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authorGravatar Abseil Team <absl-team@google.com>2023-04-12 06:54:17 -0700
committerGravatar Copybara-Service <copybara-worker@google.com>2023-04-12 06:55:11 -0700
commit3a46229c3cdd945ccc8bae1458148115ff8f88e7 (patch)
tree9caca54e6deb559a0839038ad1627887ba3d2acf /absl
parent5ad663b790c02c7fe11085f6ebc5e284e4432733 (diff)
Name anonymous memory allocations on Linux.
Use Linux's prctl(PR_SET_VMA) system call to name memory arenas being allocated using mmap(MAP_ANONYMOUS). This change allows Abseil's memory arena(s) to be distinguished from other uses of anonymous memory within a process, which in turn helps investigations into the memory usage of applications. The change adds a new prctl() system call to the code paths that call mmap(). This is not expected to add significant overhead to applications. The call to prctl(PR_SET_VMA, ...) can fail if the Linux kernel in use was not configured with the CONFIG_ANON_VMA_NAME kernel option. This should be OK since the naming memory regions is primarily a debugging aid. PiperOrigin-RevId: 523687348 Change-Id: Ie404e5eeef0a6da53330b3a56149c4f3bc6bf5c7
Diffstat (limited to 'absl')
-rw-r--r--absl/base/internal/low_level_alloc.cc16
-rw-r--r--absl/debugging/failure_signal_handler.cc18
2 files changed, 34 insertions, 0 deletions
diff --git a/absl/base/internal/low_level_alloc.cc b/absl/base/internal/low_level_alloc.cc
index 3f888f2f..f8c4336f 100644
--- a/absl/base/internal/low_level_alloc.cc
+++ b/absl/base/internal/low_level_alloc.cc
@@ -42,6 +42,10 @@
#include <windows.h>
#endif
+#ifdef __linux__
+#include <sys/prctl.h>
+#endif
+
#include <string.h>
#include <algorithm>
#include <atomic>
@@ -570,6 +574,18 @@ static void *DoAllocWithArena(size_t request, LowLevelAlloc::Arena *arena) {
ABSL_RAW_LOG(FATAL, "mmap error: %d", errno);
}
+#ifdef __linux__
+#if defined(PR_SET_VMA) && defined(PR_SET_VMA_ANON_NAME)
+ // Attempt to name the allocated address range in /proc/$PID/smaps on
+ // Linux.
+ //
+ // This invocation of prctl() may fail if the Linux kernel was not
+ // configured with the CONFIG_ANON_VMA_NAME option. This is OK since
+ // the naming of arenas is primarily a debugging aid.
+ prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, new_pages, new_pages_size,
+ "absl");
+#endif
+#endif // __linux__
#endif // _WIN32
arena->mu.Lock();
s = reinterpret_cast<AllocList *>(new_pages);
diff --git a/absl/debugging/failure_signal_handler.cc b/absl/debugging/failure_signal_handler.cc
index ef8ab9e5..9f399d02 100644
--- a/absl/debugging/failure_signal_handler.cc
+++ b/absl/debugging/failure_signal_handler.cc
@@ -33,6 +33,10 @@
#include <sys/mman.h>
#endif
+#ifdef __linux__
+#include <sys/prctl.h>
+#endif
+
#include <algorithm>
#include <atomic>
#include <cerrno>
@@ -172,6 +176,20 @@ static bool SetupAlternateStackOnce() {
if (sigaltstack(&sigstk, nullptr) != 0) {
ABSL_RAW_LOG(FATAL, "sigaltstack() failed with errno=%d", errno);
}
+
+#ifdef __linux__
+#if defined(PR_SET_VMA) && defined(PR_SET_VMA_ANON_NAME)
+ // Make a best-effort attempt to name the allocated region in
+ // /proc/$PID/smaps.
+ //
+ // The call to prctl() may fail if the kernel was not configured with the
+ // CONFIG_ANON_VMA_NAME kernel option. This is OK since the call is
+ // primarily a debugging aid.
+ prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, sigstk.ss_sp, sigstk.ss_size,
+ "absl-signalstack");
+#endif
+#endif // __linux__
+
return true;
}