Message-ID: <CAJvTgAiH01DcqQHgz_78QS8isCKvLzcQaKb5K93quzRHNMtrLQ@mail.gmail.com>
Date: Fri, 18 Oct 2024 09:57:13 +0530
From: Vamsi Krishna Brahmajosyula <vamsikrishna.brahmajosyula@...il.com>
To: david.e.box@...ux.intel.com
Cc: irenic.rajneesh@...il.com, hdegoede@...hat.com, 
	ilpo.jarvinen@...ux.intel.com, skhan@...uxfoundation.org, 
	platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] platform/x86/intel/pmc: Fix pmc_core_iounmap to call
 iounmap for valid addresses

Hi David,

On Fri, Oct 18, 2024 at 7:42 AM David E. Box
<david.e.box@...ux.intel.com> wrote:
>
> Hi Vamsi,
>
> On Thu, 2024-10-17 at 09:40 +0530, Vamsi Krishna Brahmajosyula wrote:
> > 50c6dbdfd introduced a WARN when adrress ranges of iounmap are
> > invalid. On Thinkpad P1 Gen 7 (Meteor Lake-P) this caused the
> > following warning to appear.
> >
> > WARNING: CPU: 7 PID: 713 at arch/x86/mm/ioremap.c:461 iounmap+0x58/0x1f0
> > Modules linked in: rfkill(+) snd_timer(+) fjes(+) snd soundcore
> > intel_pmc_core(+)
> > int3403_thermal(+) int340x_thermal_zone intel_vsec pmt_telemetry acpi_pad
> > pmt_class
> > acpi_tad int3400_thermal acpi_thermal_rel joydev loop nfnetlink zram xe
> > drm_suballoc_helper
> > nouveau i915 mxm_wmi drm_ttm_helper gpu_sched drm_gpuvm drm_exec drm_buddy
> > i2c_algo_bit
> > crct10dif_pclmul crc32_pclmul ttm crc32c_intel polyval_clmulni rtsx_pci_sdmmc
> > ucsi_acpi
> > polyval_generic mmc_core hid_multitouch drm_display_helper ghash_clmulni_intel
> > typec_ucsi
> > nvme sha512_ssse3 video sha256_ssse3 nvme_core intel_vpu sha1_ssse3 rtsx_pci
> > cec typec
> > nvme_auth i2c_hid_acpi i2c_hid wmi pinctrl_meteorlake serio_raw ip6_tables
> > ip_tables fuse
> > CPU: 7 UID: 0 PID: 713 Comm: (udev-worker) Not tainted 6.12.0-rc2iounmap+ #42
> > Hardware name: LENOVO 21KWCTO1WW/21KWCTO1WW, BIOS N48ET19W (1.06 ) 07/18/2024
> > RIP: 0010:iounmap+0x58/0x1f0
> > Code: 85 6a 01 00 00 48 8b 05 e6 e2 28 04 48 39 c5 72 19 eb 26 cc cc cc 48 ba
> > 00 00 00 00 00 00 32 00 48 8d 44 02 ff 48 39 c5 72 23 <0f> 0b 48 83 c4 08 5b
> > 5d 41 5c c3 cc cc cc cc 48 ba 00 00 00 00 00
> > RSP: 0018:ffff888131eff038 EFLAGS: 00010207
> > RAX: ffffc90000000000 RBX: 0000000000000000 RCX: ffff888e33b80000
> > RDX: dffffc0000000000 RSI: ffff888e33bc29c0 RDI: 0000000000000000
> > RBP: 0000000000000000 R08: ffff8881598a8000 R09: ffff888e2ccedc10
> > R10: 0000000000000003 R11: ffffffffb3367634 R12: 00000000fe000000
> > R13: ffff888101d0da28 R14: ffffffffc2e437e0 R15: ffff888110b03b28
> > FS:  00007f3c1d4b3980(0000) GS:ffff888e33b80000(0000) knlGS:0000000000000000
> > CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: 00005651cfc93578 CR3: 0000000124e4c002 CR4: 0000000000f70ef0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7: 0000000000000400
> > PKRU: 55555554
> > Call Trace:
> > <TASK>
> > ? __warn.cold+0xb6/0x176
> > ? iounmap+0x58/0x1f0
> > ? report_bug+0x1f4/0x2b0
> > ? handle_bug+0x58/0x90
> > ? exc_invalid_op+0x17/0x40
> > ? asm_exc_invalid_op+0x1a/0x20
> > ? iounmap+0x58/0x1f0
> > pmc_core_ssram_get_pmc+0x477/0x6c0 [intel_pmc_core]
> > ? __pfx_pmc_core_ssram_get_pmc+0x10/0x10 [intel_pmc_core]
> > ? __pfx_do_pci_enable_device+0x10/0x10
> > ? pci_wait_for_pending+0x60/0x110
> > ? pci_enable_device_flags+0x1e3/0x2e0
> > ? __pfx_mtl_core_init+0x10/0x10 [intel_pmc_core]
> > pmc_core_ssram_init+0x7f/0x110 [intel_pmc_core]
> > mtl_core_init+0xda/0x130 [intel_pmc_core]
> > ? __mutex_init+0xb9/0x130
> > pmc_core_probe+0x27e/0x10b0 [intel_pmc_core]
> > ? _raw_spin_lock_irqsave+0x96/0xf0
> > ? __pfx_pmc_core_probe+0x10/0x10 [intel_pmc_core]
> > ? __pfx_mutex_unlock+0x10/0x10
> > ? __pfx_mutex_lock+0x10/0x10
> > ? device_pm_check_callbacks+0x82/0x370
> > ? acpi_dev_pm_attach+0x234/0x2b0
> > platform_probe+0x9f/0x150
> > really_probe+0x1e0/0x8a0
> > __driver_probe_device+0x18c/0x370
> > ? __pfx___driver_attach+0x10/0x10
> > driver_probe_device+0x4a/0x120
> > __driver_attach+0x190/0x4a0
> > ? __pfx___driver_attach+0x10/0x10
> > bus_for_each_dev+0x103/0x180
> > ? __pfx_bus_for_each_dev+0x10/0x10
> > ? klist_add_tail+0x136/0x270
> > bus_add_driver+0x2fc/0x540
> > driver_register+0x1a5/0x360
> > ? __pfx_pmc_core_driver_init+0x10/0x10 [intel_pmc_core]
> > do_one_initcall+0xa4/0x380
> > ? __pfx_do_one_initcall+0x10/0x10
> > ? kasan_unpoison+0x44/0x70
> > do_init_module+0x296/0x800
> > load_module+0x5090/0x6ce0
> > ? __pfx_load_module+0x10/0x10
> > ? ima_post_read_file+0x193/0x200
> > ? __pfx_ima_post_read_file+0x10/0x10
> > ? rw_verify_area+0x152/0x4c0
> > ? kernel_read_file+0x257/0x750
> > ? __pfx_kernel_read_file+0x10/0x10
> > ? __pfx_filemap_get_read_batch+0x10/0x10
> > ? init_module_from_file+0xd1/0x130
> > init_module_from_file+0xd1/0x130
> > ? __pfx_init_module_from_file+0x10/0x10
> > ? __pfx__raw_spin_lock+0x10/0x10
> > ? __pfx_cred_has_capability.isra.0+0x10/0x10
> > idempotent_init_module+0x236/0x770
> > ? __pfx_idempotent_init_module+0x10/0x10
> > ? fdget+0x58/0x3f0
> > ? security_capable+0x7d/0x110
> > __x64_sys_finit_module+0xbe/0x130
> > do_syscall_64+0x82/0x160
> > ? __pfx_filemap_read+0x10/0x10
> > ? __pfx___fsnotify_parent+0x10/0x10
> > ? vfs_read+0x3a6/0xa30
> > ? vfs_read+0x3a6/0xa30
> > ? __seccomp_filter+0x175/0xc60
> > ? __pfx___seccomp_filter+0x10/0x10
> > ? fdget_pos+0x1ce/0x500
> > ? syscall_exit_to_user_mode_prepare+0x149/0x170
> > ? syscall_exit_to_user_mode+0x10/0x210
> > ? do_syscall_64+0x8e/0x160
> > ? switch_fpu_return+0xe3/0x1f0
> > ? syscall_exit_to_user_mode+0x1d5/0x210
> > ? do_syscall_64+0x8e/0x160
> > ? exc_page_fault+0x76/0xf0
> > entry_SYSCALL_64_after_hwframe+0x76/0x7e
> > RIP: 0033:0x7f3c1d6d155d
> > Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48
> > 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73
> > 01 c3 48 8b 0d 83 58 0f 00 f7 d8 64 89 01 48
> > RSP: 002b:00007ffe6309db38 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
