diff mbox series

[v3,2/7] support: Add support_set_vma_name

Message ID 20231101125611.208544-3-adhemerval.zanella@linaro.org
State Accepted
Commit ed318beab986c6f6ccf2507d4753dfea6a7b1f8d
Headers show
Series Add a tunable to decorate anonymous memory maps | expand

Commit Message

Adhemerval Zanella Nov. 1, 2023, 12:56 p.m. UTC
Check if kernel supports prctl (PR_SET_VMA, PR_SET_VMA_ANON_NAME, ...).
---
 support/Makefile                         |  1 +
 support/support.h                        |  4 ++
 support/support_set_vma_name_supported.c | 49 ++++++++++++++++++++++++
 3 files changed, 54 insertions(+)
 create mode 100644 support/support_set_vma_name_supported.c

Comments

DJ Delorie Nov. 6, 2023, 10:28 p.m. UTC | #1
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 mbox series

Patch

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
+}