tools/check-whitespace.sh: check for trailing whitespaces

File types that we don't format automatically can end up
with such basic untidiness as trailing whitespaces.
Check for these. Remove all existing precedents.

Makefile

@@ -102,7 +102,7 @@ endif
 	bin/syz-extract bin/syz-fmt \
 	extract generate generate_go generate_sys \
 	format format_go format_cpp format_sys \
-	tidy test test_race check_copyright check_language check_links check_diff check_commits \
+	tidy test test_race check_copyright check_language check_whitespace check_links check_diff check_commits \
 	presubmit presubmit_smoke presubmit_build presubmit_arch presubmit_big presubmit_race presubmit_old
 
 all: host target
@@ -266,7 +266,7 @@ presubmit:
 
 presubmit_smoke:
 	$(MAKE) generate
-	$(MAKE) -j100 check_commits check_diff check_copyright check_language check_links presubmit_build tidy
+	$(MAKE) -j100 check_commits check_diff check_copyright check_language check_whitespace check_links presubmit_build tidy
 	$(MAKE) test
 
 presubmit_build:
@@ -353,6 +353,9 @@ check_copyright:
 check_language:
 	./tools/check-language.sh
 
+check_whitespace:
+	./tools/check-whitespace.sh
+
 check_commits:
 	./tools/check-commits.sh
 

dashboard/config/util.sh

@@ -66,7 +66,7 @@ function util_add_usb_bits {
   scripts/config -d CONFIG_USB_GADGETFS
   scripts/config -d CONFIG_USB_LIBCOMPOSITE
   scripts/config -d CONFIG_USB_CONFIGFS
-  
+
   scripts/config -e CONFIG_USB_GADGET
   scripts/config -e CONFIG_USB_DUMMY_HCD
   scripts/config -e CONFIG_USB_RAW_GADGET

docs/linux/external_fuzzing_usb.md

@@ -151,48 +151,48 @@ These instructions describe how to set this up on a Raspberry Pi Zero W, but any
 
 9. Download syzkaller, apply the patch below and build `syz-executor`:
 
-    ``` c
-    diff --git a/executor/common_usb.h b/executor/common_usb.h
-    index e342d808..278c2f4e 100644
-    --- a/executor/common_usb.h
-    +++ b/executor/common_usb.h
-    @@ -269,9 +269,7 @@ static volatile long syz_usb_connect(volatile long a0, volatile long a1, volatil
-    
-            // TODO: consider creating two dummy_udc's per proc to increace the chance of
-            // triggering interaction between multiple USB devices within the same program.
-    -       char device[32];
-    -       sprintf(&device[0], "dummy_udc.%llu", procid);
-    -       rv = usb_raw_init(fd, speed, "dummy_udc", &device[0]);
-    +       rv = usb_raw_init(fd, speed, "20980000.usb", "20980000.usb");
-            if (rv < 0) {
-                    debug("syz_usb_connect: usb_raw_init failed with %d\n", rv);
-                    return rv;
-    diff --git a/executor/executor.cc b/executor/executor.cc
-    index 34949a01..1afcb288 100644
-    --- a/executor/executor.cc
-    +++ b/executor/executor.cc
-    @@ -604,8 +604,8 @@ retry:
-                            call_extra_cover = true;
-                    }
-                    if (strncmp(syscalls[call_num].name, "syz_usb_connect", strlen("syz_usb_connect")) == 0) {
-    -                       prog_extra_timeout = 2000;
-    -                       call_extra_timeout = 2000;
-    +                       prog_extra_timeout = 5000;
-    +                       call_extra_timeout = 5000;
-                    }
-                    if (strncmp(syscalls[call_num].name, "syz_usb_control_io", strlen("syz_usb_control_io")) == 0)
-                            call_extra_timeout = 300;
-    ```
+``` c
+diff --git a/executor/common_usb.h b/executor/common_usb.h
+index e342d808..278c2f4e 100644
+--- a/executor/common_usb.h
++++ b/executor/common_usb.h
+@@ -269,9 +269,7 @@ static volatile long syz_usb_connect(volatile long a0, volatile long a1, volatil
 
-    ``` bash
-    go get -u -d github.com/google/syzkaller/prog
-    cd ~/gopath/src/github.com/google/syzkaller
-    # Put the patch above into ./syzkaller.patch
-    git apply ./syzkaller.patch
-    make executor
-    mkdir ~/syz-bin
-    cp bin/linux_arm/syz-executor ~/syz-bin/
-    ```
+    // TODO: consider creating two dummy_udc's per proc to increace the chance of
+    // triggering interaction between multiple USB devices within the same program.
+-       char device[32];
+-       sprintf(&device[0], "dummy_udc.%llu", procid);
+-       rv = usb_raw_init(fd, speed, "dummy_udc", &device[0]);
++       rv = usb_raw_init(fd, speed, "20980000.usb", "20980000.usb");
+    if (rv < 0) {
+            debug("syz_usb_connect: usb_raw_init failed with %d\n", rv);
+            return rv;
+diff --git a/executor/executor.cc b/executor/executor.cc
+index 34949a01..1afcb288 100644
+--- a/executor/executor.cc
++++ b/executor/executor.cc
+@@ -604,8 +604,8 @@ retry:
+                    call_extra_cover = true;
+            }
+            if (strncmp(syscalls[call_num].name, "syz_usb_connect", strlen("syz_usb_connect")) == 0) {
+-                       prog_extra_timeout = 2000;
+-                       call_extra_timeout = 2000;
++                       prog_extra_timeout = 5000;
++                       call_extra_timeout = 5000;
+            }
+            if (strncmp(syscalls[call_num].name, "syz_usb_control_io", strlen("syz_usb_control_io")) == 0)
+                    call_extra_timeout = 300;
+```
+
+``` bash
+go get -u -d github.com/google/syzkaller/prog
+cd ~/gopath/src/github.com/google/syzkaller
+# Put the patch above into ./syzkaller.patch
+git apply ./syzkaller.patch
+make executor
+mkdir ~/syz-bin
+cp bin/linux_arm/syz-executor ~/syz-bin/
+```
 
 10. Build `syz-execprog` on your host machine for arm32 with `make TARGETARCH=arm execprog` and copy to `~/syz-bin` onto the SD card. You may try building syz-execprog on the Raspberry Pi itself, but that worked poorly for me due to large memory consumption during the compilation process.
 

docs/linux/setup_linux-host_android-device_arm-kernel.md

@@ -5,7 +5,7 @@
 This document details the steps involved in setting up a syzkaller instance fuzzing an `arm32/64` linux kernel on an Android device.
 
 Some features of syzkaller may not yet work properly on `arm32`. For example, not all debugging and test coverage features are available in the Linux kernel for `arm32`, limiting the efficacy of syskaller in finding bugs fast.
- 
+
 These were tested on an NXP Pico-Pi-IMX7D following the instructions [here](https://developer.android.com/things/hardware/developer-kits.html).
 
 You may find additional details in syzkaller's `adb` vm implementation [here](/vm/adb/adb.go).

docs/linux/setup_linux-host_qemu-vm_arm-kernel.md

@@ -5,7 +5,7 @@
 Obtain a fresh `arm-linux-gnueabihf-gcc`. Latest Debian distributions provide
 version 7.2.0, which should be enough. Otherwise you can download Linaro
 compiler [here](https://www.linaro.org/downloads).
- 
+
 # Kernel
 
 The instructions are tested with `v4.16.1`. Check that you have/backport
@@ -77,7 +77,7 @@ debugfs	/sys/kernel/debug	debugfs	defaults	0	0
 ```
 
 Then replace `output/target/etc/ssh/sshd_config` with the following contents:
- 
+
 ```
 PermitRootLogin yes
 PasswordAuthentication yes

docs/linux/setup_linux-host_qemu-vm_arm64-kernel.md

@@ -109,7 +109,7 @@ At the top of /etc/init.d/S50sshd add the following lines:
     mount -t debugfs none /sys/kernel/debug
     chmod 777 /sys/kernel/debug/kcov
 
-Comment out the line 
+Comment out the line
 
     /usr/bin/ssh-keygen -A
 

docs/linux/setup_linux-host_qemu-vm_s390x-kernel.md

@@ -75,7 +75,7 @@ Now you should have `vmlinux` (kernel binary) and `bzImage` (packed kernel image
 ``` bash
 $ ls $KERNEL/vmlinux
 $KERNEL/vmlinux
-$ ls $KERNEL/arch/s390/boot/bzImage 
+$ ls $KERNEL/arch/s390/boot/bzImage
 $KERNEL/arch/s390/boot/bzImage
 ```
 

docs/linux/setup_ubuntu-host_odroid-c2-board_arm64-kernel.md

@@ -80,7 +80,7 @@ Some message
 
     ``` bash
     $ ssh root@172.16.0.31
-    root@172.16.0.31's password: 
+    root@172.16.0.31's password:
     ...
     Last login: Thu Feb 11 11:30:51 2016
     root@odroid64:~#
@@ -93,7 +93,7 @@ This hub has support for a feature called [Per Port Power Switching](http://www.
 
 [To be able to open the hub device entry](http://www.janosgyerik.com/adding-udev-rules-for-usb-debugging-android-devices/) under `/dev/` without being root, add the following file to `/etc/udev/rules.d/` on the host machine:
 ``` bash
-$ cat /etc/udev/rules.d/10-local.rules 
+$ cat /etc/udev/rules.d/10-local.rules
 SUBSYSTEM=="usb", ATTR{idVendor}=="2001", ATTR{idProduct}=="f103", MODE="0664", GROUP="plugdev"
 ```
 
@@ -101,7 +101,7 @@ SUBSYSTEM=="usb", ATTR{idVendor}=="2001", ATTR{idProduct}=="f103", MODE="0664",
 Don't forget to replug the hub after you add this file.
 
 ``` bash
-$ lsusb 
+$ lsusb
 ...
 Bus 003 Device 026: ID 2001:f103 D-Link Corp. DUB-H7 7-port USB 2.0 hub
 ...
@@ -159,14 +159,14 @@ index 165cf9783a5d..ff8b40dca9e2 100644
 @@ -653,6 +653,11 @@ KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
  # Tell gcc to never replace conditional load with a non-conditional one
  KBUILD_CFLAGS  += $(call cc-option,--param=allow-store-data-races=0)
- 
+
 +# Stop gcc from converting switches into a form that defeats dead code
 +# elimination and can subsequently lead to calls to intentionally
 +# undefined functions appearing in the final link.
 +KBUILD_CFLAGS  += $(call cc-option,--param=max-fsm-thread-path-insns=1)
 +
  include scripts/Makefile.gcc-plugins
- 
+
  ifdef CONFIG_READABLE_ASM
 ```
 
@@ -177,12 +177,12 @@ index 9576775a86f6..8bc4eb36fc1b 100644
 --- a/scripts/Makefile.kasan
 +++ b/scripts/Makefile.kasan
 @@ -11,7 +11,6 @@ CFLAGS_KASAN_MINIMAL := -fsanitize=kernel-address
- 
+
  CFLAGS_KASAN := $(call cc-option, -fsanitize=kernel-address \
                 -fasan-shadow-offset=$(KASAN_SHADOW_OFFSET) \
 -               --param asan-stack=1 --param asan-globals=1 \
                 --param asan-instrumentation-with-call-threshold=$(call_threshold))
- 
+
  ifeq ($(call cc-option, $(CFLAGS_KASAN_MINIMAL) -Werror),)
 ```
 

docs/linux/setup_ubuntu-host_qemu-vm_x86-64-kernel.md

@@ -70,7 +70,7 @@ Now you should have `vmlinux` (kernel binary) and `bzImage` (packed kernel image
 ``` bash
 $ ls $KERNEL/vmlinux
 $KERNEL/vmlinux
-$ ls $KERNEL/arch/x86/boot/bzImage 
+$ ls $KERNEL/arch/x86/boot/bzImage
 $KERNEL/arch/x86/boot/bzImage
 ```
 

docs/pseudo_syscalls.md

@@ -4,7 +4,7 @@ Besides regular system calls, a [syscall
 description](syscall_descriptions.md) file can also contain
 pseudo-syscalls. These are C functions defined in the
 executor. When a test program uses a pseudo-syscall, the executor
-will generate the pseudo-syscall function code in the resulting C program. 
+will generate the pseudo-syscall function code in the resulting C program.
 
 This allows a test program to have specific code blocks to perform
 certain actions, they may also be used as more test-friendly wrappers

docs/syscall_descriptions.md

@@ -170,7 +170,7 @@ close(r0)
 
 Syscall arguments are always `in`, return values are `out` and pointer indirections
 have explicit direction as `ptr` type attribute. Also, it is possible to specify
-direction attribute individually for struct fields to account for more complex 
+direction attribute individually for struct fields to account for more complex
 producer/consumer scenarious with structs that include both input/output resources.
 
 <div id="values"/>

docs/syscall_descriptions_syntax.md

@@ -365,7 +365,7 @@ define MY_PATH_MAX	PATH_MAX + 2
 ## Misc
 
 Description files also contain `include` directives that refer to Linux kernel header files,
-`incdir` directives that refer to custom Linux kernel header directories 
+`incdir` directives that refer to custom Linux kernel header directories
 and `define` directives that define symbolic constant values.
 
 The syzkaller executor defines some [pseudo system calls](./pseudo_syscalls.md)

docs/syzbot.md

@@ -176,7 +176,7 @@ Suggestions and patches that improve bisection quality for common cases are
 `syzbot` supports cause bisection (find the commit that introduces a bug) and
 fix bisection (find the commit that fixes a bug).
 
-The web UI for a specific kernel 
+The web UI for a specific kernel
 (say [upstream linux](https://syzkaller.appspot.com/upstream)) shows the
 `Bisected` status for all bugs.
 
@@ -227,7 +227,7 @@ the provided crash report on the provided reproducer on a freshly-booted
 machine, so the reproducer worked for it somehow.
 
 Note: if the report contains `userspace arch: i386`,
-then the program needs to be built with `-m32` flag. 
+then the program needs to be built with `-m32` flag.
 
 `syzbot` uses GCE VMs for testing, but *usually* it is not important.
 
@@ -405,7 +405,7 @@ ask tree maintainers for priority handling.
 However, syzbot kernel config always includes `CONFIG_DEBUG_AID_FOR_SYZBOT=y` setting,
 which is not normally present in kernel. What was used for particularly elusive bugs in the past
 is temporary merging some additional debugging code into `linux-next` under this config setting
-(e.g. more debug checks and/or debug output) and waiting for new crash reports from syzbot. 
+(e.g. more debug checks and/or debug output) and waiting for new crash reports from syzbot.
 
 ## Kernel configs
 

docs/trusty/README.md

@@ -151,7 +151,7 @@ using config along the lines of (substitute actual values for `$KERNEL`, `$SYZKA
 		"ppoll",
 		"dup3",
 		"tkill",
-		"gettid",		
+		"gettid",
 		"close"
 	]
 }

tools/check-whitespace.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+# Copyright 2020 syzkaller project authors. All rights reserved.
+# Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+FILES=0
+FAILED=""
+RE="[[:space:]]$"
+LAST_EMPTY=""
+for F in $(find . -name "*.sh" -o -name "*.S" -o -name "*.py" -o -name "*.yml" -o -name "*.yaml" -o -name "*.md" | \
+		egrep -v "/vendor/|/gen/"); do
+	((FILES+=1))
+	L=0
+	while IFS= read -r LINE; do
+		((L+=1))
+		if [[ $LINE =~ $RE ]]; then
+			echo "$F:$L:1: Trailing whitespace at the end of the line. Please remove."
+			echo "$LINE"
+			FAILED="1"
+		fi
+		LAST_EMPTY=""
+		if [ "$LINE" == "" ]; then
+			LAST_EMPTY="1"
+		fi
+	done < "$F"
+	if [ "$LAST_EMPTY" != "" ]; then
+		echo "$F:$L:1: Trailing empty line at the end of the file. Please remove."
+		FAILED="1"
+	fi
+done
+if [ "$FAILED" != "" ]; then exit 1; fi
+echo "$FILES files checked for whitespaces"

tools/create_f2fs_image.sh

@@ -22,7 +22,7 @@ for op1 in "${Op1[@]}"; do
       for op4 in "${Op4[@]}"; do
         echo mkfs.f2fs ${op1}${op2}${op3}${op4} disk.raw
         fallocate -l 64M disk.raw
-        mkfs.f2fs "${op1}${op2}${op3}${op4}" disk.raw 
+        mkfs.f2fs "${op1}${op2}${op3}${op4}" disk.raw
         out="$dir/../sys/linux/test/syz_mount_image_f2fs_$dex"
         echo "# Code generated by tools/create_f2fs_image.sh. DO NOT EDIT." > $out
         echo "# requires: manual" >> $out
@@ -34,4 +34,3 @@ for op1 in "${Op1[@]}"; do
     done
   done
 done
-