> > RAX: ffffffffffffffda RBX: 0000557c212550a0 RCX: 00007f3c1d6d155d
> > RDX: 0000000000000000 RSI: 00007f3c1cd943bd RDI: 0000000000000025
> > RBP: 00007ffe6309dbf0 R08: 00007f3c1d7c7b20 R09: 00007ffe6309db80
> > R10: 0000557c21255270 R11: 0000000000000246 R12: 00007f3c1cd943bd
> > R13: 0000000000020000 R14: 0000557c21255c80 R15: 0000557c21255240
> > </TASK>
> > ---[ end trace 0000000000000000 ]---
> >
> > pmc_core_iounmap calls iounmap unconditionally causing the above
> > warning to appear during boot.
> >
> > Fix it by checking for a valid address before calling iounmap.
> >
> > Also the function pmc_core_ssram_get_pmc,
> >       ioremap(ssram_base, SSRAM_HDR_SIZE)
> > returns NULL on the same meteor lake machine even though the
> > ssram_base is valid, return -ENOMEM in such cases.
> >
> > Fixes: a01486dc4bb1 ("platform/x86/intel/pmc: Cleanup SSRAM discovery")
> > Signed-off-by: Vamsi Krishna Brahmajosyula
> > <vamsikrishna.brahmajosyula@...il.com>
> > ---
> >  drivers/platform/x86/intel/pmc/core_ssram.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/platform/x86/intel/pmc/core_ssram.c
> > b/drivers/platform/x86/intel/pmc/core_ssram.c
> > index c259c96b7dfd..8504154b649f 100644
> > --- a/drivers/platform/x86/intel/pmc/core_ssram.c
> > +++ b/drivers/platform/x86/intel/pmc/core_ssram.c
> > @@ -29,7 +29,7 @@
> >  #define LPM_REG_COUNT                28
> >  #define LPM_MODE_OFFSET              1
> >
> > -DEFINE_FREE(pmc_core_iounmap, void __iomem *, iounmap(_T));
> > +DEFINE_FREE(pmc_core_iounmap, void __iomem *, if (_T) iounmap(_T))
> >
> >  static u32 pmc_core_find_guid(struct pmc_info *list, const struct pmc_reg_map
> > *map)
> >  {
> > @@ -262,6 +262,8 @@ pmc_core_ssram_get_pmc(struct pmc_dev *pmcdev, int
> > pmc_idx, u32 offset)
> >
> >       ssram_base = ssram_pcidev->resource[0].start;
> >       tmp_ssram = ioremap(ssram_base, SSRAM_HDR_SIZE);
> > +     if (!tmp_ssram)
> > +             return -ENOMEM;
>
> While this is good to check, I don't think this is where the NULL came from. It
> should be coming from the line,
>
>         ssram = no_free_ptr(tmp_ssram);
>
> This is from the if/else block that chooses an ssram value. In the above line,
> we save the temporary value and do the no_free_ptr() so that we don't end up
> calling iounmap() twice on the same address. However, this does set tmp_ssram to
> NULL so we do need to check for that in the iounmap() handler. Thanks.
Thanks for the review. Since I printed the values after no_free_ptr and assumed
that ioremap assigned it to NULL I had added a return there. I verified it now.

The original commit message is misleading, I shall send a v2 with the
correct explanation.
>
> Reviewed-by: David E. Box <david.e.box@...ux.intel.com>
>
> >
> >       if (pmc_idx != PMC_IDX_MAIN) {
> >               /*
> >
> > base-commit: 2f87d0916ce0d2925cedbc9e8f5d6291ba2ac7b2
>
Thanks,
Vamsi

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