docs: sphinxify ubsan.txt and move it to dev-tools

Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --git a/Documentation/dev-tools/tools.rst b/Documentation/dev-tools/tools.rst
index 0500e65002551a3f5a03bc284b2eb4d3a4daf0e6..2d1129789753cb6f7419c8e3f0712b494e56f065 100644 (file)
--- a/Documentation/dev-tools/tools.rst
+++ b/Documentation/dev-tools/tools.rst
@@ -19,3 +19,4 @@ whole; patches welcome!
    kcov
    gcov
    kasan
+   ubsan

diff --git a/Documentation/dev-tools/ubsan.rst b/Documentation/dev-tools/ubsan.rst
new file mode 100644 (file)
index 0000000..655e6b6
--- /dev/null
+++ b/Documentation/dev-tools/ubsan.rst
@@ -0,0 +1,88 @@
+The Undefined Behavior Sanitizer - UBSAN
+========================================
+
+UBSAN is a runtime undefined behaviour checker.
+
+UBSAN uses compile-time instrumentation to catch undefined behavior (UB).
+Compiler inserts code that perform certain kinds of checks before operations
+that may cause UB. If check fails (i.e. UB detected) __ubsan_handle_*
+function called to print error message.
+
+GCC has that feature since 4.9.x [1_] (see ``-fsanitize=undefined`` option and
+its suboptions). GCC 5.x has more checkers implemented [2_].
+
+Report example
+--------------
+
+::
+
+        ================================================================================
+        UBSAN: Undefined behaviour in ../include/linux/bitops.h:110:33
+        shift exponent 32 is to large for 32-bit type 'unsigned int'
+        CPU: 0 PID: 0 Comm: swapper Not tainted 4.4.0-rc1+ #26
+         0000000000000000 ffffffff82403cc8 ffffffff815e6cd6 0000000000000001
+         ffffffff82403cf8 ffffffff82403ce0 ffffffff8163a5ed 0000000000000020
+         ffffffff82403d78 ffffffff8163ac2b ffffffff815f0001 0000000000000002
+        Call Trace:
+         [<ffffffff815e6cd6>] dump_stack+0x45/0x5f
+         [<ffffffff8163a5ed>] ubsan_epilogue+0xd/0x40
+         [<ffffffff8163ac2b>] __ubsan_handle_shift_out_of_bounds+0xeb/0x130
+         [<ffffffff815f0001>] ? radix_tree_gang_lookup_slot+0x51/0x150
+         [<ffffffff8173c586>] _mix_pool_bytes+0x1e6/0x480
+         [<ffffffff83105653>] ? dmi_walk_early+0x48/0x5c
+         [<ffffffff8173c881>] add_device_randomness+0x61/0x130
+         [<ffffffff83105b35>] ? dmi_save_one_device+0xaa/0xaa
+         [<ffffffff83105653>] dmi_walk_early+0x48/0x5c
+         [<ffffffff831066ae>] dmi_scan_machine+0x278/0x4b4
+         [<ffffffff8111d58a>] ? vprintk_default+0x1a/0x20
+         [<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
+         [<ffffffff830b2240>] setup_arch+0x405/0xc2c
+         [<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
+         [<ffffffff830ae053>] start_kernel+0x83/0x49a
+         [<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
+         [<ffffffff830ad386>] x86_64_start_reservations+0x2a/0x2c
+         [<ffffffff830ad4f3>] x86_64_start_kernel+0x16b/0x17a
+        ================================================================================
+
+Usage
+-----
+
+To enable UBSAN configure kernel with::
+
+       CONFIG_UBSAN=y
+
+and to check the entire kernel::
+
+        CONFIG_UBSAN_SANITIZE_ALL=y
+
+To enable instrumentation for specific files or directories, add a line
+similar to the following to the respective kernel Makefile:
+
+- For a single file (e.g. main.o)::
+
+    UBSAN_SANITIZE_main.o := y
+
+- For all files in one directory::
+
+    UBSAN_SANITIZE := y
+
+To exclude files from being instrumented even if
+``CONFIG_UBSAN_SANITIZE_ALL=y``, use::
+
+  UBSAN_SANITIZE_main.o := n
+
+and::
+
+  UBSAN_SANITIZE := n
+
+Detection of unaligned accesses controlled through the separate option -
+CONFIG_UBSAN_ALIGNMENT. It's off by default on architectures that support
+unaligned accesses (CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y). One could
+still enable it in config, just note that it will produce a lot of UBSAN
+reports.
+
+References
+----------
+
+.. _1: https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
+.. _2: https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html

