diff options
author | Abseil Team <absl-team@google.com> | 2023-04-12 06:54:17 -0700 |
---|---|---|
committer | Copybara-Service <copybara-worker@google.com> | 2023-04-12 06:55:11 -0700 |
commit | 3a46229c3cdd945ccc8bae1458148115ff8f88e7 (patch) | |
tree | 9caca54e6deb559a0839038ad1627887ba3d2acf /absl | |
parent | 5ad663b790c02c7fe11085f6ebc5e284e4432733 (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.cc | 16 | ||||
-rw-r--r-- | absl/debugging/failure_signal_handler.cc | 18 |
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; } |