Enable FORTIFY_SOURCE so running Kunit tests can test fortified
functions.
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/r/20220210003224.773957-1-keescook@chromium.org

Clarify the LKDTM FORTIFY tests, and add tests for the mem*() family of
functions, now that run-time checking is distinct.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>

Enable run-time checking of dynamic memcpy() and memmove() lengths,
issuing a WARN when a write would exceed the size of the target struct
member, when built with CONFIG_FORTIFY_SOURCE=y. This would have
caught all of the memcpy()-based buffer overflows in the last 3 years,
specifically covering all the cases where the destination buffer size
is known at compile time.

This change ONLY adds a run-time warning. As false positives are currently
still expected, this will not block the overflow. The new warnings will
look like this:

  memcpy: detected field-spanning write (size N) of single field "var->dest" (size M)
  WARNING: CPU: n PID: pppp at source/file/path.c:nr function+0xXX/0xXX [module]

There may be false positives in the kernel where intentional
field-spanning writes are happening. These need to be addressed
similarly to how the compile-time cases were addressed: add a
struct_group(), split the memcpy(), or some other refactoring.

In order to make counting/investigating instances of added runtime checks
easier, each instance includes the destination variable name as a WARN
argument, prefixed with 'field "'. Therefore, on an x86_64 defconfig
build, it is trivial to inspect the build artifacts to find instances.
For example on an x86_64 defconfig build, there are 78 new run-time
memcpy() bounds checks added:

  $ for i in vmlinux $(find . -name '*.ko'); do \
      strings "$i" | grep '^field "'; done | wc -l
  78

Simple cases where a destination buffer is known to be a dynamic size
do not generate a WARN. For example:

struct normal_flex_array {
	void *a;
	int b;
	u32 c;
	size_t array_size;
	u8 flex_array[];
};

struct normal_flex_array *instance;
...
/* These will be ignored for run-time bounds checking. */
memcpy(instance, src, len);
memcpy(instance->flex_array, src, len);

However, one of the dynamic-sized destination cases is irritatingly
unable to be detected by the compiler: when using memcpy() to target
a composite struct member which contains a trailing flexible array
struct. For example:

struct wrapper {
	int foo;
	char bar;
	struct normal_flex_array embedded;
};

struct wrapper *instance;
...
/* This will incorrectly WARN when len > sizeof(instance->embedded) */
memcpy(&instance->embedded, src, len);

These cases end up appearing to the compiler to be sized as if the
flexible array had 0 elements. :( For more details see:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101832
https://godbolt.org/z/vW6x8vh4P

These "composite flexible array structure destination" cases will be
need to be flushed out and addressed on a case-by-case basis.

Regardless, for the general case of using memcpy() on flexible array
destinations, future APIs will be created to handle common cases. Those
can be used to migrate away from open-coded memcpy() so that proper
error handling (instead of trapping) can be used.

As mentioned, none of these bounds checks block any overflows
currently. For users that have tested their workloads, do not encounter
any warnings, and wish to make these checks stop any overflows, they
can use a big hammer and set the sysctl panic_on_warn=1.
Signed-off-by: Kees Cook <keescook@chromium.org>

Clean up uses of "(size_t)-1" in favor of SIZE_MAX.

Cc: linux-hardening@vger.kernel.org
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

Add lib/fortify_kunit.c KUnit test for checking the expected behavioral
characteristics of FORTIFY_SOURCE internals.

Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Tom Rix <trix@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: "Steven Rostedt (Google)" <rostedt@goodmis.org>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Sander Vanheule <sander@svanheule.net>
Cc: linux-hardening@vger.kernel.org
Cc: llvm@lists.linux.dev
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

With CONFIG_FORTIFY=y and CONFIG_UBSAN_LOCAL_BOUNDS=y enabled, we observe
a runtime panic while running Android's Compatibility Test Suite's (CTS)
android.hardware.input.cts.tests. This is stemming from a strlen()
call in hidinput_allocate().

