[PATCH v3] drm/radeon: don't include RADEON_HPD_NONE in HPD IRQ enable bitsets
Alex Deucher
alexdeucher at gmail.com
Wed Mar 23 15:55:52 UTC 2016
On Tue, Mar 22, 2016 at 5:05 PM, Nicolai Stange <nicstange at gmail.com> wrote:
> The values of all but the RADEON_HPD_NONE members of the radeon_hpd_id
> enum transform 1:1 into bit positions within the 'enabled' bitset as
> assembled by evergreen_hpd_init():
>
> enabled |= 1 << radeon_connector->hpd.hpd;
>
> However, if ->hpd.hpd happens to equal RADEON_HPD_NONE == 0xff, UBSAN
> reports
>
> UBSAN: Undefined behaviour in drivers/gpu/drm/radeon/evergreen.c:1867:16
> shift exponent 255 is too large for 32-bit type 'int'
> [...]
> Call Trace:
> [<ffffffff818c4d35>] dump_stack+0xbc/0x117
> [<ffffffff818c4c79>] ? _atomic_dec_and_lock+0x169/0x169
> [<ffffffff819411bb>] ubsan_epilogue+0xd/0x4e
> [<ffffffff81941cbc>] __ubsan_handle_shift_out_of_bounds+0x1fb/0x254
> [<ffffffffa0ba7f2e>] ? atom_execute_table+0x3e/0x50 [radeon]
> [<ffffffff81941ac1>] ? __ubsan_handle_load_invalid_value+0x158/0x158
> [<ffffffffa0b87700>] ? radeon_get_pll_use_mask+0x130/0x130 [radeon]
> [<ffffffff81219930>] ? wake_up_klogd_work_func+0x60/0x60
> [<ffffffff8121a35e>] ? vprintk_default+0x3e/0x60
> [<ffffffffa0c603c4>] evergreen_hpd_init+0x274/0x2d0 [radeon]
> [<ffffffffa0c603c4>] ? evergreen_hpd_init+0x274/0x2d0 [radeon]
> [<ffffffffa0bd196e>] radeon_modeset_init+0x8ce/0x18d0 [radeon]
> [<ffffffffa0b71d86>] radeon_driver_load_kms+0x186/0x350 [radeon]
> [<ffffffffa03b6b16>] drm_dev_register+0xc6/0x100 [drm]
> [<ffffffffa03bc8c4>] drm_get_pci_dev+0xe4/0x490 [drm]
> [<ffffffff814b83f0>] ? kfree+0x220/0x370
> [<ffffffffa0b687c2>] radeon_pci_probe+0x112/0x140 [radeon]
> [...]
> =====================================================================
> radeon 0000:01:00.0: No connectors reported connected with modes
>
> At least on x86, there should be no user-visible impact as there
>
> 1 << 0xff == 1 << (0xff & 31) == 1 << 31
>
> holds and 31 > RADEON_MAX_HPD_PINS. Thus, this patch is a cosmetic one.
>
> All of the above applies analogously to evergreen_hpd_fini(),
> r100_hpd_init(), r100_hpd_fini(), r600_hpd_init(), r600_hpd_fini(),
> rs600_hpd_init() and rs600_hpd_fini()
>
> Silence UBSAN by checking ->hpd.hpd for RADEON_HPD_NONE before oring it
> into the 'enabled' bitset in the *_init()- or the 'disabled' bitset in
> the *_fini()-functions respectively.
>
> Signed-off-by: Nicolai Stange <nicstange at gmail.com>
Applied. thanks!
Alex
> ---
> Applicable to linux-next-20160322.
>
> WARNING: Apart from compilation, the changes to r100.c, r600.c and
> rs600.c are untested!
>
> v2 thread can be found here:
> http://lkml.kernel.org/g/1458562256-2882-1-git-send-email-nicstange@gmail.com
>
> Changes to v2:
> - Fix the very same issue not only for evergreen, but for r100, r600
> and rs600 also.
> - Change the commit's subject and description body accordingly.
>
> Changes to v1:
> - Turn commit message's impact part into a non-impact part.
>
>
> drivers/gpu/drm/radeon/evergreen.c | 6 ++++--
> drivers/gpu/drm/radeon/r100.c | 6 ++++--
> drivers/gpu/drm/radeon/r600.c | 6 ++++--
> drivers/gpu/drm/radeon/rs600.c | 6 ++++--
> 4 files changed, 16 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
> index 76c4bdf..6360717 100644
> --- a/drivers/gpu/drm/radeon/evergreen.c
> +++ b/drivers/gpu/drm/radeon/evergreen.c
> @@ -1864,7 +1864,8 @@ void evergreen_hpd_init(struct radeon_device *rdev)
> break;
> }
> radeon_hpd_set_polarity(rdev, radeon_connector->hpd.hpd);
> - enabled |= 1 << radeon_connector->hpd.hpd;
> + if (radeon_connector->hpd.hpd != RADEON_HPD_NONE)
> + enabled |= 1 << radeon_connector->hpd.hpd;
> }
> radeon_irq_kms_enable_hpd(rdev, enabled);
> }
> @@ -1907,7 +1908,8 @@ void evergreen_hpd_fini(struct radeon_device *rdev)
> default:
> break;
> }
> - disabled |= 1 << radeon_connector->hpd.hpd;
> + if (radeon_connector->hpd.hpd != RADEON_HPD_NONE)
> + disabled |= 1 << radeon_connector->hpd.hpd;
> }
> radeon_irq_kms_disable_hpd(rdev, disabled);
> }
> diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
> index 6e478a2..55687f3 100644
> --- a/drivers/gpu/drm/radeon/r100.c
> +++ b/drivers/gpu/drm/radeon/r100.c
> @@ -592,7 +592,8 @@ void r100_hpd_init(struct radeon_device *rdev)
>
> list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
> struct radeon_connector *radeon_connector = to_radeon_connector(connector);
> - enable |= 1 << radeon_connector->hpd.hpd;
> + if (radeon_connector->hpd.hpd != RADEON_HPD_NONE)
> + enable |= 1 << radeon_connector->hpd.hpd;
> radeon_hpd_set_polarity(rdev, radeon_connector->hpd.hpd);
> }
> radeon_irq_kms_enable_hpd(rdev, enable);
> @@ -614,7 +615,8 @@ void r100_hpd_fini(struct radeon_device *rdev)
>
> list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
> struct radeon_connector *radeon_connector = to_radeon_connector(connector);
> - disable |= 1 << radeon_connector->hpd.hpd;
> + if (radeon_connector->hpd.hpd != RADEON_HPD_NONE)
> + disable |= 1 << radeon_connector->hpd.hpd;
> }
> radeon_irq_kms_disable_hpd(rdev, disable);
> }
> diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
> index f86ab69..f4012ae 100644
> --- a/drivers/gpu/drm/radeon/r600.c
> +++ b/drivers/gpu/drm/radeon/r600.c
> @@ -1002,7 +1002,8 @@ void r600_hpd_init(struct radeon_device *rdev)
> break;
> }
> }
> - enable |= 1 << radeon_connector->hpd.hpd;
> + if (radeon_connector->hpd.hpd != RADEON_HPD_NONE)
> + enable |= 1 << radeon_connector->hpd.hpd;
> radeon_hpd_set_polarity(rdev, radeon_connector->hpd.hpd);
> }
> radeon_irq_kms_enable_hpd(rdev, enable);
> @@ -1055,7 +1056,8 @@ void r600_hpd_fini(struct radeon_device *rdev)
> break;
> }
> }
> - disable |= 1 << radeon_connector->hpd.hpd;
> + if (radeon_connector->hpd.hpd != RADEON_HPD_NONE)
> + disable |= 1 << radeon_connector->hpd.hpd;
> }
> radeon_irq_kms_disable_hpd(rdev, disable);
> }
> diff --git a/drivers/gpu/drm/radeon/rs600.c b/drivers/gpu/drm/radeon/rs600.c
> index 6244f4e..4b35213 100644
> --- a/drivers/gpu/drm/radeon/rs600.c
> +++ b/drivers/gpu/drm/radeon/rs600.c
> @@ -413,7 +413,8 @@ void rs600_hpd_init(struct radeon_device *rdev)
> default:
> break;
> }
> - enable |= 1 << radeon_connector->hpd.hpd;
> + if (radeon_connector->hpd.hpd != RADEON_HPD_NONE)
> + enable |= 1 << radeon_connector->hpd.hpd;
> radeon_hpd_set_polarity(rdev, radeon_connector->hpd.hpd);
> }
> radeon_irq_kms_enable_hpd(rdev, enable);
> @@ -439,7 +440,8 @@ void rs600_hpd_fini(struct radeon_device *rdev)
> default:
> break;
> }
> - disable |= 1 << radeon_connector->hpd.hpd;
> + if (radeon_connector->hpd.hpd != RADEON_HPD_NONE)
> + disable |= 1 << radeon_connector->hpd.hpd;
> }
> radeon_irq_kms_disable_hpd(rdev, disable);
> }
> --
> 2.7.4
>
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