Comment 6 for bug 1822871

On Tue, 9 Apr 2019 at 16:30, dann frazier <email address hidden> wrote:
>
> Yeah, no crash anymore - thanks Ard!
>
> ubuntu@d06-4:~$ echo function | sudo tee /sys/kernel/debug/tracing/current_tracer
> function
> [ 72.778123] ftrace: far branches to multiple entry points unsupported inside a single module
>
> ^ I assume this is expected
>

Uhm, not really.

You don't have any out of tree live patching code in your kernel, right?

> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1822871
>
> Title:
> enabling ftrace on Hi1620 CS causes an Oops
>
> Status in linux package in Ubuntu:
> Confirmed
>
> Bug description:
> [Impact]
> Attempting to enable the function tracer causes an Oops. This impacts the current disco kernel, as well as latest upstream (@5e7a8ca319268a70a6c7c3c1fde5bea38e1e5539).
>
> This is 100% reproducible on D06 CS systems, but not reproducible on
> D06 ES systems (the previous silicon rev).
>
> [Test Case]
> $ echo function | sudo tee /sys/kernel/debug/tracing/current_tracer
>
> [ 3125.651453] kernel BUG at arch/arm64/kernel/insn.c:1325!
> [ 3125.656766] Internal error: Oops - BUG: 0 [#1] SMP
> [ 3125.661551] Modules linked in: nls_iso8859_1 ipmi_ssif joydev input_leds tpm_tis_spi hns_roce_hw_v2 hns_roce ib_uverbs spi_dw_mmio ipmi_si spi_dw ipmi_devintf ipmi_msghandler cppc_cpufreq sch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor xor_neon raid6_pq libcrc32c raid1 raid0 multipath linear ses enclosure marvell aes_ce_blk aes_ce_cipher hibmc_drm hid_generic ttm crct10dif_ce drm_kms_helper ghash_ce sha2_ce syscopyarea sha256_arm64 sysfillrect ixgbe igb sha1_ce hns3 sysimgblt usbhid fb_sys_fops hisi_sas_v3_hw hclge i2c_algo_bit xfrm_algo hisi_sas_main mdio hid drm hnae3 libsas ahci scsi_transport_sas hinic gpio_dwapb aes_neon_bs aes_neon_blk crypto_simd cryptd aes_arm64
> [ 3125.736544] CPU: 124 PID: 3306 Comm: tee Not tainted 5.0.0-rc4+ #12
> [ 3125.742802] Hardware name: Huawei TaiShan 2280 V2/BC82AMDA, BIOS TA BIOS 2280-A CS V2.16.01 03/16/2019
> [ 3125.752099] pstate: 00400009 (nzcv daif +PAN -UAO)
> [ 3125.756893] pc : aarch64_insn_adrp_get_offset+0x34/0x38
> [ 3125.762111] lr : plt_entries_equal.part.3+0x40/0x80
> [ 3125.766979] sp : ffff00002837b9f0
> [ 3125.770286] x29: ffff00002837b9f0 x28: ffffbef4fd20d880
> [ 3125.775591] x27: 0000000000000000 x26: 0000000000000000
> [ 3125.780896] x25: 0000ffffdea2a7e8 x24: ffff3dceb8413000
> [ 3125.786200] x23: 0000000000000002 x22: ffff3dce9d2289a4
> [ 3125.791504] x21: ffff00002837ba8c x20: ffff00002837b000
> [ 3125.796808] x19: ffff3dce9d228000 x18: 0000000000000000
> [ 3125.802112] x17: 0000000000000000 x16: ffff3dceb7742780
> [ 3125.807416] x15: ffff3dceb7ce7c38 x14: 0000000000000001
> [ 3125.812720] x13: ffffbef50bb9e188 x12: 0000000000000000
> [ 3125.818023] x11: ffff7efba3e79608 x10: 0000000000000a70
> [ 3125.823327] x9 : ffff3dceb6deeacc x8 : 0000000000000000
> [ 3125.828631] x7 : 0000000000000005 x6 : ffff3dceb8413f10
> [ 3125.833935] x5 : 00000000002b3000 x4 : ffff3dceb6f4f4b8
> [ 3125.839239] x3 : 0000000000000000 x2 : 0000000090000000
> [ 3125.844543] x1 : 0000000000000000 x0 : 0000000000000000
> [ 3125.849850] Process tee (pid: 3306, stack limit = 0x00000000262bb476)
> [ 3125.856281] Call trace:
> [ 3125.858723] aarch64_insn_adrp_get_offset+0x34/0x38
> [ 3125.863593] plt_entries_equal.part.3+0x40/0x80
> [ 3125.868115] plt_entries_equal+0x5c/0x70
> [ 3125.872031] ftrace_make_call+0xf0/0x150
> [ 3125.875950] __ftrace_replace_code+0xe8/0xf8
> [ 3125.880212] ftrace_replace_code+0x64/0xc0
> [ 3125.884301] ftrace_modify_all_code+0xb0/0x148
> [ 3125.888738] arch_ftrace_update_code+0x10/0x18
> [ 3125.893174] ftrace_run_update_code+0x20/0x70
> [ 3125.897524] ftrace_startup_enable+0x4c/0x58
> [ 3125.901788] ftrace_startup+0xa4/0x140
> [ 3125.905531] register_ftrace_function+0x64/0x80
> [ 3125.910059] function_trace_init+0x50/0x98
> [ 3125.914149] tracing_set_tracer+0xf4/0x1c0
> [ 3125.918238] tracing_set_trace_write+0x10c/0x168
> [ 3125.922852] __vfs_write+0x60/0x1a8
> [ 3125.926333] vfs_write+0xac/0x1b8
> [ 3125.929641] ksys_write+0x6c/0xd8
> [ 3125.932949] __arm64_sys_write+0x24/0x30
> [ 3125.936866] el0_svc_common+0x78/0x120
> [ 3125.940608] el0_svc_handler+0x38/0x78
> [ 3125.944349] el0_svc+0x8/0xc
> [ 3125.947224] Code: 97fffb33 53144c00 a8c17bfd d65f03c0 (d4210000)
> [ 3125.953312] ---[ end trace 0872d3e5933385e2 ]---
>
> [Fix]
> TBD
>
> [Regression Risk]
> TBD
>
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