__compiletime_strlen() is implemented in terms of __builtin_object_size(),
then does an array access to check for NUL-termination. A quirk of
__builtin_object_size() is that for strings whose values are runtime
dependent, __builtin_object_size(str, 1 or 0) returns the maximum size
of possible values when those sizes are determinable at compile time.
Example:

  static const char *v = "FOO BAR";
  static const char *y = "FOO BA";
  unsigned long x (int z) {
      // Returns 8, which is:
      // max(__builtin_object_size(v, 1), __builtin_object_size(y, 1))
      return __builtin_object_size(z ? v : y, 1);
  }

So when FORTIFY_SOURCE is enabled, the current implementation of
__compiletime_strlen() will try to access beyond the end of y at runtime
using the size of v. Mixed with UBSAN_LOCAL_BOUNDS we get a fault.

hidinput_allocate() has a local C string whose value is control flow
dependent on a switch statement, so __builtin_object_size(str, 1)
evaluates to the maximum string length, making all other cases fault on
the last character check. hidinput_allocate() could be cleaned up to
avoid runtime calls to strlen() since the local variable can only have
literal values, so there's no benefit to trying to fortify the strlen
call site there.

Perform a __builtin_constant_p() check against index 0 earlier in the
macro to filter out the control-flow-dependant case. Add a KUnit test
for checking the expected behavioral characteristics of FORTIFY_SOURCE
internals.

Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Tom Rix <trix@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: "Steven Rostedt (Google)" <rostedt@goodmis.org>
Cc: David Gow <davidgow@google.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Sander Vanheule <sander@svanheule.net>
Cc: linux-hardening@vger.kernel.org
Cc: llvm@lists.linux.dev
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Android Treehugger Robot
Link: https://android-review.googlesource.com/c/kernel/common/+/2206839Co-developed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

One of the "legitimate" uses of strncpy() is copying a NUL-terminated
string into a fixed-size non-NUL-terminated character array. To avoid
the weaknesses and ambiguity of intent when using strncpy(), provide
replacement functions that explicitly distinguish between trailing
padding and not, and require the destination buffer size be discoverable
by the compiler.

For example:

struct obj {
	int foo;
	char small[4] __nonstring;
	char big[8] __nonstring;
	int bar;
};

struct obj p;

/* This will truncate to 4 chars with no trailing NUL */
strncpy(p.small, "hello", sizeof(p.small));
/* p.small contains 'h', 'e', 'l', 'l' */

/* This will NUL pad to 8 chars. */
strncpy(p.big, "hello", sizeof(p.big));
/* p.big contains 'h', 'e', 'l', 'l', 'o', '\0', '\0', '\0' */

When the "__nonstring" attributes are missing, the intent of the
programmer becomes ambiguous for whether the lack of a trailing NUL
in the p.small copy is a bug. Additionally, it's not clear whether
the trailing padding in the p.big copy is _needed_. Both cases
become unambiguous with:

strtomem(p.small, "hello");
strtomem_pad(p.big, "hello", 0);

See also https://github.com/KSPP/linux/issues/90

Expand the memcpy KUnit tests to include these functions.

Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Kees Cook <keescook@chromium.org>

Under some pathological 32-bit configs, the shift overflow KUnit tests
create huge stack frames. Split up the function to avoid this,
separating by rough shift overflow cases.

Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: Vitor Massaru Iha <vitor@massaru.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/202208301850.iuv9VwA8-lkp@intel.comAcked-by: Daniel Latypov <dlatypov@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

When the check_[op]_overflow() helpers were introduced, all arguments
were required to be the same type to make the fallback macros simpler.
However, now that the fallback macros have been removed[1], it is fine
to allow mixed types, which makes using the helpers much more useful,
as they can be used to test for type-based overflows (e.g. adding two
large ints but storing into a u8), as would be handy in the drm core[2].

Remove the restriction, and add additional self-tests that exercise
some of the mixed-type overflow cases, and double-check for accidental
macro side-effects.

[1] https://git.kernel.org/linus/4eb6bd55cfb22ffc20652732340c4962f3ac9a91
[2] https://lore.kernel.org/lkml/20220824084514.2261614-2-gwan-gyeong.mun@intel.com

Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: linux-hardening@vger.kernel.org
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Tested-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

There are two definitions of the is_signed_type() macro: one in
<linux/overflow.h> and a second definition in <linux/trace_events.h>.

