This series attempts to fix the RCU stalls triggered by the x86 crypto drivers discussed in https://lore.kernel.org/all/MW5PR84MB18426EBBA3303770A8BC0BDFAB759@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ The following x86 drivers are enforcing a 4 KiB limit today, using either the SZ_4K macro or a direct reference to 4096 bytes: blake-2s, chacha, nhpoly1305, poly1305, polyval I've included a patch to make them use the same macro name. These are not currently limited, so I've included patches for them: sha*, crc*, sm3, ghash I originally encountered some RCU stalls with tcrypt in aesni: tcrypt: testing encryption speed of sync skcipher cts(cbc(aes)) using cts(cbc(aes-aesni)) tcrypt: testing encryption speed of sync skcipher cfb(aes) using cfb(aes-aesni) tcrypt: testing decryption speed of sync skcipher cfb(aes) using cfb(aes-aesni) but I don't see any problems in the source code. So, no patch is proposed for that driver yet. With various errors inserted, all the drivers failed self-tests or hung boot, so the changes seem functionally correct. I haven't done comprehensive tests of different data sizes and alignments, so please consider this an RFC. I added some counters (not posted) to the drivers to observe their behavior. During boot, the finup function is actually called much more often than update - 1500 calls for 2 GiB via finup vs. 23 KiB via update. The patch breaks that into half a million 4 KiB chunks. /sys/module/sha512_ssse3/parameters/rob_call_finup:1541 /sys/module/sha512_ssse3/parameters/rob_call_finup_fpu:469325 /sys/module/sha512_ssse3/parameters/rob_call_update:174 /sys/module/sha512_ssse3/parameters/rob_call_update_fpu:32 /sys/module/sha512_ssse3/parameters/rob_len_finup:2123048456 /sys/module/sha512_ssse3/parameters/rob_len_update:24120 Robert Elliott (7): rcu: correct CONFIG_EXT_RCU_CPU_STALL_TIMEOUT descriptions crypto: x86/sha - limit FPU preemption crypto: x86/crc - limit FPU preemption crypto: x86/sm3 - limit FPU preemption crypto: x86/ghash - restructure FPU context saving crypto: x86/ghash - limit FPU preemption crypto: x86 - use common macro for FPU limit Documentation/RCU/stallwarn.rst | 9 +++--- arch/x86/crypto/blake2s-glue.c | 7 +++-- arch/x86/crypto/chacha_glue.c | 4 ++- arch/x86/crypto/crc32-pclmul_glue.c | 18 ++++++++--- arch/x86/crypto/crc32c-intel_glue.c | 32 ++++++++++++++++---- arch/x86/crypto/crct10dif-pclmul_glue.c | 32 ++++++++++++++++---- arch/x86/crypto/ghash-clmulni-intel_glue.c | 32 +++++++++++++++----- arch/x86/crypto/nhpoly1305-avx2-glue.c | 3 +- arch/x86/crypto/nhpoly1305-sse2-glue.c | 4 ++- arch/x86/crypto/poly1305_glue.c | 25 +++++++++------- arch/x86/crypto/polyval-clmulni_glue.c | 5 ++-- arch/x86/crypto/sha1_ssse3_glue.c | 34 +++++++++++++++++---- arch/x86/crypto/sha256_ssse3_glue.c | 35 ++++++++++++++++++---- arch/x86/crypto/sha512_ssse3_glue.c | 35 ++++++++++++++++++---- arch/x86/crypto/sm3_avx_glue.c | 28 +++++++++++++---- kernel/rcu/Kconfig.debug | 2 +- 16 files changed, 237 insertions(+), 68 deletions(-) -- 2.37.3
