterator entry = seen_basic_blocks.find(bb);
if (entry == seen_basic_blocks.end()) {
// This is the first time we see this particular sequence of
@@ -521,34 +530,36 @@ void CodeGen::MergeTails(TargetsToBlocks *blocks) {
}
}
-void CodeGen::ComputeIncomingBranches(BasicBlock *block,
+void CodeGen::ComputeIncomingBranches(BasicBlock* block,
const TargetsToBlocks& targets_to_blocks,
- IncomingBranches *incoming_branches) {
+ IncomingBranches* incoming_branches) {
// We increment the number of incoming branches each time we encounter a
// basic block. But we only traverse recursively the very first time we
// encounter a new block. This is necessary to make topological sorting
// work correctly.
if (++(*incoming_branches)[block] == 1) {
- Instruction *last_insn = block->instructions.back();
+ Instruction* last_insn = block->instructions.back();
if (BPF_CLASS(last_insn->code) == BPF_JMP) {
- ComputeIncomingBranches(
- targets_to_blocks.find(last_insn->jt_ptr)->second,
- targets_to_blocks, incoming_branches);
+ ComputeIncomingBranches(targets_to_blocks.find(last_insn->jt_ptr)->second,
+ targets_to_blocks,
+ incoming_branches);
if (BPF_OP(last_insn->code) != BPF_JA) {
ComputeIncomingBranches(
- targets_to_blocks.find(last_insn->jf_ptr)->second,
- targets_to_blocks, incoming_branches);
+ targets_to_blocks.find(last_insn->jf_ptr)->second,
+ targets_to_blocks,
+ incoming_branches);
}
} else if (BPF_CLASS(last_insn->code) != BPF_RET) {
ComputeIncomingBranches(targets_to_blocks.find(last_insn->next)->second,
- targets_to_blocks, incoming_branches);
+ targets_to_blocks,
+ incoming_branches);
}
}
}
-void CodeGen::TopoSortBasicBlocks(BasicBlock *first_block,
+void CodeGen::TopoSortBasicBlocks(BasicBlock* first_block,
const TargetsToBlocks& blocks,
- BasicBlocks *basic_blocks) {
+ BasicBlocks* basic_blocks) {
// Textbook implementation of a toposort. We keep looking for basic blocks
// that don't have any incoming branches (initially, this is just the
// "first_block") and add them to the topologically sorted list of
@@ -562,7 +573,7 @@ void CodeGen::TopoSortBasicBlocks(BasicBlock *first_block,
IncomingBranches unordered_blocks;
ComputeIncomingBranches(first_block, blocks, &unordered_blocks);
- std::set<BasicBlock *> heads;
+ std::set<BasicBlock*> heads;
for (;;) {
// Move block from "unordered_blocks" to "basic_blocks".
basic_blocks->push_back(first_block);
@@ -570,7 +581,7 @@ void CodeGen::TopoSortBasicBlocks(BasicBlock *first_block,
// Inspect last instruction in the basic block. This is typically either a
// jump or a return statement. But it could also be a "normal" instruction
// that is followed by a jump target.
- Instruction *last_insn = first_block->instructions.back();
+ Instruction* last_insn = first_block->instructions.back();
if (BPF_CLASS(last_insn->code) == BPF_JMP) {
// Remove outgoing branches. This might end up moving our descendants
// into set of "head" nodes that no longer have any incoming branches.
@@ -598,7 +609,7 @@ void CodeGen::TopoSortBasicBlocks(BasicBlock *first_block,
// Our basic block is supposed to be followed by "last_insn->next",
// but dependencies prevent this from happening. Insert a BPF_JA
// instruction to correct the code flow.
- Instruction *ja = MakeInstruction(BPF_JMP+BPF_JA, 0, last_insn->next);
+ Instruction* ja = MakeInstruction(BPF_JMP + BPF_JA, 0, last_insn->next);
first_block->instructions.push_back(ja);
last_insn->next = ja;
}
@@ -616,7 +627,7 @@ void CodeGen::TopoSortBasicBlocks(BasicBlock *first_block,
}
}
-void CodeGen::ComputeRelativeJumps(BasicBlocks *basic_blocks,
+void CodeGen::ComputeRelativeJumps(BasicBlocks* basic_blocks,
const TargetsToBlocks& targets_to_blocks) {
// While we previously used pointers in jt_ptr and jf_ptr to link jump
// instructions to their targets, we now convert these jumps to relative
@@ -626,38 +637,37 @@ void CodeGen::ComputeRelativeJumps(BasicBlocks *basic_blocks,
// Since we just completed a toposort, all jump targets are guaranteed to
// go forward. This means, iterating over the basic blocks in reverse makes
// it trivial to compute the correct offsets.
