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@sipa sipa commented Nov 19, 2019

This fixes #17523.

The code to determine which CPUID subleaves to explore was incorrect in #17270. The new code here is based on Intel's reference documentation for CPUID (a document called "Intel® Processor Identification and the CPUID Instruction - Application Note 485", which I cannot actually find on their own website).

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mb300sd commented Nov 19, 2019

Tested. Changes fixed the issue for me.

@sipa sipa added the Bug label Nov 19, 2019
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Tested ba2c5fe by building, running tests and bitcoind. I was unaffected by the issue but running bitcoind appears unaffected by this change.

$ uname -a
Linux purity 4.19.0-5-amd64 #1 SMP Debian 4.19.37-5+deb10u2 (2019-08-08) x86_64 GNU/Linux

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laanwj commented Nov 20, 2019

Concept ACK. Thanks @mb300sd for catching this before a release.

@fanquake fanquake added this to the 0.20.0 milestone Nov 20, 2019
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laanwj commented Nov 22, 2019

ACK f93fc61

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ACK f93fc61 code review, tested rebased on current master bb862d7 with Debian 4.19 x86_64

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ACK f93fc61, reviewed code and compared with the intel doc, tested on an AMD and an Intel processor.

if (subleaf == 0) maxsub = ax;
if (subleaf == maxsub) break;
} else if (leaf == 11) {
if ((cx & 0xff00) == 0) break;
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Got slightly confused here because the intel pdf linked above recommends eax=0 and ebx=0 as break condition for leaf 11 (p.40), but checking cx & 0xff00 should be equivalent according to this.

laanwj added a commit that referenced this pull request Nov 24, 2019
f93fc61 Put bounds on the number of CPUID leaves explored (Pieter Wuille)
ba2c5fe Fix CPUID subleaf iteration (Pieter Wuille)

Pull request description:

  This fixes #17523.

  The code to determine which CPUID subleaves to explore was incorrect in #17270. The new code here is based on Intel's reference documentation for CPUID (a document called "Intel® Processor Identification and the CPUID Instruction - Application Note 485", which I cannot actually find on their own website).

ACKs for top commit:
  laanwj:
    ACK f93fc61
  jonatack:
    ACK f93fc61 code review, tested rebased on current master bb862d7 with Debian 4.19 x86_64
  mzumsande:
    ACK f93fc61, reviewed code and compared with the intel doc, tested on an AMD and an Intel processor.

Tree-SHA512: 2790b326fa397b736c0f39f25807bea57de2752fdd58bf6693d044b8cb26df36c11cce165a334b471f8e33724f10e3b76edab5cc4e0e7776601aabda13277245
@laanwj laanwj merged commit f93fc61 into bitcoin:master Nov 24, 2019
sidhujag pushed a commit to syscoin/syscoin that referenced this pull request Nov 24, 2019
f93fc61 Put bounds on the number of CPUID leaves explored (Pieter Wuille)
ba2c5fe Fix CPUID subleaf iteration (Pieter Wuille)

Pull request description:

  This fixes bitcoin#17523.

  The code to determine which CPUID subleaves to explore was incorrect in bitcoin#17270. The new code here is based on Intel's reference documentation for CPUID (a document called "Intel® Processor Identification and the CPUID Instruction - Application Note 485", which I cannot actually find on their own website).

ACKs for top commit:
  laanwj:
    ACK f93fc61
  jonatack:
    ACK f93fc61 code review, tested rebased on current master bb862d7 with Debian 4.19 x86_64
  mzumsande:
    ACK f93fc61, reviewed code and compared with the intel doc, tested on an AMD and an Intel processor.

Tree-SHA512: 2790b326fa397b736c0f39f25807bea57de2752fdd58bf6693d044b8cb26df36c11cce165a334b471f8e33724f10e3b76edab5cc4e0e7776601aabda13277245
deadalnix pushed a commit to Bitcoin-ABC/bitcoin-abc that referenced this pull request May 26, 2020
Summary:
```
The code to determine which CPUID subleaves to explore was incorrect in
#17270. The new code here is based on Intel's reference documentation
for CPUID (a document called "Intel® Processor Identification and the
CPUID Instruction - Application Note 485", which I cannot actually find
on their own website).
```

Backport of core [[bitcoin/bitcoin#17527 | PR17527]].

Test Plan:
  ninja all check-all

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Subscribers: deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D6254
sidhujag pushed a commit to syscoin-core/syscoin that referenced this pull request Nov 10, 2020
f93fc61 Put bounds on the number of CPUID leaves explored (Pieter Wuille)
ba2c5fe Fix CPUID subleaf iteration (Pieter Wuille)

Pull request description:

  This fixes bitcoin#17523.

  The code to determine which CPUID subleaves to explore was incorrect in bitcoin#17270. The new code here is based on Intel's reference documentation for CPUID (a document called "Intel® Processor Identification and the CPUID Instruction - Application Note 485", which I cannot actually find on their own website).

ACKs for top commit:
  laanwj:
    ACK f93fc61
  jonatack:
    ACK f93fc61 code review, tested rebased on current master bb862d7 with Debian 4.19 x86_64
  mzumsande:
    ACK f93fc61, reviewed code and compared with the intel doc, tested on an AMD and an Intel processor.

Tree-SHA512: 2790b326fa397b736c0f39f25807bea57de2752fdd58bf6693d044b8cb26df36c11cce165a334b471f8e33724f10e3b76edab5cc4e0e7776601aabda13277245
random-zebra added a commit to PIVX-Project/PIVX that referenced this pull request Apr 14, 2021
cecbf6c Use secure.h header for secure allocators (Fuzzbawls)
d9f67da net: add ifaddrs.h include (fanquake)
e906436 build: check if -lsocket is required with *ifaddrs (fanquake)
414f405 rand: only try and use freeifaddrs if available (fanquake)
3a039d6 build: avoid getifaddrs when unavailable (Cory Fields)
77bddd7 Use GetStrongRandBytes in gmp bignum initialization (Fuzzbawls)
b70b26f Fix typo in comment in randomenv.cpp (Fuzzbawls)
fec460c Put bounds on the number of CPUID leaves explored (Pieter Wuille)
41ab1ff Fix CPUID subleaf iteration (Pieter Wuille)
8a9bbb1 Move events_hasher into RNGState() (Pieter Wuille)
88c2ae5 random: mark RandAddPeriodic and SeedPeriodic as noexcept (fanquake)
81d382f doc: correct random.h docs after bitcoin#17270 (fanquake)
f363ea9 Seed RNG with precision timestamps on receipt of net messages. (Matt Corallo)
7d6ddcb Run background seeding periodically instead of unpredictably (Pieter Wuille)
4679181 Add information gathered through getauxval() (Pieter Wuille)
88d97d0 Feed CPUID data into RNG (Pieter Wuille)
8f5b9c9 Use sysctl for seeding on MacOS/BSD (Pieter Wuille)
67de246 Gather additional entropy from the environment (Pieter Wuille)
6142e1f Seed randomness with process id / thread id / various clocks (Pieter Wuille)
7bde8b7 [MOVEONLY] Move cpuid code from random to compat/cpuid (Fuzzbawls)
52b5336 [MOVEONLY] Move perfmon data gathering to new randomenv module (Pieter Wuille)
27cf995 doc: minor corrections in random.cpp (fanquake)
fccd2b8 doc: correct function name in ReportHardwareRand() (fanquake)
909473e Fix FreeBSD build by including utilstrencodings.h (Fuzzbawls)
630931f break circular dependency: random/sync -> util -> random/sync (Fuzzbawls)
5eed08c random: remove call to RAND_screen() (Windows only) (fanquake)
ada9868 gui: remove OpenSSL PRNG seeding (Windows, Qt only) (fanquake)
22a7121 Fix non-deterministic coverage of test DoS_mapOrphans (Fuzzbawls)
79e7fd3 Add ChaCha20 bench (Jonas Schnelli)
6966aa9 Add ChaCha20 encryption option (XOR) (Jonas Schnelli)
28c9cdb tests: Add script checking for deterministic line coverage (practicalswift)
c82e359 test: Make bloom tests deterministic (MarcoFalke)
7b33223 Document strenghtening (Pieter Wuille)
0190dec Add hash strengthening to the RNG (Pieter Wuille)
67e336d Use RdSeed when available, and reduce RdRand load (Pieter Wuille)
4ffda1f Document RNG design in random.h (Pieter Wuille)
2b6381e Use secure allocator for RNG state (Pieter Wuille)
080deb3 Encapsulate RNGState better (Pieter Wuille)
787d72f DRY: Implement GetRand using FastRandomContext::randrange (Pieter Wuille)
5bc2583 Sprinkle some sweet noexcepts over the RNG code (Pieter Wuille)
774899f Remove hwrand_initialized. (Pieter Wuille)
698d133 Switch all RNG code to the built-in PRNG. (Pieter Wuille)
038a45a Integrate util/system's CInit into RNGState (Fuzzbawls)
5f20e62 Abstract out seeding/extracting entropy into RNGState::MixExtract (Pieter Wuille)
298f97c Add thread safety annotations to RNG state (Pieter Wuille)
2326535 Rename some hardware RNG related functions (Pieter Wuille)
d76ee83 Automatically initialize RNG on first use. (Pieter Wuille)
1a5dbc5 Don't log RandAddSeedPerfmon details (Pieter Wuille)
32e6c42 Simplify testing RNG code (Fuzzbawls)
972effa Make unit tests use the insecure_rand_ctx exclusively (Fuzzbawls)
af52bf5 Use a FastRandomContext in LimitOrphanTxSize (Fuzzbawls)
746d466 Introduce a Shuffle for FastRandomContext and use it in wallet (Fuzzbawls)
1cdf124 Use a local FastRandomContext in a few more places in net (Fuzzbawls)
e862564 Make addrman use its local RNG exclusively (Fuzzbawls)
94b2ead Make FastRandomContext support standard C++11 RNG interface (Pieter Wuille)

Pull request description:

  This is a collection of upstream PRs that have been backported to bring our RNG (`src/random`) code more up-to-date. The following upstream PRs have been included here:

  - bitcoin#12742
  - bitcoin#14624
    - some of this had already been merged previously
  - bitcoin#14955
  - bitcoin#15250
  - bitcoin#15224
  - bitcoin#15324
  - bitcoin#15296
  - bitcoin#15512
  - bitcoin#16878
  - bitcoin#17151
  - bitcoin#17191
  - bitcoin#13236
  - bitcoin#13314
  - bitcoin#17169
  - bitcoin#17270
    -  omitted last commit as our testing framework doesn't support it currently
    - omitted bitcoin@64e1e02, to be pulled in after our time utility is updated in a separate PR
  - bitcoin#17573
  - bitcoin#17507
  - bitcoin#17670
  - bitcoin#17527
  - bitcoin#14127
  - bitcoin#21486

ACKs for top commit:
  furszy:
    ACK cecbf6c with a minor nit that can be easily tackled later.
  random-zebra:
    rebase utACK cecbf6c and merging...

Tree-SHA512: 3463b693cc9bddc1ec15228d264a794f5c2f159073fafa2ccf6e2563abfeb4369e49505f97ca84f2478ca792bd07b66d2cd83c58044d6a0cae6af42d22f5784b
@bitcoin bitcoin locked as resolved and limited conversation to collaborators Dec 16, 2021
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bitcoind broken on latest master

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