As suggested by Linus Torvalds, move the definition of the
is_signed_type() macro into the <linux/compiler.h> header file. Change
the definition of the is_signed_type() macro to make sure that it does
not trigger any sparse warnings with future versions of sparse for
bitwise types. See also:
https://lore.kernel.org/all/CAHk-=whjH6p+qzwUdx5SOVVHjS3WvzJQr6mDUwhEyTf6pJWzaQ@mail.gmail.com/
https://lore.kernel.org/all/CAHk-=wjQGnVfb4jehFR0XyZikdQvCZouE96xR_nnf5kqaM5qqQ@mail.gmail.com/

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Isabella Basso <isabbasso@riseup.net>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sander Vanheule <sander@svanheule.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220826162116.1050972-3-bvanassche@acm.org

Although not documented, is_signed_type() must support the 'bool' and
pointer types next to scalar and enumeration types. Add a selftest that
verifies that this macro handles all supported types correctly.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Isabella Basso <isabbasso@riseup.net>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sander Vanheule <sander@svanheule.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Isabella Basso <isabbasso@riseup.net>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220826162116.1050972-2-bvanassche@acm.org

Pull irq fixes from Ingo Molnar:
 "Misc irqchip fixes: LoongArch driver fixes and a Hyper-V IOMMU fix"

* tag 'irq-urgent-2022-08-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/loongson-liointc: Fix an error handling path in liointc_init()
  irqchip/loongarch: Fix irq_domain_alloc_fwnode() abuse
  irqchip/loongson-pch-pic: Move find_pch_pic() into CONFIG_ACPI
  irqchip/loongson-eiointc: Fix a build warning
  irqchip/loongson-eiointc: Fix irq affinity setting
  iommu/hyper-v: Use helper instead of directly accessing affinity

Pull x86 kprobes fix from Ingo Molnar:
 "Fix a kprobes bug in JNG/JNLE emulation when a kprobe is installed at
  such instructions, possibly resulting in incorrect execution (the
  wrong branch taken)"

* tag 'perf-urgent-2022-08-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kprobes: Fix JNG/JNLE emulation

Pull tracing fixes from Steven Rostedt:
 "Various fixes for tracing:

   - Fix a return value of traceprobe_parse_event_name()

   - Fix NULL pointer dereference from failed ftrace enabling

   - Fix NULL pointer dereference when asking for registers from eprobes

   - Make eprobes consistent with kprobes/uprobes, filters and
     histograms"

* tag 'trace-v6.0-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Have filter accept "common_cpu" to be consistent
  tracing/probes: Have kprobes and uprobes use $COMM too
  tracing/eprobes: Have event probes be consistent with kprobes and uprobes
  tracing/eprobes: Fix reading of string fields
  tracing/eprobes: Do not hardcode $comm as a string
  tracing/eprobes: Do not allow eprobes to use $stack, or % for regs
  ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead
  tracing/perf: Fix double put of trace event when init fails
  tracing: React to error return from traceprobe_parse_event_name()

Make filtering consistent with histograms. As "cpu" can be a field of an
event, allow for "common_cpu" to keep it from being confused with the
"cpu" field of the event.

Link: https://lkml.kernel.org/r/20220820134401.513062765@goodmis.org
Link: https://lore.kernel.org/all/20220820220920.e42fa32b70505b1904f0a0ad@kernel.org/

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 1e3bac71 ("tracing/histogram: Rename "cpu" to "common_cpu"")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Both $comm and $COMM can be used to get current->comm in eprobes and the
filtering and histogram logic. Make kprobes and uprobes consistent in this
regard and allow both $comm and $COMM as well. Currently kprobes and
uprobes only handle $comm, which is inconsistent with the other utilities,
and can be confusing to users.

Link: https://lkml.kernel.org/r/20220820134401.317014913@goodmis.org
Link: https://lore.kernel.org/all/20220820220442.776e1ddaf8836e82edb34d01@kernel.org/

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 53305928 ("tracing: probeevent: Introduce new argument fetching code")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Currently, if a symbol "@" is attempted to be used with an event probe
(eprobes), it will cause a NULL pointer dereference crash.

