Re: [GIT PULL] tracing: Fixes for v6.17

[Steven Rostedt]

Linus,

Hold off on this pull request.

On Fri, 22 Aug 2025 12:24:37 -0700
Nathan Chancellor <nathan@xxxxxxxxxx> wrote:

     ftrace: Also allocate and copy hash for reading of filter files  
> 
> I just bisected a crash that I see when running LTP's read_all test
> (which I have statically compiled at [1]) on /sys:

Thanks for the report. Hmm, this passed all my internal tests, but I don't
run LTP (too much setup).

> $ dmesg
> [   62.221518] BUG: kernel NULL pointer dereference, address: 0000000000000000
> [   62.222457] #PF: supervisor read access in kernel mode
> [   62.223068] #PF: error_code(0x0000) - not-present page
> [   62.223720] PGD 1076a2067 P4D 10fe33067 PUD 112688067 PMD 0
> [   62.224436] Oops: Oops: 0000 [#1] SMP NOPTI
> [   62.224939] CPU: 4 UID: 0 PID: 1145 Comm: read_all Not tainted 6.17.0-rc2-00006-g48d06e78b7cb #1 PREEMPT(full)  ab6dff6fe4772c3d341055188b1594d9637c1b0d
> [   62.226579] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022
> [   62.227561] RIP: 0010:ftrace_regex_open+0x153/0x280

This is a big hint.

> [   62.228177] Code: 48 89 04 24 e8 4e af ff ff 48 8b 04 24 48 89 c7 48 8b 00 49 39 fe 75 e8 48 c7 c7 80 b6 55 ba e8 93 7e 10 01 48 8b 45 50 eb 0b <8b> 3e e8 d6 bc ff ff 48 89 45 50 48 85 c0 0f 84 fd 00 00 00 41 f6
> [   62.230434] RSP: 0018:ff4bded7c4e5bba0 EFLAGS: 00010246
> [   62.231052] RAX: 0000000000000000 RBX: ffffffffba728660 RCX: 0000000000000000
> [   62.231983] RDX: ff172e52cc1b2180 RSI: 0000000000000000 RDI: ffffffffba728698
> [   62.232852] RBP: ff172e52c44f3500 R08: ff172e52c3db6c00 R09: ff172e52c3db6c00
> [   62.233725] R10: ff4bded7c4e5bb88 R11: 00000000ffffffff R12: 0000000000000000
> [   62.234594] R13: 0000000000000000 R14: 0000000000000000 R15: ff172e52d45d1240
> [   62.235465] FS:  0000000000449778(0000) GS:ff172e5674a92000(0000) knlGS:0000000000000000
> [   62.236433] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   62.237110] CR2: 0000000000000000 CR3: 00000001144fd006 CR4: 0000000000771ef0
> [   62.237968] PKRU: 55555554

> [1]: https://github.com/nathanchance/env/raw/a98b8aa3a7017f6b1d94ee26dd217a968da81dd1/bin/x86_64/read_all

I'll try this out.

> 
> If there is any other information I can provide or patches I can test, I
> am happy to do so.

Can you send me your .config file?

Thanks,

-- Steve