kernel/linux.git/drivers/gpu/drm/i915, branch v5.4.198

drm/i915: Fix -Wstringop-overflow warning in call to intel_read_wm_latency()

2022-06-06T06:33:50+00:00

commit 336feb502a715909a8136eb6a62a83d7268a353b upstream. Fix the following -Wstringop-overflow warnings when building with GCC-11: drivers/gpu/drm/i915/intel_pm.c:3106:9: warning: ‘intel_read_wm_latency’ accessing 16 bytes in a region of size 10 [-Wstringop-overflow=] 3106 | intel_read_wm_latency(dev_priv, dev_priv->wm.pri_latency); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/i915/intel_pm.c:3106:9: note: referencing argument 2 of type ‘u16 *’ {aka ‘short unsigned int *’} drivers/gpu/drm/i915/intel_pm.c:2861:13: note: in a call to function ‘intel_read_wm_latency’ 2861 | static void intel_read_wm_latency(struct drm_i915_private *dev_priv, | ^~~~~~~~~~~~~~~~~~~~~ by removing the over-specified array size from the argument declarations. It seems that this code is actually safe because the size of the array depends on the hardware generation, and the function checks for that. Notice that wm can be an array of 5 elements: drivers/gpu/drm/i915/intel_pm.c:3109: intel_read_wm_latency(dev_priv, dev_priv->wm.pri_latency); or an array of 8 elements: drivers/gpu/drm/i915/intel_pm.c:3131: intel_read_wm_latency(dev_priv, dev_priv->wm.skl_latency); and the compiler legitimately complains about that. This helps with the ongoing efforts to globally enable -Wstringop-overflow. Link: https://github.com/KSPP/linux/issues/181 Signed-off-by: Gustavo A. R. Silva Signed-off-by: Greg Kroah-Hartman

drm/i915: Cast remain to unsigned long in eb_relocate_vma

2022-05-15T17:54:46+00:00

commit 7bf03e7504e433da274963c447648876902b86df upstream. A recent commit in clang added -Wtautological-compare to -Wall, which is enabled for i915 after -Wtautological-compare is disabled for the rest of the kernel so we see the following warning on x86_64: ../drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c:1433:22: warning: result of comparison of constant 576460752303423487 with expression of type 'unsigned int' is always false [-Wtautological-constant-out-of-range-compare] if (unlikely(remain > N_RELOC(ULONG_MAX))) ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~ ../include/linux/compiler.h:78:42: note: expanded from macro 'unlikely' # define unlikely(x) __builtin_expect(!!(x), 0) ^ 1 warning generated. It is not wrong in the case where ULONG_MAX > UINT_MAX but it does not account for the case where this file is built for 32-bit x86, where ULONG_MAX == UINT_MAX and this check is still relevant. Cast remain to unsigned long, which keeps the generated code the same (verified with clang-11 on x86_64 and GCC 9.2.0 on x86 and x86_64) and the warning is silenced so we can catch more potential issues in the future. Closes: https://github.com/ClangBuiltLinux/linux/issues/778 Suggested-by: Michel Dänzer Reviewed-by: Jani Nikula Signed-off-by: Nathan Chancellor Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20200214054706.33870-1-natechancellor@gmail.com Signed-off-by: Greg Kroah-Hartman

drm/i915/overlay: Prevent divide by zero bugs in scaling

2022-02-08T17:24:32+00:00

commit 90a3d22ff02b196d5884e111f39271a1d4ee8e3e upstream. Smatch detected a divide by zero bug in check_overlay_scaling(). drivers/gpu/drm/i915/display/intel_overlay.c:976 check_overlay_scaling() error: potential divide by zero bug '/ rec->dst_height'. drivers/gpu/drm/i915/display/intel_overlay.c:980 check_overlay_scaling() error: potential divide by zero bug '/ rec->dst_width'. Prevent this by ensuring that the dst height and width are non-zero. Fixes: 02e792fbaadb ("drm/i915: implement drmmode overlay support v4") Signed-off-by: Dan Carpenter Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20220124122409.GA31673@kili (cherry picked from commit cf5b64f7f10b28bebb9b7c9d25e7aee5cbe43918) Signed-off-by: Tvrtko Ursulin Signed-off-by: Greg Kroah-Hartman

drm/i915: Flush TLBs before releasing backing store

2022-01-29T09:25:09+00:00

commit 7938d61591d33394a21bdd7797a245b65428f44c upstream. We need to flush TLBs before releasing backing store otherwise userspace is able to encounter stale entries if a) it is not declaring access to certain buffers and b) it races with the backing store release from a such undeclared execution already executing on the GPU in parallel. The approach taken is to mark any buffer objects which were ever bound to the GPU and to trigger a serialized TLB flush when their backing store is released. Alternatively the flushing could be done on VMA unbind, at which point we would be able to ascertain whether there is potential a parallel GPU execution (which could race), but essentially it boils down to paying the cost of TLB flushes potentially needlessly at VMA unbind time (when the backing store is not known to be going away so not needed for safety), versus potentially needlessly at backing store relase time (since we at that point cannot tell whether there is anything executing on the GPU which uses that object). Thereforce simplicity of implementation has been chosen for now with scope to benchmark and refine later as required. Signed-off-by: Tvrtko Ursulin Reported-by: Sushma Venkatesh Reddy Reviewed-by: Daniel Vetter Acked-by: Dave Airlie Cc: Daniel Vetter Cc: Jon Bloomfield Cc: Joonas Lahtinen Cc: Jani Nikula Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

drm/i915: Avoid bitwise vs logical OR warning in snb_wm_latency_quirk()