Both kprobes and uprobes can reference data other than the main registers.
Such as immediate address, symbols and the current task name. Have eprobes
do the same thing.

For "comm", if "comm" is used and the event being attached to does not
have the "comm" field, then make it the "$comm" that kprobes has. This is
consistent to the way histograms and filters work.

Link: https://lkml.kernel.org/r/20220820134401.136924220@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 7491e2c4 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Currently when an event probe (eprobe) hooks to a string field, it does
not display it as a string, but instead as a number. This makes the field
rather useless. Handle the different kinds of strings, dynamic, static,
relational/dynamic etc.

Now when a string field is used, the ":string" type can be used to display
it:

  echo "e:sw sched/sched_switch comm=$next_comm:string" > dynamic_events

Link: https://lkml.kernel.org/r/20220820134400.959640191@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 7491e2c4 ("tracing: Add a probe that attaches to trace events")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

The variable $comm is hard coded as a string, which is true for both
kprobes and uprobes, but for event probes (eprobes) it is a field name. In
most cases the "comm" field would be a string, but there's no guarantee of
that fact.

Do not assume that comm is a string. Not to mention, it currently forces
comm fields to fault, as string processing for event probes is currently
broken.

Link: https://lkml.kernel.org/r/20220820134400.756152112@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 7491e2c4 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

While playing with event probes (eprobes), I tried to see what would
happen if I attempted to retrieve the instruction pointer (%rip) knowing
that event probes do not use pt_regs. The result was:

 BUG: kernel NULL pointer dereference, address: 0000000000000024
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 1 PID: 1847 Comm: trace-cmd Not tainted 5.19.0-rc5-test+ #309
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01
v03.03 07/14/2016
 RIP: 0010:get_event_field.isra.0+0x0/0x50
 Code: ff 48 c7 c7 c0 8f 74 a1 e8 3d 8b f5 ff e8 88 09 f6 ff 4c 89 e7 e8
50 6a 13 00 48 89 ef 5b 5d 41 5c 41 5d e9 42 6a 13 00 66 90 <48> 63 47 24
8b 57 2c 48 01 c6 8b 47 28 83 f8 02 74 0e 83 f8 04 74
 RSP: 0018:ffff916c394bbaf0 EFLAGS: 00010086
 RAX: ffff916c854041d8 RBX: ffff916c8d9fbf50 RCX: ffff916c255d2000
 RDX: 0000000000000000 RSI: ffff916c255d2008 RDI: 0000000000000000
 RBP: 0000000000000000 R08: ffff916c3a2a0c08 R09: ffff916c394bbda8
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff916c854041d8
 R13: ffff916c854041b0 R14: 0000000000000000 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff916c9ea40000(0000)
knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000024 CR3: 000000011b60a002 CR4: 00000000001706e0
 Call Trace:
  <TASK>
  get_eprobe_size+0xb4/0x640
  ? __mod_node_page_state+0x72/0xc0
  __eprobe_trace_func+0x59/0x1a0
  ? __mod_lruvec_page_state+0xaa/0x1b0
  ? page_remove_file_rmap+0x14/0x230
  ? page_remove_rmap+0xda/0x170
  event_triggers_call+0x52/0xe0
  trace_event_buffer_commit+0x18f/0x240
  trace_event_raw_event_sched_wakeup_template+0x7a/0xb0
  try_to_wake_up+0x260/0x4c0
  __wake_up_common+0x80/0x180
  __wake_up_common_lock+0x7c/0xc0
  do_notify_parent+0x1c9/0x2a0
  exit_notify+0x1a9/0x220
  do_exit+0x2ba/0x450
  do_group_exit+0x2d/0x90
  __x64_sys_exit_group+0x14/0x20
  do_syscall_64+0x3b/0x90
  entry_SYSCALL_64_after_hwframe+0x46/0xb0

Obviously this is not the desired result.

Move the testing for TPARG_FL_TPOINT which is only used for event probes
to the top of the "$" variable check, as all the other variables are not
used for event probes. Also add a check in the register parsing "%" to
fail if an event probe is used.

Link: https://lkml.kernel.org/r/20220820134400.564426983@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 7491e2c4 ("tracing: Add a probe that attaches to trace events")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

ftrace_startup does not remove ops from ftrace_ops_list when
ftrace_startup_enable fails:

register_ftrace_function
  ftrace_startup
    __register_ftrace_function
      ...
      add_ftrace_ops(&ftrace_ops_list, ops)
      ...
    ...
    ftrace_startup_enable // if ftrace failed to modify, ftrace_disabled is set to 1
    ...
  return 0 // ops is in the ftrace_ops_list.

When ftrace_disabled = 1, unregister_ftrace_function simply returns without doing anything:
unregister_ftrace_function
  ftrace_shutdown
    if (unlikely(ftrace_disabled))
            return -ENODEV;  // return here, __unregister_ftrace_function is not executed,
                             // as a result, ops is still in the ftrace_ops_list
    __unregister_ftrace_function
    ...

If ops is dynamically allocated, it will be free later, in this case,
is_ftrace_trampoline accesses NULL pointer:

is_ftrace_trampoline
  ftrace_ops_trampoline
    do_for_each_ftrace_op(op, ftrace_ops_list) // OOPS! op may be NULL!

Syzkaller reports as follows:
[ 1203.506103] BUG: kernel NULL pointer dereference, address: 000000000000010b
[ 1203.508039] #PF: supervisor read access in kernel mode
[ 1203.508798] #PF: error_code(0x0000) - not-present page
[ 1203.509558] PGD 800000011660b067 P4D 800000011660b067 PUD 130fb8067 PMD 0
[ 1203.510560] Oops: 0000 [#1] SMP KASAN PTI
[ 1203.511189] CPU: 6 PID: 29532 Comm: syz-executor.2 Tainted: G    B   W         5.10.0 #8
[ 1203.512324] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 1203.513895] RIP: 0010:is_ftrace_trampoline+0x26/0xb0
[ 1203.514644] Code: ff eb d3 90 41 55 41 54 49 89 fc 55 53 e8 f2 00 fd ff 48 8b 1d 3b 35 5d 03 e8 e6 00 fd ff 48 8d bb 90 00 00 00 e8 2a 81 26 00 <48> 8b ab 90 00 00 00 48 85 ed 74 1d e8 c9 00 fd ff 48 8d bb 98 00
[ 1203.518838] RSP: 0018:ffffc900012cf960 EFLAGS: 00010246
[ 1203.520092] RAX: 0000000000000000 RBX: 000000000000007b RCX: ffffffff8a331866
[ 1203.521469] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000010b
[ 1203.522583] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8df18b07
[ 1203.523550] R10: fffffbfff1be3160 R11: 0000000000000001 R12: 0000000000478399
[ 1203.524596] R13: 0000000000000000 R14: ffff888145088000 R15: 0000000000000008
[ 1203.525634] FS:  00007f429f5f4700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
[ 1203.526801] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1203.527626] CR2: 000000000000010b CR3: 0000000170e1e001 CR4: 00000000003706e0
[ 1203.528611] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1203.529605] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Therefore, when ftrace_startup_enable fails, we need to rollback registration
process and remove ops from ftrace_ops_list.

Link: https://lkml.kernel.org/r/20220818032659.56209-1-yangjihong1@huawei.comSuggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

If in perf_trace_event_init(), the perf_trace_event_open() fails, then it
will call perf_trace_event_unreg() which will not only unregister the perf
trace event, but will also call the put() function of the tp_event.

The problem here is that the trace_event_try_get_ref() is called by the
caller of perf_trace_event_init() and if perf_trace_event_init() returns a
failure, it will then call trace_event_put(). But since the
perf_trace_event_unreg() already called the trace_event_put() function, it
triggers a WARN_ON().

 WARNING: CPU: 1 PID: 30309 at kernel/trace/trace_dynevent.c:46 trace_event_dyn_put_ref+0x15/0x20

If perf_trace_event_reg() does not call the trace_event_try_get_ref() then
the perf_trace_event_unreg() should not be calling trace_event_put(). This
breaks symmetry and causes bugs like these.

Pull out the trace_event_put() from perf_trace_event_unreg() and call it
in the locations that perf_trace_event_unreg() is called. This not only
fixes this bug, but also brings back the proper symmetry of the reg/unreg
vs get/put logic.

Link: https://lore.kernel.org/all/cover.1660347763.git.kjlx@templeofstupid.com/
Link: https://lkml.kernel.org/r/20220816192817.43d5e17f@gandalf.local.home

Cc: stable@vger.kernel.org
Fixes: 1d18538e ("tracing: Have dynamic events have a ref counter")
Reported-by: Krister Johansen <kjlx@templeofstupid.com>
Reviewed-by: Krister Johansen <kjlx@templeofstupid.com>
Tested-by: Krister Johansen <kjlx@templeofstupid.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

The function traceprobe_parse_event_name() may set the first two function
arguments to a non-null value and still return -EINVAL to indicate an
unsuccessful completion of the function. Hence, it is not sufficient to
just check the result of the two function arguments for being not null,
but the return value also needs to be checked.

Commit 95c104c3 ("tracing: Auto generate event name when creating a
group of events") changed the error-return-value checking of the second
traceprobe_parse_event_name() invocation in __trace_eprobe_create() and
removed checking the return value to jump to the error handling case.

Reinstate using the return value in the error-return-value checking.

Link: https://lkml.kernel.org/r/20220811071734.20700-1-lukas.bulwahn@gmail.com

Fixes: 95c104c3 ("tracing: Auto generate event name when creating a group of events")
Acked-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Pull i2c fixes from Wolfram Sang:
 "A revert to fix a regression introduced this merge window and a fix
  for proper error handling in the remove path of the iMX driver"

* tag 'i2c-for-6.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: imx: Make sure to unregister adapter on remove()
  Revert "i2c: scmi: Replace open coded device_get_match_data()"

Pull cifs client fixes from Steve French:

 - memory leak fix

 - two small cleanups

 - trivial strlcpy removal

 - update missing entry for cifs headers in MAINTAINERS file

* tag '6.0-rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: move from strlcpy with unused retval to strscpy
  cifs: Fix memory leak on the deferred close
  cifs: remove useless parameter 'is_fsctl' from SMB2_ioctl()
  cifs: remove unused server parameter from calc_smb_size()
  cifs: missing directory in MAINTAINERS file

GCC has supported asm goto since 4.5, and Clang has since version 9.0.0.
The minimum supported versions of these tools for the build according to
Documentation/process/changes.rst are 5.1 and 11.0.0 respectively.

Remove the feature detection script, Kconfig option, and clean up some
fallback code that is no longer supported.

The removed script was also testing for a GCC specific bug that was
fixed in the 4.7 release.

Also remove workarounds for bpftrace using clang older than 9.0.0, since
other BPF backend fixes are required at this point.

Link: https://lore.kernel.org/lkml/CAK7LNATSr=BXKfkdW8f-H5VT_w=xBpT2ZQcZ7rm6JfkdE+QnmA@mail.gmail.com/
Link: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637Acked-by: Borislav Petkov <bp@suse.de>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If for whatever reasons pm_runtime_resume_and_get() fails and .remove() is
exited early, the i2c adapter stays around and the irq still calls its
handler, while the driver data and the register mapping go away. So if
later the i2c adapter is accessed or the irq triggers this results in
havoc accessing freed memory and unmapped registers.

So unregister the software resources even if resume failed, and only skip
the hardware access in that case.

Fixes: 588eb93e ("i2c: imx: add runtime pm support to improve the performance")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

This reverts commit 9ae551de. We got a
regression report, so ensure this machine boots again. We will come back
with a better version hopefully.
Reported-by: Josef Johansson <josef@oderland.se>
Link: https://lore.kernel.org/r/4d2d5b04-0b6c-1cb1-a63f-dc06dfe1b5da@oderland.seSigned-off-by: Wolfram Sang <wsa@kernel.org>

Merge tag 'kbuild-fixes-v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Fix module versioning broken on some architectures

 - Make dummy-tools enable CONFIG_PPC_LONG_DOUBLE_128

 - Remove -Wformat-zero-length, which has no warning instance

 - Fix the order between drivers and libs in modules.order

 - Fix false-positive warnings in clang-analyzer

* tag 'kbuild-fixes-v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  scripts/clang-tools: Remove DeprecatedOrUnsafeBufferHandling check
  kbuild: fix the modules order between drivers and libs
  scripts/Makefile.extrawarn: Do not disable clang's -Wformat-zero-length
  kbuild: dummy-tools: pretend we understand __LONG_DOUBLE_128__
  modpost: fix module versioning when a symbol lacks valid CRC

Merge tag 'perf-tools-fixes-for-v6.0-2022-08-19' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Fix alignment for cpu map masks in event encoding.

