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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2023-11-01 09:56:08 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2023-11-07 10:27:20 -0300
commitfee9e40a8da75fad9717668f6dddcc26f3feca2d (patch)
tree318af06cfcad98364192c6b01bb2a0ed6a08b577 /elf
parent6afce56c197ee83520994a2c94a82c2ca2bce9fa (diff)
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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 <dj@redhat.com>
Diffstat (limited to 'elf')
-rw-r--r--elf/Makefile4
-rw-r--r--elf/dl-minimal-malloc.c2
-rw-r--r--elf/tst-decorate-maps.c36
3 files changed, 42 insertions, 0 deletions
diff --git a/elf/Makefile b/elf/Makefile
index 33f88ba..328dbe8 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 2754964..da36986 100644
--- a/elf/dl-minimal-malloc.c
+++ b/elf/dl-minimal-malloc.c
@@ -26,6 +26,7 @@
#include <string.h>
#include <ldsodefs.h>
#include <malloc/malloc-internal.h>
+#include <setvmaname.h>
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 b40a0e9..b0ea65f 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)