2022-01-16T08:15:39+00:00

commit 2e70570656adfe1c5d9a29940faa348d5f132199 upstream. A new warning in clang points out a place in this file where a bitwise OR is being used with boolean types: drivers/gpu/drm/i915/intel_pm.c:3066:12: warning: use of bitwise '|' with boolean operands [-Wbitwise-instead-of-logical] changed = ilk_increase_wm_latency(dev_priv, dev_priv->wm.pri_latency, 12) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This construct is intentional, as it allows every one of the calls to ilk_increase_wm_latency() to occur (instead of short circuiting with logical OR) while still caring about the result of each call. To make this clearer to the compiler, use the '|=' operator to assign the result of each ilk_increase_wm_latency() call to changed, which keeps the meaning of the code the same but makes it obvious that every one of these calls is expected to happen. Link: https://github.com/ClangBuiltLinux/linux/issues/1473 Reported-by: Nick Desaulniers Signed-off-by: Nathan Chancellor Suggested-by: Dávid Bolvanský Reviewed-by: Nick Desaulniers Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20211014211916.3550122-1-nathan@kernel.org Signed-off-by: Greg Kroah-Hartman

drm/i915/dp: Ensure sink rate values are always valid

2021-11-26T09:47:22+00:00

commit 6c34bd4532a3f39952952ddc102737595729afc4 upstream. Atm, there are no sink rate values set for DP (vs. eDP) sinks until the DPCD capabilities are successfully read from the sink. During this time intel_dp->num_common_rates is 0 which can lead to a intel_dp->common_rates[-1] (*) access, which is an undefined behaviour, in the following cases: - In intel_dp_sync_state(), if the encoder is enabled without a sink connected to the encoder's connector (BIOS enabled a monitor, but the user unplugged the monitor until the driver loaded). - In intel_dp_sync_state() if the encoder is enabled with a sink connected, but for some reason the DPCD read has failed. - In intel_dp_compute_link_config() if modesetting a connector without a sink connected on it. - In intel_dp_compute_link_config() if modesetting a connector with a a sink connected on it, but before probing the connector first. To avoid the (*) access in all the above cases, make sure that the sink rate table - and hence the common rate table - is always valid, by setting a default minimum sink rate when registering the connector before anything could use it. I also considered setting all the DP link rates by default, so that modesetting with higher resolution modes also succeeds in the last two cases above. However in case a sink is not connected that would stop working after the first modeset, due to the LT fallback logic. So this would need more work, beyond the scope of this fix. As I mentioned in the previous patch, I don't think the issue this patch fixes is user visible, however it is an undefined behaviour by definition and triggers a BUG() in CONFIG_UBSAN builds, hence CC:stable. v2: Clear the default sink rates, before initializing these for eDP. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/4297 References: https://gitlab.freedesktop.org/drm/intel/-/issues/4298 Suggested-by: Ville Syrjälä Cc: Ville Syrjälä Cc: Signed-off-by: Imre Deak Reviewed-by: Ville Syrjälä Acked-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20211018143417.1452632-1-imre.deak@intel.com (cherry picked from commit 3f61ef9777c0ab0f03f4af0ed6fd3e5250537a8d) Signed-off-by: Rodrigo Vivi Signed-off-by: Greg Kroah-Hartman

drm/i915: Fix syncmap memory leak

2021-09-03T08:08:14+00:00

[ Upstream commit a63bcf08f0efb5348105bb8e0e1e8c6671077753 ] A small race exists between intel_gt_retire_requests_timeout and intel_timeline_exit which could result in the syncmap not getting free'd. Rather than work to hard to seal this race, simply cleanup the syncmap on fini. unreferenced object 0xffff88813bc53b18 (size 96): comm "gem_close_race", pid 5410, jiffies 4294917818 (age 1105.600s) hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 00 00 00 00 0a 00 00 00 ................ 00 00 00 00 00 00 00 00 6b 6b 6b 6b 06 00 00 00 ........kkkk.... backtrace: [<00000000120b863a>] __sync_alloc_leaf+0x1e/0x40 [i915] [<00000000042f6959>] __sync_set+0x1bb/0x240 [i915] [<0000000090f0e90f>] i915_request_await_dma_fence+0x1c7/0x400 [i915] [<0000000056a48219>] i915_request_await_object+0x222/0x360 [i915] [<00000000aaac4ee3>] i915_gem_do_execbuffer+0x1bd0/0x2250 [i915] [<000000003c9d830f>] i915_gem_execbuffer2_ioctl+0x405/0xce0 [i915] [<00000000fd7a8e68>] drm_ioctl_kernel+0xb0/0xf0 [drm] [<00000000e721ee87>] drm_ioctl+0x305/0x3c0 [drm] [<000000008b0d8986>] __x64_sys_ioctl+0x71/0xb0 [<0000000076c362a4>] do_syscall_64+0x33/0x80 [<00000000eb7a4831>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Matthew Brost Fixes: 531958f6f357 ("drm/i915/gt: Track timeline activeness in enter/exit") Cc: Reviewed-by: John Harrison Signed-off-by: John Harrison Link: https://patchwork.freedesktop.org/patch/msgid/20210730195342.110234-1-matthew.brost@intel.com (cherry picked from commit faf890985e30d5e88cc3a7c50c1bcad32f89ab7c) Signed-off-by: Rodrigo Vivi Signed-off-by: Sasha Levin

