From b2c0cbd657173f024138d6421774007690ceeffd Mon Sep 17 00:00:00 2001 From: Nicolai Stange Date: Tue, 22 Mar 2016 22:05:27 +0100 Subject: drm/radeon: don't include RADEON_HPD_NONE in HPD IRQ enable bitsets 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: [] dump_stack+0xbc/0x117 [] ? _atomic_dec_and_lock+0x169/0x169 [] ubsan_epilogue+0xd/0x4e [] __ubsan_handle_shift_out_of_bounds+0x1fb/0x254 [] ? atom_execute_table+0x3e/0x50 [radeon] [] ? __ubsan_handle_load_invalid_value+0x158/0x158 [] ? radeon_get_pll_use_mask+0x130/0x130 [radeon] [] ? wake_up_klogd_work_func+0x60/0x60 [] ? vprintk_default+0x3e/0x60 [] evergreen_hpd_init+0x274/0x2d0 [radeon] [] ? evergreen_hpd_init+0x274/0x2d0 [radeon] [] radeon_modeset_init+0x8ce/0x18d0 [radeon] [] radeon_driver_load_kms+0x186/0x350 [radeon] [] drm_dev_register+0xc6/0x100 [drm] [] drm_get_pci_dev+0xe4/0x490 [drm] [] ? kfree+0x220/0x370 [] 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 Signed-off-by: Alex Deucher --- drivers/gpu/drm/radeon/r600.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/radeon/r600.c') diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c index d7896bb553a9..9247e7d207fe 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); } -- cgit v1.2.3