Brad Bishop | 1932369 | 2019-04-05 15:28:33 -0400 | [diff] [blame^] | 1 | From 0039dbe9891cfdf2c0d04691f83c2f342993dfd7 Mon Sep 17 00:00:00 2001 |
| 2 | From: Michael Jeanson <mjeanson@efficios.com> |
| 3 | Date: Wed, 9 Jan 2019 14:59:15 -0500 |
| 4 | Subject: [PATCH 5/9] Fix: Remove 'type' argument from access_ok() function |
| 5 | (v5.0) |
| 6 | |
| 7 | See upstream commit : |
| 8 | |
| 9 | commit 96d4f267e40f9509e8a66e2b39e8b95655617693 |
| 10 | Author: Linus Torvalds <torvalds@linux-foundation.org> |
| 11 | Date: Thu Jan 3 18:57:57 2019 -0800 |
| 12 | |
| 13 | Remove 'type' argument from access_ok() function |
| 14 | |
| 15 | Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument |
| 16 | of the user address range verification function since we got rid of the |
| 17 | old racy i386-only code to walk page tables by hand. |
| 18 | |
| 19 | It existed because the original 80386 would not honor the write protect |
| 20 | bit when in kernel mode, so you had to do COW by hand before doing any |
| 21 | user access. But we haven't supported that in a long time, and these |
| 22 | days the 'type' argument is a purely historical artifact. |
| 23 | |
| 24 | A discussion about extending 'user_access_begin()' to do the range |
| 25 | checking resulted this patch, because there is no way we're going to |
| 26 | move the old VERIFY_xyz interface to that model. And it's best done at |
| 27 | the end of the merge window when I've done most of my merges, so let's |
| 28 | just get this done once and for all. |
| 29 | |
| 30 | This patch was mostly done with a sed-script, with manual fix-ups for |
| 31 | the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. |
| 32 | |
| 33 | There were a couple of notable cases: |
| 34 | |
| 35 | - csky still had the old "verify_area()" name as an alias. |
| 36 | |
| 37 | - the iter_iov code had magical hardcoded knowledge of the actual |
| 38 | values of VERIFY_{READ,WRITE} (not that they mattered, since nothing |
| 39 | really used it) |
| 40 | |
| 41 | - microblaze used the type argument for a debug printout |
| 42 | |
| 43 | but other than those oddities this should be a total no-op patch. |
| 44 | |
| 45 | I tried to fix up all architectures, did fairly extensive grepping for |
| 46 | access_ok() uses, and the changes are trivial, but I may have missed |
| 47 | something. Any missed conversion should be trivially fixable, though. |
| 48 | |
| 49 | Signed-off-by: Michael Jeanson <mjeanson@efficios.com> |
| 50 | Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 51 | |
| 52 | Upstream-Status: backport https://github.com/lttng/lttng-modules/commit/0039dbe9891cfdf2c0d04691f83c2f342993dfd7 |
| 53 | |
| 54 | Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com> |
| 55 | --- |
| 56 | lib/ringbuffer/backend.h | 8 ++++---- |
| 57 | lib/ringbuffer/ring_buffer_iterator.c | 3 ++- |
| 58 | lttng-filter-interpreter.c | 4 ++-- |
| 59 | probes/lttng-probe-user.c | 3 ++- |
| 60 | wrapper/uaccess.h | 28 +++++++++++++++++++++++++++ |
| 61 | 5 files changed, 38 insertions(+), 8 deletions(-) |
| 62 | create mode 100644 wrapper/uaccess.h |
| 63 | |
| 64 | diff --git a/lib/ringbuffer/backend.h b/lib/ringbuffer/backend.h |
| 65 | index 0b75de8..3f8c108 100644 |
| 66 | --- a/lib/ringbuffer/backend.h |
| 67 | +++ b/lib/ringbuffer/backend.h |
| 68 | @@ -34,7 +34,7 @@ |
| 69 | #include <linux/list.h> |
| 70 | #include <linux/fs.h> |
| 71 | #include <linux/mm.h> |
| 72 | -#include <linux/uaccess.h> |
| 73 | +#include <wrapper/uaccess.h> |
| 74 | |
| 75 | /* Internal helpers */ |
| 76 | #include <wrapper/ringbuffer/backend_internal.h> |
| 77 | @@ -302,7 +302,7 @@ void lib_ring_buffer_copy_from_user_inatomic(const struct lib_ring_buffer_config |
| 78 | |
| 79 | set_fs(KERNEL_DS); |
| 80 | pagefault_disable(); |
| 81 | - if (unlikely(!access_ok(VERIFY_READ, src, len))) |
| 82 | + if (unlikely(!lttng_access_ok(VERIFY_READ, src, len))) |
| 83 | goto fill_buffer; |
| 84 | |
| 85 | if (likely(pagecpy == len)) { |
| 86 | @@ -372,7 +372,7 @@ void lib_ring_buffer_strcpy_from_user_inatomic(const struct lib_ring_buffer_conf |
| 87 | |
| 88 | set_fs(KERNEL_DS); |
| 89 | pagefault_disable(); |
| 90 | - if (unlikely(!access_ok(VERIFY_READ, src, len))) |
| 91 | + if (unlikely(!lttng_access_ok(VERIFY_READ, src, len))) |
| 92 | goto fill_buffer; |
| 93 | |
| 94 | if (likely(pagecpy == len)) { |
| 95 | @@ -462,7 +462,7 @@ unsigned long lib_ring_buffer_copy_from_user_check_nofault(void *dest, |
| 96 | unsigned long ret; |
| 97 | mm_segment_t old_fs; |
| 98 | |
| 99 | - if (!access_ok(VERIFY_READ, src, len)) |
| 100 | + if (!lttng_access_ok(VERIFY_READ, src, len)) |
| 101 | return 1; |
| 102 | old_fs = get_fs(); |
| 103 | set_fs(KERNEL_DS); |
| 104 | diff --git a/lib/ringbuffer/ring_buffer_iterator.c b/lib/ringbuffer/ring_buffer_iterator.c |
| 105 | index 61eaa5b..9645946 100644 |
| 106 | --- a/lib/ringbuffer/ring_buffer_iterator.c |
| 107 | +++ b/lib/ringbuffer/ring_buffer_iterator.c |
| 108 | @@ -27,6 +27,7 @@ |
| 109 | |
| 110 | #include <wrapper/ringbuffer/iterator.h> |
| 111 | #include <wrapper/file.h> |
| 112 | +#include <wrapper/uaccess.h> |
| 113 | #include <linux/jiffies.h> |
| 114 | #include <linux/delay.h> |
| 115 | #include <linux/module.h> |
| 116 | @@ -621,7 +622,7 @@ ssize_t channel_ring_buffer_file_read(struct file *filp, |
| 117 | ssize_t len; |
| 118 | |
| 119 | might_sleep(); |
| 120 | - if (!access_ok(VERIFY_WRITE, user_buf, count)) |
| 121 | + if (!lttng_access_ok(VERIFY_WRITE, user_buf, count)) |
| 122 | return -EFAULT; |
| 123 | |
| 124 | /* Finish copy of previous record */ |
| 125 | diff --git a/lttng-filter-interpreter.c b/lttng-filter-interpreter.c |
| 126 | index e131462..bee2918 100644 |
| 127 | --- a/lttng-filter-interpreter.c |
| 128 | +++ b/lttng-filter-interpreter.c |
| 129 | @@ -24,7 +24,7 @@ |
| 130 | * SOFTWARE. |
| 131 | */ |
| 132 | |
| 133 | -#include <linux/uaccess.h> |
| 134 | +#include <wrapper/uaccess.h> |
| 135 | #include <wrapper/frame.h> |
| 136 | #include <wrapper/types.h> |
| 137 | |
| 138 | @@ -46,7 +46,7 @@ char get_char(struct estack_entry *reg, size_t offset) |
| 139 | char c; |
| 140 | |
| 141 | /* Handle invalid access as end of string. */ |
| 142 | - if (unlikely(!access_ok(VERIFY_READ, |
| 143 | + if (unlikely(!lttng_access_ok(VERIFY_READ, |
| 144 | reg->u.s.user_str + offset, |
| 145 | sizeof(c)))) |
| 146 | return '\0'; |
| 147 | diff --git a/probes/lttng-probe-user.c b/probes/lttng-probe-user.c |
| 148 | index 099a66b..ed566dd 100644 |
| 149 | --- a/probes/lttng-probe-user.c |
| 150 | +++ b/probes/lttng-probe-user.c |
| 151 | @@ -20,6 +20,7 @@ |
| 152 | |
| 153 | #include <linux/uaccess.h> |
| 154 | #include <linux/module.h> |
| 155 | +#include <wrapper/uaccess.h> |
| 156 | #include <probes/lttng-probe-user.h> |
| 157 | |
| 158 | /* |
| 159 | @@ -43,7 +44,7 @@ long lttng_strlen_user_inatomic(const char *addr) |
| 160 | char v; |
| 161 | unsigned long ret; |
| 162 | |
| 163 | - if (unlikely(!access_ok(VERIFY_READ, |
| 164 | + if (unlikely(!lttng_access_ok(VERIFY_READ, |
| 165 | (__force const char __user *) addr, |
| 166 | sizeof(v)))) |
| 167 | break; |
| 168 | diff --git a/wrapper/uaccess.h b/wrapper/uaccess.h |
| 169 | new file mode 100644 |
| 170 | index 0000000..c56427c |
| 171 | --- /dev/null |
| 172 | +++ b/wrapper/uaccess.h |
| 173 | @@ -0,0 +1,28 @@ |
| 174 | +/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1) |
| 175 | + * |
| 176 | + * wrapper/uaccess.h |
| 177 | + * |
| 178 | + * wrapper around linux/uaccess.h. |
| 179 | + * |
| 180 | + * Copyright (C) 2019 Michael Jeanson <mjeanson@efficios.com> |
| 181 | + */ |
| 182 | + |
| 183 | +#ifndef _LTTNG_WRAPPER_UACCESS_H |
| 184 | +#define _LTTNG_WRAPPER_UACCESS_H |
| 185 | + |
| 186 | +#include <linux/uaccess.h> |
| 187 | +#include <lttng-kernel-version.h> |
| 188 | + |
| 189 | +#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,0,0)) |
| 190 | + |
| 191 | +#define VERIFY_READ 0 |
| 192 | +#define VERIFY_WRITE 1 |
| 193 | +#define lttng_access_ok(type, addr, size) access_ok(addr, size) |
| 194 | + |
| 195 | +#else /* LINUX_VERSION_CODE >= KERNEL_VERSION(5,0,0) */ |
| 196 | + |
| 197 | +#define lttng_access_ok(type, addr, size) access_ok(type, addr, size) |
| 198 | + |
| 199 | +#endif /* LINUX_VERSION_CODE >= KERNEL_VERSION(5,0,0) */ |
| 200 | + |
| 201 | +#endif /* _LTTNG_WRAPPER_UACCESS_H */ |
| 202 | -- |
| 203 | 2.19.1 |
| 204 | |