i915: fix build warning in intel_dp_get_link_status()

2021-06-03T06:59:16+00:00

There is a build warning using gcc-11 showing a mis-match in the .h and .c definitions of intel_dp_get_link_status(): CC [M] drivers/gpu/drm/i915/display/intel_dp.o drivers/gpu/drm/i915/display/intel_dp.c:4139:56: warning: argument 2 of type ‘u8[6]’ {aka ‘unsigned char[6]’} with mismatched bound [-Warray-parameter=] 4139 | intel_dp_get_link_status(struct intel_dp *intel_dp, u8 link_status[DP_LINK_STATUS_SIZE]) | ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from drivers/gpu/drm/i915/display/intel_dp.c:51: drivers/gpu/drm/i915/display/intel_dp.h:105:57: note: previously declared as ‘u8 *’ {aka ‘unsigned char *’} 105 | intel_dp_get_link_status(struct intel_dp *intel_dp, u8 *link_status); | ~~~~^~~~~~~~~~~ This was fixed accidentally commit b30edfd8d0b4 ("drm/i915: Switch to LTTPR non-transparent mode link training") by getting rid of the function entirely, but that is not a viable backport for a stable kernel, so just fix up the function definition to remove the build warning entirely. There is no functional change for this, and it fixes up one of the last 'make allmodconfig' build warnings when using gcc-11 on this kernel tree. Signed-off-by: Greg Kroah-Hartman

drm/i915/display: fix compiler warning about array overrun

2021-06-03T06:59:16+00:00

commit fec4d42724a1bf3dcba52307e55375fdb967b852 upstream. intel_dp_check_mst_status() uses a 14-byte array to read the DPRX Event Status Indicator data, but then passes that buffer at offset 10 off as an argument to drm_dp_channel_eq_ok(). End result: there are only 4 bytes remaining of the buffer, yet drm_dp_channel_eq_ok() wants a 6-byte buffer. gcc-11 correctly warns about this case: drivers/gpu/drm/i915/display/intel_dp.c: In function ‘intel_dp_check_mst_status’: drivers/gpu/drm/i915/display/intel_dp.c:3491:22: warning: ‘drm_dp_channel_eq_ok’ reading 6 bytes from a region of size 4 [-Wstringop-overread] 3491 | !drm_dp_channel_eq_ok(&esi[10], intel_dp->lane_count)) { | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/i915/display/intel_dp.c:3491:22: note: referencing argument 1 of type ‘const u8 *’ {aka ‘const unsigned char *’} In file included from drivers/gpu/drm/i915/display/intel_dp.c:38: include/drm/drm_dp_helper.h:1466:6: note: in a call to function ‘drm_dp_channel_eq_ok’ 1466 | bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE], | ^~~~~~~~~~~~~~~~~~~~ 6:14 elapsed This commit just extends the original array by 2 zero-initialized bytes, avoiding the warning. There may be some underlying bug in here that caused this confusion, but this is at least no worse than the existing situation that could use random data off the stack. Cc: Jani Nikula Cc: Ville Syrjälä Cc: Joonas Lahtinen Cc: Rodrigo Vivi Cc: Daniel Vetter Cc: Dave Airlie Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

drm/i915: Avoid div-by-zero on gen2

2021-05-19T08:08:29+00:00

commit 4819d16d91145966ce03818a95169df1fd56b299 upstream. Gen2 tiles are 2KiB in size so i915_gem_object_get_tile_row_size() can in fact return <4KiB, which leads to div-by-zero here. Avoid that. Not sure i915_gem_object_get_tile_row_size() is entirely sane anyway since it doesn't account for the different tile layouts on i8xx/i915... I'm not able to hit this before commit 6846895fde05 ("drm/i915: Replace PIN_NONFAULT with calls to PIN_NOEVICT") and it looks like I also need to run recent version of Mesa. With those in place xonotic trips on this quite easily on my 85x. Cc: stable@vger.kernel.org Reviewed-by: Chris Wilson Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20210421153401.13847-2-ville.syrjala@linux.intel.com (cherry picked from commit ed52c62d386f764194e0184fdb905d5f24194cae) Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman