Merge pull request #9430 from hercules-ci/remove-vlas

Fix stack overflow in `filter`

(cherry picked from commit cb7f25869d)
Change-Id: Ib90f97a9805bbb4d0e2741551d490f054fc0a675
This commit is contained in:
eldritch horrors 2024-03-04 06:18:20 +01:00
parent a089d8f5f6
commit 001be52794
5 changed files with 70 additions and 9 deletions

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@ -0,0 +1,12 @@
diff --git a/include/gc_allocator.h b/include/gc_allocator.h
index 597c7f13..587286be 100644
--- a/include/gc_allocator.h
+++ b/include/gc_allocator.h
@@ -312,6 +312,7 @@ public:
template<>
class traceable_allocator<void> {
+public:
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef void* pointer;

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@ -228,6 +228,9 @@
}).overrideAttrs(o: {
patches = (o.patches or []) ++ [
./boehmgc-coroutine-sp-fallback.diff
# https://github.com/ivmai/bdwgc/pull/586
./boehmgc-traceable_allocator-public.diff
];
})
)

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@ -13,6 +13,7 @@
#include "function-trace.hh"
#include "profiles.hh"
#include "print.hh"
#include "gc-small-vector.hh"
#include <algorithm>
#include <chrono>
@ -28,6 +29,7 @@
#include <sys/resource.h>
#include <nlohmann/json.hpp>
#include <boost/container/small_vector.hpp>
#if HAVE_BOEHMGC
@ -1701,7 +1703,7 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value &
/* We have all the arguments, so call the primop with
the previous and new arguments. */
Value * vArgs[arity];
Value * vArgs[maxPrimOpArity];
auto n = argsDone;
for (Value * arg = &vCur; arg->isPrimOpApp(); arg = arg->primOpApp.left)
vArgs[--n] = arg->primOpApp.right;
@ -1764,11 +1766,11 @@ void ExprCall::eval(EvalState & state, Env & env, Value & v)
// 4: about 60
// 5: under 10
// This excluded attrset lambdas (`{...}:`). Contributions of mixed lambdas appears insignificant at ~150 total.
Value * vArgs[args.size()];
SmallValueVector<4> vArgs(args.size());
for (size_t i = 0; i < args.size(); ++i)
vArgs[i] = args[i]->maybeThunk(state, env);
state.callFunction(vFun, args.size(), vArgs, v, pos);
state.callFunction(vFun, args.size(), vArgs.data(), v, pos);
}
@ -2007,8 +2009,9 @@ void ExprConcatStrings::eval(EvalState & state, Env & env, Value & v)
return result;
};
Value values[es->size()];
Value * vTmpP = values;
// List of returned strings. References to these Values must NOT be persisted.
SmallTemporaryValueVector<conservativeStackReservation> values(es->size());
Value * vTmpP = values.data();
for (auto & [i_pos, i] : *es) {
Value & vTmp = *vTmpP++;

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@ -0,0 +1,42 @@
#pragma once
#include <boost/container/small_vector.hpp>
#if HAVE_BOEHMGC
#include <gc/gc.h>
#include <gc/gc_cpp.h>
#include <gc/gc_allocator.h>
#endif
namespace nix {
struct Value;
/**
* A GC compatible vector that may used a reserved portion of `nItems` on the stack instead of allocating on the heap.
*/
#if HAVE_BOEHMGC
template <typename T, size_t nItems>
using SmallVector = boost::container::small_vector<T, nItems, traceable_allocator<T>>;
#else
template <typename T, size_t nItems>
using SmallVector = boost::container::small_vector<T, nItems>;
#endif
/**
* A vector of value pointers. See `SmallVector`.
*/
template <size_t nItems>
using SmallValueVector = SmallVector<Value *, nItems>;
/**
* A vector of values that must not be referenced after the vector is destroyed.
*
* See also `SmallValueVector`.
*/
template <size_t nItems>
using SmallTemporaryValueVector = SmallVector<Value, nItems>;
}

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@ -4,6 +4,7 @@
#include "eval-inline.hh"
#include "eval.hh"
#include "eval-settings.hh"
#include "gc-small-vector.hh"
#include "globals.hh"
#include "json-to-value.hh"
#include "names.hh"
@ -2726,7 +2727,7 @@ static void prim_catAttrs(EvalState & state, const PosIdx pos, Value * * args, V
auto attrName = state.symbols.create(state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.catAttrs"));
state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.catAttrs");
Value * res[args[1]->listSize()];
SmallValueVector<nonRecursiveStackReservation> res(args[1]->listSize());
size_t found = 0;
for (auto v2 : args[1]->listItems()) {
@ -3061,8 +3062,7 @@ static void prim_filter(EvalState & state, const PosIdx pos, Value * * args, Val
state.forceFunction(*args[0], pos, "while evaluating the first argument passed to builtins.filter");
// FIXME: putting this on the stack is risky.
Value * vs[args[1]->listSize()];
SmallValueVector<nonRecursiveStackReservation> vs(args[1]->listSize());
size_t k = 0;
bool same = true;
@ -3451,7 +3451,8 @@ static void prim_concatMap(EvalState & state, const PosIdx pos, Value * * args,
state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.concatMap");
auto nrLists = args[1]->listSize();
Value lists[nrLists];
// List of returned lists before concatenation. References to these Values must NOT be persisted.
SmallTemporaryValueVector<conservativeStackReservation> lists(nrLists);
size_t len = 0;
for (unsigned int n = 0; n < nrLists; ++n) {