- BasicBlock *bb = NULL;
- BasicBlock *last_bb = NULL;
+ BasicBlock* bb = NULL;
+ BasicBlock* last_bb = NULL;
for (BasicBlocks::reverse_iterator iter = basic_blocks->rbegin();
iter != basic_blocks->rend();
++iter) {
last_bb = bb;
bb = *iter;
- Instruction *insn = bb->instructions.back();
+ Instruction* insn = bb->instructions.back();
if (BPF_CLASS(insn->code) == BPF_JMP) {
// Basic block ended in a jump instruction. We can now compute the
// appropriate offsets.
if (BPF_OP(insn->code) == BPF_JA) {
// "Always" jumps use the 32bit "k" field for the offset, instead
// of the 8bit "jt" and "jf" fields.
- int jmp =
- offset - targets_to_blocks.find(insn->jt_ptr)->second->offset;
- insn->k = jmp;
+ int jmp = offset - targets_to_blocks.find(insn->jt_ptr)->second->offset;
+ insn->k = jmp;
insn->jt = insn->jf = 0;
} else {
// The offset computations for conditional jumps are just the same
// as for "always" jumps.
- int jt = offset-targets_to_blocks.find(insn->jt_ptr)->second->offset;
- int jf = offset-targets_to_blocks.find(insn->jf_ptr)->second->offset;
+ int jt = offset - targets_to_blocks.find(insn->jt_ptr)->second->offset;
+ int jf = offset - targets_to_blocks.find(insn->jf_ptr)->second->offset;
// There is an added complication, because conditional relative jumps
// can only jump at most 255 instructions forward. If we have to jump
// further, insert an extra "always" jump.
Instructions::size_type jmp = bb->instructions.size();
if (jt > 255 || (jt == 255 && jf > 255)) {
- Instruction *ja = MakeInstruction(BPF_JMP+BPF_JA, 0, insn->jt_ptr);
+ Instruction* ja = MakeInstruction(BPF_JMP + BPF_JA, 0, insn->jt_ptr);
bb->instructions.push_back(ja);
- ja->k = jt;
+ ja->k = jt;
ja->jt = ja->jf = 0;
// The newly inserted "always" jump, of course, requires us to adjust
@@ -666,9 +676,9 @@ void CodeGen::ComputeRelativeJumps(BasicBlocks *basic_blocks,
++jf;
}
if (jf > 255) {
- Instruction *ja = MakeInstruction(BPF_JMP+BPF_JA, 0, insn->jf_ptr);
+ Instruction* ja = MakeInstruction(BPF_JMP + BPF_JA, 0, insn->jf_ptr);
bb->instructions.insert(bb->instructions.begin() + jmp, ja);
- ja->k = jf;
+ ja->k = jf;
ja->jt = ja->jf = 0;
// Again, we have to adjust the jump targets in the original
@@ -696,7 +706,7 @@ void CodeGen::ComputeRelativeJumps(BasicBlocks *basic_blocks,
}
void CodeGen::ConcatenateBasicBlocks(const BasicBlocks& basic_blocks,
- Sandbox::Program *program) {
+ Sandbox::Program* program) {
// Our basic blocks have been sorted and relative jump offsets have been
// computed. The last remaining step is for all the instructions in our
// basic blocks to be concatenated into a BPF program.
@@ -710,24 +720,25 @@ void CodeGen::ConcatenateBasicBlocks(const BasicBlocks& basic_blocks,
++insn_iter) {
const Instruction& insn = **insn_iter;
program->push_back(
- (struct sock_filter) { insn.code, insn.jt, insn.jf, insn.k });
+ (struct sock_filter) {insn.code, insn.jt, insn.jf, insn.k});
}
}
return;
}
-void CodeGen::Compile(Instruction *instructions, Sandbox::Program *program) {
+void CodeGen::Compile(Instruction* instructions, Sandbox::Program* program) {
if (compiled_) {
- SANDBOX_DIE("Cannot call Compile() multiple times. Create a new code "
- "generator instead");
+ SANDBOX_DIE(
+ "Cannot call Compile() multiple times. Create a new code "
+ "generator instead");
}
compiled_ = true;
BranchTargets branch_targets;
FindBranchTargets(*instructions, &branch_targets);
TargetsToBlocks all_blocks;
- BasicBlock *first_block =
- CutGraphIntoBasicBlocks(instructions, branch_targets, &all_blocks);
+ BasicBlock* first_block =
+ CutGraphIntoBasicBlocks(instructions, branch_targets, &all_blocks);
MergeTails(&all_blocks);
BasicBlocks basic_blocks;
TopoSortBasicBlocks(first_block, all_blocks, &basic_blocks);
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