From 208aae8ee0b581683bf25a602585bffc0c3968cc Mon Sep 17 00:00:00 2001 From: Evgeniy Stepanov Date: Wed, 21 May 2014 09:02:13 +0000 Subject: [msan] Chained origins re-design. Generalize StackDepot and create a new specialized instance of it to efficiently (i.e. without duplicating stack trace data) store the origin history tree. This reduces memory usage for chained origins roughly by an order of magnitude. Most importantly, this new design allows us to put two limits on stored history data (exposed in MSAN_OPTIONS) that help avoid exponential growth in used memory on certain workloads. See comments in lib/msan/msan_origin.h for more details. llvm-svn: 209284 --- compiler-rt/test/msan/chained_origin_limits.cc | 101 +++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 compiler-rt/test/msan/chained_origin_limits.cc (limited to 'compiler-rt/test/msan/chained_origin_limits.cc') diff --git a/compiler-rt/test/msan/chained_origin_limits.cc b/compiler-rt/test/msan/chained_origin_limits.cc new file mode 100644 index 00000000000..c6f8b626c59 --- /dev/null +++ b/compiler-rt/test/msan/chained_origin_limits.cc @@ -0,0 +1,101 @@ +// This test program creates a very large number of unique histories. + +// RUN: %clangxx_msan -fsanitize-memory-track-origins=2 -m64 -O3 %s -o %t + +// RUN: MSAN_OPTIONS=origin_history_size=7 not %run %t >%t.out 2>&1 +// RUN: FileCheck %s --check-prefix=CHECK7 < %t.out + +// RUN: MSAN_OPTIONS=origin_history_size=2 not %run %t >%t.out 2>&1 +// RUN: FileCheck %s --check-prefix=CHECK2 < %t.out + +// RUN: MSAN_OPTIONS=origin_history_per_stack_limit=1 not %run %t >%t.out 2>&1 +// RUN: FileCheck %s --check-prefix=CHECK-PER-STACK < %t.out + +#include +#include +#include +#include + +static char *buf, *cur, *end; +void init() { + buf = new char[1000]; + cur = buf; + end = buf + 1000; +} + +void line_flush() { + char *p; + for (p = cur - 1; p >= buf; --p) + if (*p == '\n') + break; + if (p >= buf) { + size_t write_sz = p - buf + 1; + // write(2, buf, write_sz); + memmove(buf, p + 1, end - p - 1); + cur -= write_sz; + } +} + +void buffered_write(const char *p, size_t sz) { + while (sz > 0) { + size_t copy_sz = end - cur; + if (sz < copy_sz) copy_sz = sz; + memcpy(cur, p, copy_sz); + cur += copy_sz; + sz -= copy_sz; + line_flush(); + } +} + +void fn1() { + buffered_write("a\n", 2); +} + +void fn2() { + buffered_write("a\n", 2); +} + +void fn3() { + buffered_write("a\n", 2); +} + +int main(void) { + init(); + for (int i = 0; i < 2000; ++i) { + fn1(); + fn2(); + fn3(); + } + return buf[50]; +} + +// CHECK7: WARNING: MemorySanitizer: use-of-uninitialized-value +// CHECK7-NOT: Uninitialized value was stored to memory at +// CHECK7: Uninitialized value was stored to memory at +// CHECK7-NOT: Uninitialized value was stored to memory at +// CHECK7: Uninitialized value was stored to memory at +// CHECK7-NOT: Uninitialized value was stored to memory at +// CHECK7: Uninitialized value was stored to memory at +// CHECK7-NOT: Uninitialized value was stored to memory at +// CHECK7: Uninitialized value was stored to memory at +// CHECK7-NOT: Uninitialized value was stored to memory at +// CHECK7: Uninitialized value was stored to memory at +// CHECK7-NOT: Uninitialized value was stored to memory at +// CHECK7: Uninitialized value was stored to memory at +// CHECK7-NOT: Uninitialized value was stored to memory at +// CHECK7: Uninitialized value was created by a heap allocation + +// CHECK2: WARNING: MemorySanitizer: use-of-uninitialized-value +// CHECK2-NOT: Uninitialized value was stored to memory at +// CHECK2: Uninitialized value was stored to memory at +// CHECK2-NOT: Uninitialized value was stored to memory at +// CHECK2: Uninitialized value was created by a heap allocation + +// CHECK-PER-STACK: WARNING: MemorySanitizer: use-of-uninitialized-value +// CHECK-PER-STACK: Uninitialized value was stored to memory at +// CHECK-PER-STACK: in fn3 +// CHECK-PER-STACK: Uninitialized value was stored to memory at +// CHECK-PER-STACK: in fn2 +// CHECK-PER-STACK: Uninitialized value was stored to memory at +// CHECK-PER-STACK: in fn1 +// CHECK-PER-STACK: Uninitialized value was created by a heap allocation -- cgit v1.2.3