| Message ID | 20231101125611.208544-3-adhemerval.zanella@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | Add a tunable to decorate anonymous memory maps | expand |
LGTM Reviewed-by: DJ Delorie <dj@redhat.com> Adhemerval Zanella <adhemerval.zanella@linaro.org> writes: > diff --git a/support/Makefile b/support/Makefile > index 917a858bd1..9aa7f23a6e 100644 > --- a/support/Makefile > +++ b/support/Makefile > @@ -80,6 +80,7 @@ libsupport-routines = \ > support_select_modifies_timeout \ > support_select_normalizes_timeout \ > support_set_small_thread_stack_size \ > + support_set_vma_name_supported \ > support_shared_allocate \ > support_small_stack_thread_attribute \ > support_socket_so_timestamp_time64 \ > diff --git a/support/support.h b/support/support.h > index b7f76bf080..4a068d3aee 100644 > --- a/support/support.h > +++ b/support/support.h > @@ -235,6 +235,10 @@ void support_stack_free (struct support_stack *stack); > The returned value is the lowest file descriptor number. */ > int support_open_dev_null_range (int num, int flags, mode_t mode); > > + > +/* Check if kernel supports set VMA range name. */ > +extern bool support_set_vma_name_supported (void); > + > __END_DECLS > > #endif /* SUPPORT_H */ > diff --git a/support/support_set_vma_name_supported.c b/support/support_set_vma_name_supported.c > new file mode 100644 > index 0000000000..712caa9b9b > --- /dev/null > +++ b/support/support_set_vma_name_supported.c > @@ -0,0 +1,49 @@ > +/* Check if kernel supports set VMA range name. > + 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 <support/check.h> > +#include <support/support.h> > +#include <support/xunistd.h> > +#include <sys/mman.h> > +#ifdef __linux__ > +# include <sys/prctl.h> > +#endif > + > +bool > +support_set_vma_name_supported (void) > +{ > +#ifdef __linux__ > + size_t size = sysconf (_SC_PAGESIZE); > + if (size == -1) > + FAIL_EXIT1 ("sysconf (_SC_PAGESIZE): %m\n"); > + > + void *vma = xmmap (0, > + size, > + PROT_NONE, > + MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, > + -1); > + > + int r = prctl (PR_SET_VMA, PR_SET_VMA_ANON_NAME, vma, size, "vmaname"); > + > + xmunmap (vma, size); > + > + return r == 0; > +#else > + return false; > +#endif > +}
diff --git a/support/Makefile b/support/Makefile index 917a858bd1..9aa7f23a6e 100644 --- a/support/Makefile +++ b/support/Makefile @@ -80,6 +80,7 @@ libsupport-routines = \ support_select_modifies_timeout \ support_select_normalizes_timeout \ support_set_small_thread_stack_size \ + support_set_vma_name_supported \ support_shared_allocate \ support_small_stack_thread_attribute \ support_socket_so_timestamp_time64 \ diff --git a/support/support.h b/support/support.h index b7f76bf080..4a068d3aee 100644 --- a/support/support.h +++ b/support/support.h @@ -235,6 +235,10 @@ void support_stack_free (struct support_stack *stack); The returned value is the lowest file descriptor number. */ int support_open_dev_null_range (int num, int flags, mode_t mode); + +/* Check if kernel supports set VMA range name. */ +extern bool support_set_vma_name_supported (void); + __END_DECLS #endif /* SUPPORT_H */ diff --git a/support/support_set_vma_name_supported.c b/support/support_set_vma_name_supported.c new file mode 100644 index 0000000000..712caa9b9b --- /dev/null +++ b/support/support_set_vma_name_supported.c @@ -0,0 +1,49 @@ +/* Check if kernel supports set VMA range name. + 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 <support/check.h> +#include <support/support.h> +#include <support/xunistd.h> +#include <sys/mman.h> +#ifdef __linux__ +# include <sys/prctl.h> +#endif + +bool +support_set_vma_name_supported (void) +{ +#ifdef __linux__ + size_t size = sysconf (_SC_PAGESIZE); + if (size == -1) + FAIL_EXIT1 ("sysconf (_SC_PAGESIZE): %m\n"); + + void *vma = xmmap (0, + size, + PROT_NONE, + MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, + -1); + + int r = prctl (PR_SET_VMA, PR_SET_VMA_ANON_NAME, vma, size, "vmaname"); + + xmunmap (vma, size); + + return r == 0; +#else + return false; +#endif +}