linux.git/tools, branch v5.4.219

perf tools: Fixup get_current_dir_name() compilation

2022-10-15T05:54:36+00:00

commit 128dbd78bd673f9edbc4413072b23efb6657feb0 upstream.

strdup() prototype doesn't live in stdlib.h .

Add limits.h for PATH_MAX definition as well.

This fixes the build on Android.

Signed-off-by: Alexey Dobriyan (SK hynix) 
Acked-by: Namhyung Kim 
Link: http://lore.kernel.org/lkml/YRukaQbrgDWhiwGr@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Florian Fainelli 
Signed-off-by: Greg Kroah-Hartman

x86/speculation: Add RSB VM Exit protections

2022-10-07T07:16:56+00:00

commit 2b1299322016731d56807aa49254a5ea3080b6b3 upstream.

tl;dr: The Enhanced IBRS mitigation for Spectre v2 does not work as
documented for RET instructions after VM exits. Mitigate it with a new
one-entry RSB stuffing mechanism and a new LFENCE.

== Background ==

Indirect Branch Restricted Speculation (IBRS) was designed to help
mitigate Branch Target Injection and Speculative Store Bypass, i.e.
Spectre, attacks. IBRS prevents software run in less privileged modes
from affecting branch prediction in more privileged modes. IBRS requires
the MSR to be written on every privilege level change.

To overcome some of the performance issues of IBRS, Enhanced IBRS was
introduced.  eIBRS is an "always on" IBRS, in other words, just turn
it on once instead of writing the MSR on every privilege level change.
When eIBRS is enabled, more privileged modes should be protected from
less privileged modes, including protecting VMMs from guests.

== Problem ==

Here's a simplification of how guests are run on Linux' KVM:

void run_kvm_guest(void)
{
	// Prepare to run guest
	VMRESUME();
	// Clean up after guest runs
}

The execution flow for that would look something like this to the
processor:

1. Host-side: call run_kvm_guest()
2. Host-side: VMRESUME
3. Guest runs, does "CALL guest_function"
4. VM exit, host runs again
5. Host might make some "cleanup" function calls
6. Host-side: RET from run_kvm_guest()

Now, when back on the host, there are a couple of possible scenarios of
post-guest activity the host needs to do before executing host code:

* on pre-eIBRS hardware (legacy IBRS, or nothing at all), the RSB is not
touched and Linux has to do a 32-entry stuffing.

* on eIBRS hardware, VM exit with IBRS enabled, or restoring the host
IBRS=1 shortly after VM exit, has a documented side effect of flushing
the RSB except in this PBRSB situation where the software needs to stuff
the last RSB entry "by hand".

IOW, with eIBRS supported, host RET instructions should no longer be
influenced by guest behavior after the host retires a single CALL
instruction.

However, if the RET instructions are "unbalanced" with CALLs after a VM
exit as is the RET in #6, it might speculatively use the address for the
instruction after the CALL in #3 as an RSB prediction. This is a problem
since the (untrusted) guest controls this address.

Balanced CALL/RET instruction pairs such as in step #5 are not affected.

== Solution ==

The PBRSB issue affects a wide variety of Intel processors which
support eIBRS. But not all of them need mitigation. Today,
X86_FEATURE_RSB_VMEXIT triggers an RSB filling sequence that mitigates
PBRSB. Systems setting RSB_VMEXIT need no further mitigation - i.e.,
eIBRS systems which enable legacy IBRS explicitly.

However, such systems (X86_FEATURE_IBRS_ENHANCED) do not set RSB_VMEXIT
and most of them need a new mitigation.

Therefore, introduce a new feature flag X86_FEATURE_RSB_VMEXIT_LITE
which triggers a lighter-weight PBRSB mitigation versus RSB_VMEXIT.

The lighter-weight mitigation performs a CALL instruction which is
immediately followed by a speculative execution barrier (INT3). This
steers speculative execution to the barrier -- just like a retpoline
-- which ensures that speculation can never reach an unbalanced RET.
Then, ensure this CALL is retired before continuing execution with an
LFENCE.

In other words, the window of exposure is opened at VM exit where RET
behavior is troublesome. While the window is open, force RSB predictions
sampling for RET targets to a dead end at the INT3. Close the window
with the LFENCE.

There is a subset of eIBRS systems which are not vulnerable to PBRSB.
Add these systems to the cpu_vuln_whitelist[] as NO_EIBRS_PBRSB.
Future systems that aren't vulnerable will set ARCH_CAP_PBRSB_NO.

  [ bp: Massage, incorporate review comments from Andy Cooper. ]

Signed-off-by: Daniel Sneddon 
Co-developed-by: Pawan Gupta 
Signed-off-by: Pawan Gupta 
Signed-off-by: Borislav Petkov 
[cascardo: no intra-function validation]
Signed-off-by: Thadeu Lima de Souza Cascardo 
Signed-off-by: Greg Kroah-Hartman

Revert "x86/speculation: Add RSB VM Exit protections"

2022-10-07T07:16:54+00:00

This reverts commit f2f41ef0352db9679bfae250d7a44b3113f3a3cc.

This is commit 2b1299322016731d56807aa49254a5ea3080b6b3 upstream.