 - Support reading PERF_FORMAT_LOST, perf tool counterpart for a feature
   that was added in this merge window.

 - Sync perf tools copies of kernel headers: socket, msr-index, fscrypt,
   cpufeatures, i915_drm, kvm, vhost, perf_event.

* tag 'perf-tools-fixes-for-v6.0-2022-08-19' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  perf tools: Support reading PERF_FORMAT_LOST
  libperf: Add a test case for read formats
  libperf: Handle read format in perf_evsel__read()
  tools headers UAPI: Sync linux/perf_event.h with the kernel sources
  tools headers UAPI: Sync x86's asm/kvm.h with the kernel sources
  tools headers UAPI: Sync KVM's vmx.h header with the kernel sources
  tools include UAPI: Sync linux/vhost.h with the kernel sources
  tools headers kvm s390: Sync headers with the kernel sources
  tools headers UAPI: Sync linux/kvm.h with the kernel sources
  tools headers UAPI: Sync drm/i915_drm.h with the kernel sources
  tools headers cpufeatures: Sync with the kernel sources
  tools headers UAPI: Sync linux/fscrypt.h with the kernel sources
  tools arch x86: Sync the msr-index.h copy with the kernel sources
  perf beauty: Update copy of linux/socket.h with the kernel sources
  perf cpumap: Fix alignment for masks in event encoding
  perf cpumap: Compute mask size in constant time
  perf cpumap: Synthetic events and const/static
  perf cpumap: Const map for max()

Pull s390 updates from Alexander Gordeev:

 - Fix a KVM crash on z12 and older machines caused by a wrong
   assumption that Query AP Configuration Information is always
   available.

 - Lower severity of excessive Hypervisor filesystem error messages
   when booting under KVM.

* tag 's390-6.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/ap: fix crash on older machines based on QCI info missing
  s390/hypfs: avoid error message under KVM

Pull powerpc fixes from Michael Ellerman:

 - Fix atomic sleep warnings at boot due to get_phb_number() taking a
   mutex with a spinlock held on some machines.

 - Add missing PMU selftests to .gitignores.

Thanks to Guenter Roeck and Russell Currey.

* tag 'powerpc-6.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  selftests/powerpc: Add missing PMU selftests to .gitignores
  powerpc/pci: Fix get_phb_number() locking

Pull rdma fixes from Jason Gunthorpe:
 "A few minor fixes:

   - Fix buffer management in SRP to correct a regression with the login
     authentication feature from v5.17

   - Don't iterate over non-present ports in mlx5

   - Fix an error introduced by the foritify work in cxgb4

   - Two bug fixes for the recently merged ERDMA driver

   - Unbreak RDMA dmabuf support, a regresion from v5.19"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  RDMA: Handle the return code from dma_resv_wait_timeout() properly
  RDMA/erdma: Correct the max_qp and max_cq capacities of the device
  RDMA/erdma: Using the key in FMR WR instead of MR structure
  RDMA/cxgb4: fix accept failure due to increased cpl_t5_pass_accept_rpl size
  RDMA/mlx5: Use the proper number of ports
  IB/iser: Fix login with authentication

This `clang-analyzer` check flags the use of memset(), suggesting a more
secure version of the API, such as memset_s(), which does not exist in
the kernel:

  warning: Call to function 'memset' is insecure as it does not provide
  security checks introduced in the C11 standard. Replace with analogous
  functions that support length arguments or provides boundary checks such
  as 'memset_s' in case of C11
  [clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling]
Signed-off-by: Guru Das Srinagesh <quic_gurus@quicinc.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Commit b2c88554 ("kbuild: update modules.order only when contained
modules are updated") accidentally changed the modules order.

Prior to that commit, the modules order was determined based on
vmlinux-dirs, which lists core-y/m, drivers-y/m, libs-y/m, in this order.

Now, subdir-modorder lists them in a different order: core-y/m, libs-y/m,
drivers-y/m.

Presumably, there was no practical issue because the modules in drivers
and libs are orthogonal, but there is no reason to have this distortion.

Get back to the original order.

Fixes: b2c88554 ("kbuild: update modules.order only when contained modules are updated")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

There are no instances of this warning in the tree across several
difference architectures and configurations. This was added by
commit 26ea6bb1 ("kbuild, LLVMLinux: Supress warnings unless W=1-3")
back in 2014, where it might have been necessary, but there are no
instances of it now so stop disabling it to increase warning coverage
for clang.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

There is a test in powerpc's Kconfig which checks __LONG_DOUBLE_128__
and sets CONFIG_PPC_LONG_DOUBLE_128 if it is understood by the compiler.

We currently don't handle it, so this results in PPC_LONG_DOUBLE_128 not
being in super-config generated by dummy-tools. So take this into
account in the gcc script and preprocess __LONG_DOUBLE_128__ as "1".
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Since commit 7b453719 ("kbuild: link symbol CRCs at final link,
removing CONFIG_MODULE_REL_CRCS"), module versioning is broken on
some architectures. Loading a module fails with "disagrees about
version of symbol module_layout".

On such architectures (e.g. ARCH=sparc build with sparc64_defconfig),
modpost shows a warning, like follows:

  WARNING: modpost: EXPORT symbol "_mcount" [vmlinux] version generation failed, symbol will not be versioned.
  Is "_mcount" prototyped in <asm/asm-prototypes.h>?

Previously, it was a harmless warning (CRC check was just skipped),
but now wrong CRCs are used for comparison because invalid CRCs are
just skipped.

  $ sparc64-linux-gnu-nm -n vmlinux
    [snip]
  0000000000c2cea0 r __ksymtab__kstrtol
  0000000000c2ceb8 r __ksymtab__kstrtoul
  0000000000c2ced0 r __ksymtab__local_bh_enable
  0000000000c2cee8 r __ksymtab__mcount
  0000000000c2cf00 r __ksymtab__printk
  0000000000c2cf18 r __ksymtab__raw_read_lock
  0000000000c2cf30 r __ksymtab__raw_read_lock_bh
    [snip]
  0000000000c53b34 D __crc__kstrtol
  0000000000c53b38 D __crc__kstrtoul
  0000000000c53b3c D __crc__local_bh_enable
  0000000000c53b40 D __crc__printk
  0000000000c53b44 D __crc__raw_read_lock
  0000000000c53b48 D __crc__raw_read_lock_bh

Please notice __crc__mcount is missing here.

When the module subsystem looks up a CRC that comes after, it results
in reading out a wrong address. For example, when __crc__printk is
needed, the module subsystem reads 0xc53b44 instead of 0xc53b40.

All CRC entries must be output for correct index accessing. Invalid
CRCs will be unused, but are needed to keep the one-to-one mapping
between __ksymtab_* and __crc_*.

The best is to fix all modpost warnings, but several warnings are still
remaining on less popular architectures.

Fixes: 7b453719 ("kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS")
Reported-by: matoro <matoro_mailinglist_kernel@matoro.tk>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: matoro <matoro_mailinglist_kernel@matoro.tk>

Pull block fixes from Jens Axboe:
 "A few fixes that should go into this release:

   - Small series of patches for ublk (ZiyangZhang)

   - Remove dead function (Yu)

   - Fix for running a block queue in case of resource starvation
     (Yufen)"

* tag 'block-6.0-2022-08-19' of git://git.kernel.dk/linux-block:
  blk-mq: run queue no matter whether the request is the last request
  blk-mq: remove unused function blk_mq_queue_stopped()
  ublk_drv: do not add a re-issued request aborted previously to ioucmd's task_work
  ublk_drv: update comment for __ublk_fail_req()
  ublk_drv: check ubq_daemon_is_dying() in __ublk_rq_task_work()
  ublk_drv: update iod->addr for UBLK_IO_NEED_GET_DATA