diff --git a/Documentation/ubsan.txt b/Documentation/ubsan.txt
deleted file mode 100644 (file)
index f58215e..0000000
--- a/Documentation/ubsan.txt
+++ /dev/null
@@ -1,84 +0,0 @@
-Undefined Behavior Sanitizer - UBSAN
-
-Overview
---------
-
-UBSAN is a runtime undefined behaviour checker.
-
-UBSAN uses compile-time instrumentation to catch undefined behavior (UB).
-Compiler inserts code that perform certain kinds of checks before operations
-that may cause UB. If check fails (i.e. UB detected) __ubsan_handle_*
-function called to print error message.
-
-GCC has that feature since 4.9.x [1] (see -fsanitize=undefined option and
-its suboptions). GCC 5.x has more checkers implemented [2].
-
-Report example
----------------
-
-        ================================================================================
-        UBSAN: Undefined behaviour in ../include/linux/bitops.h:110:33
-        shift exponent 32 is to large for 32-bit type 'unsigned int'
-        CPU: 0 PID: 0 Comm: swapper Not tainted 4.4.0-rc1+ #26
-         0000000000000000 ffffffff82403cc8 ffffffff815e6cd6 0000000000000001
-         ffffffff82403cf8 ffffffff82403ce0 ffffffff8163a5ed 0000000000000020
-         ffffffff82403d78 ffffffff8163ac2b ffffffff815f0001 0000000000000002
-        Call Trace:
-         [<ffffffff815e6cd6>] dump_stack+0x45/0x5f
-         [<ffffffff8163a5ed>] ubsan_epilogue+0xd/0x40
-         [<ffffffff8163ac2b>] __ubsan_handle_shift_out_of_bounds+0xeb/0x130
-         [<ffffffff815f0001>] ? radix_tree_gang_lookup_slot+0x51/0x150
-         [<ffffffff8173c586>] _mix_pool_bytes+0x1e6/0x480
-         [<ffffffff83105653>] ? dmi_walk_early+0x48/0x5c
-         [<ffffffff8173c881>] add_device_randomness+0x61/0x130
-         [<ffffffff83105b35>] ? dmi_save_one_device+0xaa/0xaa
-         [<ffffffff83105653>] dmi_walk_early+0x48/0x5c
-         [<ffffffff831066ae>] dmi_scan_machine+0x278/0x4b4
-         [<ffffffff8111d58a>] ? vprintk_default+0x1a/0x20
-         [<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
-         [<ffffffff830b2240>] setup_arch+0x405/0xc2c
-         [<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
-         [<ffffffff830ae053>] start_kernel+0x83/0x49a
-         [<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
-         [<ffffffff830ad386>] x86_64_start_reservations+0x2a/0x2c
-         [<ffffffff830ad4f3>] x86_64_start_kernel+0x16b/0x17a
-        ================================================================================
-
-Usage
------
-
-To enable UBSAN configure kernel with:
-
-       CONFIG_UBSAN=y
-
-and to check the entire kernel:
-
-        CONFIG_UBSAN_SANITIZE_ALL=y
-
-To enable instrumentation for specific files or directories, add a line
-similar to the following to the respective kernel Makefile:
-
-        For a single file (e.g. main.o):
-                UBSAN_SANITIZE_main.o := y
-
-        For all files in one directory:
-                UBSAN_SANITIZE := y
-
-To exclude files from being instrumented even if
-CONFIG_UBSAN_SANITIZE_ALL=y, use:
-
-                UBSAN_SANITIZE_main.o := n
-        and:
-                UBSAN_SANITIZE := n
-
-Detection of unaligned accesses controlled through the separate option -
-CONFIG_UBSAN_ALIGNMENT. It's off by default on architectures that support
-unaligned accesses (CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y). One could
-still enable it in config, just note that it will produce a lot of UBSAN
-reports.
-
-References
-----------
-
-[1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
-[2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html