In order to apply IBRS mitigation for Retbleed, PBRSB mitigations must be
reverted and the reapplied, so the backports can look sane.

Signed-off-by: Thadeu Lima de Souza Cascardo 
Signed-off-by: Greg Kroah-Hartman

selftests: Fix the if conditions of in test_extra_filter()

2022-10-05T08:37:45+00:00

[ Upstream commit bc7a319844891746135dc1f34ab9df78d636a3ac ]

The socket 2 bind the addr in use, bind should fail with EADDRINUSE. So
if bind success or errno != EADDRINUSE, testcase should be failed.

Fixes: 3ca8e4029969 ("soreuseport: BPF selection functional test")
Signed-off-by: Wang Yufen 
Link: https://lore.kernel.org/r/1663916557-10730-1-git-send-email-wangyufen@huawei.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

perf kcore_copy: Do not check /proc/modules is unchanged

2022-09-28T09:04:07+00:00

[ Upstream commit 5b427df27b94aec1312cace48a746782a0925c53 ]

/proc/kallsyms and /proc/modules are compared before and after the copy
in order to ensure no changes during the copy.

However /proc/modules also might change due to reference counts changing
even though that does not make any difference.

Any modules loaded or unloaded should be visible in changes to kallsyms,
so it is not necessary to check /proc/modules also anyway.

Remove the comparison checking that /proc/modules is unchanged.

Fixes: fc1b691d7651d949 ("perf buildid-cache: Add ability to add kcore to the cache")
Reported-by: Daniel Dao 
Signed-off-by: Adrian Hunter 
Tested-by: Daniel Dao 
Acked-by: Namhyung Kim 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Link: https://lore.kernel.org/r/20220914122429.8770-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf jit: Include program header in ELF files

2022-09-28T09:04:07+00:00

[ Upstream commit babd04386b1df8c364cdaa39ac0e54349502e1e5 ]

The missing header makes it hard for programs like elfutils to open
these files.

Fixes: 2d86612aacb7805f ("perf symbol: Correct address for bss symbols")
Reviewed-by: Leo Yan 
Signed-off-by: Lieven Hey 
Tested-by: Leo Yan 
Cc: Leo Yan 
Link: https://lore.kernel.org/r/20220915092910.711036-1-lieven.hey@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

Revert "selftests/bpf: Fix test_align verifier log patterns"

2022-09-05T08:27:39+00:00

This partially reverts commit 6a9b3f0f3bad4ca6421f8c20e1dde9839699db0f.
The upstream commit addresses multiple verifier changes, only one of
which was backported to v5.4. Therefore only keep the relevant changes
and revert the others.

Signed-off-by: Jean-Philippe Brucker 
Signed-off-by: Greg Kroah-Hartman

Revert "selftests/bpf: Fix "dubious pointer arithmetic" test"

2022-09-05T08:27:39+00:00

This reverts commit 6098562ed9df1babcc0ba5b89c4fb47715ba3f72.
It shouldn't be in v5.4 because the commit it fixes is only present in
v5.9 onward.

Signed-off-by: Jean-Philippe Brucker 
Signed-off-by: Greg Kroah-Hartman

selftests/kprobe: Do not test for GRP/ without event failures

2022-08-25T09:18:34+00:00

[ Upstream commit f5eab65ff2b76449286d18efc7fee3e0b72f7d9b ]

A new feature is added where kprobes (and other probes) do not need to
explicitly state the event name when creating a probe. The event name will
come from what is being attached.

That is:

  # echo 'p:foo/ vfs_read' > kprobe_events

Will no longer error, but instead create an event:

  # cat kprobe_events
 p:foo/p_vfs_read_0 vfs_read

This should not be tested as an error case anymore. Remove it from the
selftest as now this feature "breaks" the selftest as it no longer fails
as expected.

Link: https://lore.kernel.org/all/1656296348-16111-1-git-send-email-quic_linyyuan@quicinc.com/
Link: https://lkml.kernel.org/r/20220712161707.6dc08a14@gandalf.local.home

Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Sasha Levin

tools build: Switch to new openssl API for test-libcrypto

2022-08-25T09:18:25+00:00

commit 5b245985a6de5ac18b5088c37068816d413fb8ed upstream.

Switch to new EVP API for detecting libcrypto, as Fedora 36 returns an
error when it encounters the deprecated function MD5_Init() and the others.

The error would be interpreted as missing libcrypto, while in reality it is
not.

Fixes: 6e8ccb4f624a73c5 ("tools/bpf: properly account for libbfd variations")
Signed-off-by: Roberto Sassu 
Cc: Alexei Starovoitov 
Cc: Andrii Nakryiko 
Cc: bpf@vger.kernel.org
Cc: Daniel Borkmann 
Cc: Ingo Molnar 
Cc: John Fastabend 
Cc: KP Singh 
Cc: llvm@lists.linux.dev
Cc: Martin KaFai Lau 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Nick Terrell 
Cc: Peter Zijlstra 
Cc: Quentin Monnet 
Cc: Song Liu 
Cc: Stanislav Fomichev 
Link: https://lore.kernel.org/r/20220719170555.2576993-4-roberto.sassu@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman