| Message ID | 20231028195559.390407-4-adhemerval.zanella@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add a tunable to decorate anonymous memory maps | expand |
One spelling fix. One question but doesn't block LGTM. Reviewed-by: DJ Delorie <dj@redhat.com> Adhemerval Zanella <adhemerval.zanella@linaro.org> writes: > diff --git a/elf/Makefile b/elf/Makefile > + tst-decorate-maps \ Ok. > + > +$(objpfx)tst-decorate-maps: $(shared-thread-library) Ok. > diff --git a/elf/tst-decorate-maps.c b/elf/tst-decorate-maps.c > +/* Check the VMA name decoration. > + Copyright (C) 2023 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#include <stdlib.h> > +#include <string.h> > +#include <support/check.h> > +#include <support/support.h> > +#include <support/test-driver.h> > +#include <support/xstdio.h> > +#include <support/xthread.h> > +#include <support/xunistd.h> > +#include <sys/mman.h> Ok. > +#ifndef MAP_STACK > +# define MAP_STACK 0 > +#endif > + > +static pthread_barrier_t b; > + > +static void * > +tf (void *closure) > +{ > + /* Wait the thread startup, so thread stack is allocated. */ > + xpthread_barrier_wait (&b); > + > + /* Wait the test to read the process mapiping. */ Spelling: "mapping" > + xpthread_barrier_wait (&b); > + > + return NULL; > +} Ok. > +struct proc_maps_t > +{ > + int n_def_threads; > + int n_user_threads; > +}; Ok. > +static struct proc_maps_t > +read_proc_maps (void) > +{ > + if (test_verbose) > + printf ("=== print process %jd memory mapping ===\n", > + (intmax_t) getpid ()); > + struct proc_maps_t r = { 0 }; Misleading, but OK. Should be { 0, 0 }. > + > + FILE *f = xfopen ("/proc/self/maps", "r"); > + char *line = NULL; > + size_t line_len = 0; > + while (xgetline (&line, &line_len, f)) > + { > + if (test_verbose) > + printf ("%s", line); > + if (strstr (line, "[anon: glibc: pthread stack:") != NULL) > + r.n_def_threads++; > + else if (strstr (line, "[anon: glibc: pthread user stack:") != NULL) > + r.n_user_threads++; > + } > + free (line); > + xfclose (f); > + > + if (test_verbose) > + printf ("===\n"); > + return r; > +} Ok. > +static void > +do_test_threads (bool set_guard) > +{ > + enum > + { > + num_def_threads = 8, > + num_user_threads = 2, > + num_threads = num_def_threads + num_user_threads, > + }; 10 threads total, ok. > + xpthread_barrier_init (&b, NULL, num_threads + 1); Ok. > + pthread_t thr[num_threads]; > + { > + int i = 0; > + for (; i < num_threads - num_user_threads; i++) > + { > + pthread_attr_t attr; > + xpthread_attr_init (&attr); > + /* The guard page is not annotated. */ > + if (!set_guard) > + xpthread_attr_setguardsize (&attr, 0); > + thr[i] = xpthread_create (&attr, tf, NULL); > + xpthread_attr_destroy (&attr); > + } Ok. > + for (; i < num_threads; i++) > + { > + pthread_attr_t attr; > + xpthread_attr_init (&attr); > + size_t stacksize = support_small_thread_stack_size (); > + void *stack = xmmap (0, > + stacksize, > + PROT_READ | PROT_WRITE, > + MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, > + -1); > + xpthread_attr_setstack (&attr, stack, stacksize); > + if (!set_guard) > + xpthread_attr_setguardsize (&attr, 0); > + thr[i] = xpthread_create (&attr, tf, NULL); > + xpthread_attr_destroy (&attr); > + } > + } Ok. > + /* Wait all threads to finshed statup and stack allocation. */ > + xpthread_barrier_wait (&b); > + > + { > + 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); > + } Ok. > + /* Let the threads finish. */ > + xpthread_barrier_wait (&b); > + > + for (int i = 0; i < num_threads; i++) > + xpthread_join (thr[i]); > + > + { > + struct proc_maps_t r = read_proc_maps (); > + TEST_COMPARE (r.n_def_threads, 0); > + TEST_COMPARE (r.n_user_threads, 0); > + } > +} Ok. > +static int > +do_test (void) > +{ > + support_need_proc ("Reads /proc/self/maps to get stack names."); > + > + if (!support_set_vma_name ()) > + FAIL_UNSUPPORTED ("kernel does not support PR_SET_VMA_ANON_NAME"); > + > + do_test_threads (false); > + do_test_threads (true); > + > + return 0; > +} > + > +#include <support/test-driver.c> Ok. > diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c > +#include <intprops.h> > +#include <setvmaname.h> Ok. > +/* Maximum supported name from initial kernel support, not exported > + by user API. */ > +#define ANON_VMA_NAME_MAX_LEN 80 > + > +#define SET_STACK_NAME(__prefix, __stack, __stacksize, __tid) \ > + ({ \ > + char __stack_name[sizeof (__prefix) + \ > + INT_BUFSIZE_BOUND (unsigned int)]; \ > + _Static_assert (sizeof __stack_name <= ANON_VMA_NAME_MAX_LEN, \ > + "VMA name size larger than maximum supported"); \ > + __snprintf (__stack_name, sizeof (__stack_name), __prefix "%u", \ > + (unsigned int) __tid); \ > + __set_vma_name (__stack, __stacksize, __stack_name); \ > + }) Ok. > +/* Add or remove an associated name to the PD VMA stack. */ > +static void > +name_stack_maps (struct pthread *pd, bool set) > +{ > +#if _STACK_GROWS_DOWN && !defined(NEED_SEPARATE_REGISTER_STACK) > + void *stack = pd->stackblock + pd->guardsize; > +#else > + void *stack = pd->stackblock; Do we have any stack-grows-up systems to test this on? > +#endif > + size_t stacksize = pd->stackblock_size - pd->guardsize; > + > + if (!set) > + __set_vma_name (stack, stacksize, NULL); > + else > + { > + unsigned int tid = pd->tid; > + if (pd->user_stack) > + SET_STACK_NAME (" glibc: pthread user stack: ", stack, stacksize, tid); > + else > + SET_STACK_NAME (" glibc: pthread stack: ", stack, stacksize, tid); > + } > +} Ok. > diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c > /* Initialize pointers to locale data. */ > __ctype_init (); > > + /* Name the thread stack if kernel supports it. */ > + name_stack_maps (pd, true); > + Ok. > @@ -571,6 +574,9 @@ start_thread (void *arg) > /* Free the TCB. */ > __nptl_free_tcb (pd); > > + /* Remove the associated name from the thread stack. */ > + name_stack_maps (pd, false); > + > out: > /* We cannot call '_exit' here. '_exit' will terminate the process. Ok.
diff --git a/elf/Makefile b/elf/Makefile index 9176cbf1e3..a82590703c 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -303,6 +303,7 @@ tests := \ tst-array4 \ tst-array5 \ tst-auxv \ + tst-decorate-maps \ tst-dl-hash \ tst-leaks1 \ tst-stringtable \ @@ -3018,3 +3019,5 @@ LDFLAGS-tst-dlclose-lazy-mod1.so = -Wl,-z,lazy,--no-as-needed $(objpfx)tst-dlclose-lazy-mod1.so: $(objpfx)tst-dlclose-lazy-mod2.so $(objpfx)tst-dlclose-lazy.out: \ $(objpfx)tst-dlclose-lazy-mod1.so $(objpfx)tst-dlclose-lazy-mod2.so + +$(objpfx)tst-decorate-maps: $(shared-thread-library) diff --git a/elf/tst-decorate-maps.c b/elf/tst-decorate-maps.c new file mode 100644 index 0000000000..bbb7972094 --- /dev/null +++ b/elf/tst-decorate-maps.c @@ -0,0 +1,160 @@ +/* Check the VMA name decoration. + Copyright (C) 2023 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <stdlib.h> +#include <string.h> +#include <support/check.h> +#include <support/support.h> +#include <support/test-driver.h> +#include <support/xstdio.h> +#include <support/xthread.h> +#include <support/xunistd.h> +#include <sys/mman.h> + +#ifndef MAP_STACK +# define MAP_STACK 0 +#endif + +static pthread_barrier_t b; + +static void * +tf (void *closure) +{ + /* Wait the thread startup, so thread stack is allocated. */ + xpthread_barrier_wait (&b); + + /* Wait the test to read the process mapiping. */ + xpthread_barrier_wait (&b); + + return NULL; +} + +struct proc_maps_t +{ + int n_def_threads; + int n_user_threads; +}; + +static struct proc_maps_t +read_proc_maps (void) +{ + if (test_verbose) + printf ("=== print process %jd memory mapping ===\n", + (intmax_t) getpid ()); + struct proc_maps_t r = { 0 }; + + FILE *f = xfopen ("/proc/self/maps", "r"); + char *line = NULL; + size_t line_len = 0; + while (xgetline (&line, &line_len, f)) + { + if (test_verbose) + printf ("%s", line); + if (strstr (line, "[anon: glibc: pthread stack:") != NULL) + r.n_def_threads++; + else if (strstr (line, "[anon: glibc: pthread user stack:") != NULL) + r.n_user_threads++; + } + free (line); + xfclose (f); + + if (test_verbose) + printf ("===\n"); + return r; +} + +static void +do_test_threads (bool set_guard) +{ + enum + { + num_def_threads = 8, + num_user_threads = 2, + num_threads = num_def_threads + num_user_threads, + }; + + xpthread_barrier_init (&b, NULL, num_threads + 1); + + pthread_t thr[num_threads]; + { + int i = 0; + for (; i < num_threads - num_user_threads; i++) + { + pthread_attr_t attr; + xpthread_attr_init (&attr); + /* The guard page is not annotated. */ + if (!set_guard) + xpthread_attr_setguardsize (&attr, 0); + thr[i] = xpthread_create (&attr, tf, NULL); + xpthread_attr_destroy (&attr); + } + for (; i < num_threads; i++) + { + pthread_attr_t attr; + xpthread_attr_init (&attr); + size_t stacksize = support_small_thread_stack_size (); + void *stack = xmmap (0, + stacksize, + PROT_READ | PROT_WRITE, + MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, + -1); + xpthread_attr_setstack (&attr, stack, stacksize); + if (!set_guard) + xpthread_attr_setguardsize (&attr, 0); + thr[i] = xpthread_create (&attr, tf, NULL); + xpthread_attr_destroy (&attr); + } + } + + /* Wait all threads to finshed statup and stack allocation. */ + xpthread_barrier_wait (&b); + + { + 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); + } + + /* Let the threads finish. */ + xpthread_barrier_wait (&b); + + for (int i = 0; i < num_threads; i++) + xpthread_join (thr[i]); + + { + struct proc_maps_t r = read_proc_maps (); + TEST_COMPARE (r.n_def_threads, 0); + TEST_COMPARE (r.n_user_threads, 0); + } +} + +static int +do_test (void) +{ + support_need_proc ("Reads /proc/self/maps to get stack names."); + + if (!support_set_vma_name ()) + FAIL_UNSUPPORTED ("kernel does not support PR_SET_VMA_ANON_NAME"); + + do_test_threads (false); + do_test_threads (true); + + return 0; +} + +#include <support/test-driver.c> diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c index f9d8cdfd08..97d0efec10 100644 --- a/nptl/allocatestack.c +++ b/nptl/allocatestack.c @@ -33,6 +33,8 @@ #include <nptl-stack.h> #include <libc-lock.h> #include <tls-internal.h> +#include <intprops.h> +#include <setvmaname.h> /* Default alignment of stack. */ #ifndef STACK_ALIGN @@ -577,3 +579,41 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp, return 0; } + +/* Maximum supported name from initial kernel support, not exported + by user API. */ +#define ANON_VMA_NAME_MAX_LEN 80 + +#define SET_STACK_NAME(__prefix, __stack, __stacksize, __tid) \ + ({ \ + char __stack_name[sizeof (__prefix) + \ + INT_BUFSIZE_BOUND (unsigned int)]; \ + _Static_assert (sizeof __stack_name <= ANON_VMA_NAME_MAX_LEN, \ + "VMA name size larger than maximum supported"); \ + __snprintf (__stack_name, sizeof (__stack_name), __prefix "%u", \ + (unsigned int) __tid); \ + __set_vma_name (__stack, __stacksize, __stack_name); \ + }) + +/* Add or remove an associated name to the PD VMA stack. */ +static void +name_stack_maps (struct pthread *pd, bool set) +{ +#if _STACK_GROWS_DOWN && !defined(NEED_SEPARATE_REGISTER_STACK) + void *stack = pd->stackblock + pd->guardsize; +#else + void *stack = pd->stackblock; +#endif + size_t stacksize = pd->stackblock_size - pd->guardsize; + + if (!set) + __set_vma_name (stack, stacksize, NULL); + else + { + unsigned int tid = pd->tid; + if (pd->user_stack) + SET_STACK_NAME (" glibc: pthread user stack: ", stack, stacksize, tid); + else + SET_STACK_NAME (" glibc: pthread stack: ", stack, stacksize, tid); + } +} diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c index 6a41d50109..63cb684f04 100644 --- a/nptl/pthread_create.c +++ b/nptl/pthread_create.c @@ -369,6 +369,9 @@ start_thread (void *arg) /* Initialize pointers to locale data. */ __ctype_init (); + /* Name the thread stack if kernel supports it. */ + name_stack_maps (pd, true); + /* Register rseq TLS to the kernel. */ { bool do_rseq = THREAD_GETMEM (pd, flags) & ATTR_FLAG_DO_RSEQ; @@ -571,6 +574,9 @@ start_thread (void *arg) /* Free the TCB. */ __nptl_free_tcb (pd); + /* Remove the associated name from the thread stack. */ + name_stack_maps (pd, false); + out: /* We cannot call '_exit' here. '_exit' will terminate the process.