From fee9e40a8da75fad9717668f6dddcc26f3feca2d Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Wed, 1 Nov 2023 09:56:08 -0300 Subject: [PATCH] malloc: Decorate malloc maps Add anonymous mmap annotations on loader malloc, malloc when it allocates memory with mmap, and on malloc arena. The /proc/self/maps will now print: [anon: glibc: malloc arena] [anon: glibc: malloc] [anon: glibc: loader malloc] On arena allocation, glibc annotates only the read/write mapping. Checked on x86_64-linux-gnu and aarch64-linux-gnu. Reviewed-by: DJ Delorie --- elf/Makefile | 4 ++++ elf/dl-minimal-malloc.c | 2 ++ elf/tst-decorate-maps.c | 36 ++++++++++++++++++++++++++++++++++++ malloc/arena.c | 4 ++++ malloc/malloc.c | 5 +++++ nptl/Makefile | 4 ++++ 6 files changed, 55 insertions(+) diff --git a/elf/Makefile b/elf/Makefile index 33f88bae96..328dbe82de 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -2983,3 +2983,7 @@ $(objpfx)tst-dlclose-lazy.out: \ $(objpfx)tst-dlclose-lazy-mod1.so $(objpfx)tst-dlclose-lazy-mod2.so $(objpfx)tst-decorate-maps: $(shared-thread-library) + +tst-decorate-maps-ENV = \ + GLIBC_TUNABLES=glibc.malloc.arena_max=8:glibc.malloc.mmap_threshold=1024 +tst-decorate-maps-ARGS = 8 diff --git a/elf/dl-minimal-malloc.c b/elf/dl-minimal-malloc.c index 27549645d0..da36986269 100644 --- a/elf/dl-minimal-malloc.c +++ b/elf/dl-minimal-malloc.c @@ -26,6 +26,7 @@ #include #include #include +#include static void *alloc_ptr, *alloc_end, *alloc_last_block; @@ -60,6 +61,7 @@ __minimal_malloc (size_t n) MAP_ANON|MAP_PRIVATE, -1, 0); if (page == MAP_FAILED) return NULL; + __set_vma_name (page, nup, " glibc: loader malloc"); if (page != alloc_end) alloc_ptr = page; alloc_end = page + nup; diff --git a/elf/tst-decorate-maps.c b/elf/tst-decorate-maps.c index b40a0e9b49..b0ea65ffd7 100644 --- a/elf/tst-decorate-maps.c +++ b/elf/tst-decorate-maps.c @@ -32,15 +32,21 @@ static pthread_barrier_t b; +static int expected_n_arenas; + static void * tf (void *closure) { + void *p = xmalloc (1024); + /* Wait the thread startup, so thread stack is allocated. */ xpthread_barrier_wait (&b); /* Wait the test to read the process mapping. */ xpthread_barrier_wait (&b); + free (p); + return NULL; } @@ -48,6 +54,9 @@ struct proc_maps_t { int n_def_threads; int n_user_threads; + int n_arenas; + int n_malloc_mmap; + int n_loader_malloc_mmap; }; static struct proc_maps_t @@ -69,6 +78,12 @@ read_proc_maps (void) r.n_def_threads++; else if (strstr (line, "[anon: glibc: pthread user stack:") != NULL) r.n_user_threads++; + else if (strstr (line, "[anon: glibc: malloc arena]") != NULL) + r.n_arenas++; + else if (strstr (line, "[anon: glibc: malloc]") != NULL) + r.n_malloc_mmap++; + else if (strstr (line, "[anon: glibc: loader malloc]") != NULL) + r.n_loader_malloc_mmap++; } free (line); xfclose (f); @@ -90,6 +105,9 @@ do_test_threads (bool set_guard) xpthread_barrier_init (&b, NULL, num_threads + 1); + /* Issue a large malloc to trigger a mmap call. */ + void *p = xmalloc (256 * 1024); + pthread_t thr[num_threads]; { int i = 0; @@ -128,6 +146,10 @@ do_test_threads (bool set_guard) struct proc_maps_t r = read_proc_maps (); TEST_COMPARE (r.n_def_threads, num_def_threads); TEST_COMPARE (r.n_user_threads, num_user_threads); + TEST_COMPARE (r.n_arenas, expected_n_arenas); + TEST_COMPARE (r.n_malloc_mmap, 1); + /* On some architectures the loader might use more than one page. */ + TEST_VERIFY (r.n_loader_malloc_mmap >= 1); } /* Let the threads finish. */ @@ -140,8 +162,22 @@ do_test_threads (bool set_guard) struct proc_maps_t r = read_proc_maps (); TEST_COMPARE (r.n_def_threads, 0); TEST_COMPARE (r.n_user_threads, 0); + TEST_COMPARE (r.n_arenas, expected_n_arenas); + TEST_COMPARE (r.n_malloc_mmap, 1); + TEST_VERIFY (r.n_loader_malloc_mmap >= 1); } + + free (p); +} + +static void +do_prepare (int argc, char *argv[]) +{ + TEST_VERIFY_EXIT (argc == 2); + expected_n_arenas = strtol (argv[1], NULL, 10); + expected_n_arenas = expected_n_arenas - 1; } +#define PREPARE do_prepare static int do_test (void) diff --git a/malloc/arena.c b/malloc/arena.c index 6f03955ff2..d1e214ac2e 100644 --- a/malloc/arena.c +++ b/malloc/arena.c @@ -17,6 +17,7 @@ not, see . */ #include +#include #define TUNABLE_NAMESPACE malloc #include @@ -436,6 +437,9 @@ alloc_new_heap (size_t size, size_t top_pad, size_t pagesize, return 0; } + /* Only considere the actual usable range. */ + __set_vma_name (p2, size, " glibc: malloc arena"); + madvise_thp (p2, size); h = (heap_info *) p2; diff --git a/malloc/malloc.c b/malloc/malloc.c index d0bbbf3710..78a531bc7a 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -218,6 +218,7 @@ #include #include +#include #include #include /* needed for malloc_stats */ @@ -2428,6 +2429,8 @@ sysmalloc_mmap (INTERNAL_SIZE_T nb, size_t pagesize, int extra_flags, mstate av) madvise_thp (mm, size); #endif + __set_vma_name (mm, size, " glibc: malloc"); + /* The offset to the start of the mmapped region is stored in the prev_size field of the chunk. This allows us to adjust returned start address to @@ -2513,6 +2516,8 @@ sysmalloc_mmap_fallback (long int *s, INTERNAL_SIZE_T nb, madvise_thp (mbrk, size); #endif + __set_vma_name (mbrk, size, " glibc: malloc"); + /* Record that we no longer have a contiguous sbrk region. After the first time mmap is used as backup, we do not ever rely on contiguous space since this could incorrectly bridge regions. */ diff --git a/nptl/Makefile b/nptl/Makefile index ffa5722e48..d969419af7 100644 --- a/nptl/Makefile +++ b/nptl/Makefile @@ -699,6 +699,10 @@ tst-audit-threads-ENV = LD_AUDIT=$(objpfx)tst-audit-threads-mod1.so tst-setuid1-static-ENV = \ LD_LIBRARY_PATH=$(ld-library-path):$(common-objpfx)elf:$(common-objpfx)nss +tst-pthread-proc-maps-ENV = \ + GLIBC_TUNABLES=glibc.malloc.arena_max=8:glibc.malloc.mmap_threshold=1024 +tst-pthread-proc-maps-ARGS = 8 + # The tests here better do not run in parallel. ifeq ($(run-built-tests),yes) ifneq ($(filter %tests,$(MAKECMDGOALS)),) -- 2.11.4.GIT