| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Fri, 22 Oct 2021 12:14:45 -0700
From: Jessica Zhang <jesszhan@...eaurora.org>
To: Rob Clark <robdclark@...il.com>, dri-devel@...ts.freedesktop.org
Cc: freedreno@...ts.freedesktop.org, linux-arm-msm@...r.kernel.org,
Rob Clark <robdclark@...omium.org>,
Sean Paul <sean@...rly.run>, David Airlie <airlied@...ux.ie>,
Daniel Vetter <daniel@...ll.ch>,
Thomas Zimmermann <tzimmermann@...e.de>,
Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
Maxime Ripard <maxime@...no.tech>,
Abhinav Kumar <abhinavk@...eaurora.org>,
Stephen Boyd <swboyd@...omium.org>,
Krishna Manikandan <mkrishn@...eaurora.org>,
Kalyan Thota <kalyan_t@...eaurora.org>,
Jessica Zhang <jesszhan@...eaurora.org>,
Mark Yacoub <markyacoub@...gle.com>,
open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/2] drm/msm/dpu: Remove dynamic allocation from atomic
context
On 10/22/2021 10:20 AM, Rob Clark wrote:
> From: Rob Clark <robdclark@...omium.org>
>
> We know the upper bound on # of mixers (ie. two), so lets just allocate
> this on the stack.
>
> Fixes:
>
> BUG: sleeping function called from invalid context at include/linux/sched/mm.h:201
> in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/0
> INFO: lockdep is turned off.
> irq event stamp: 43642
> hardirqs last enabled at (43641): [<ffffffe24dd276bc>] cpuidle_enter_state+0x158/0x25c
> hardirqs last disabled at (43642): [<ffffffe24dfff450>] enter_el1_irq_or_nmi+0x10/0x1c
> softirqs last enabled at (43620): [<ffffffe24d4103fc>] __do_softirq+0x1e4/0x464
> softirqs last disabled at (43615): [<ffffffe24d48bd90>] __irq_exit_rcu+0x104/0x150
> CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 5.15.0-rc3-debug+ #105
> Hardware name: Google Lazor (rev1 - 2) with LTE (DT)
> Call trace:
> dump_backtrace+0x0/0x18c
> show_stack+0x24/0x30
> dump_stack_lvl+0xa0/0xd4
> dump_stack+0x18/0x34
> ___might_sleep+0x1e0/0x1f0
> __might_sleep+0x78/0x8c
> slab_pre_alloc_hook.constprop.0+0x48/0x6c
> __kmalloc+0xc8/0x21c
> dpu_crtc_vblank_callback+0x158/0x1f8
> dpu_encoder_vblank_callback+0x70/0xc4
> dpu_encoder_phys_vid_vblank_irq+0x50/0x12c
> dpu_core_irq+0x1bc/0x1d0
> dpu_irq+0x1c/0x28
> msm_irq+0x34/0x40
> __handle_irq_event_percpu+0x15c/0x308
> handle_irq_event_percpu+0x3c/0x90
> handle_irq_event+0x54/0x98
> handle_level_irq+0xa0/0xd0
> handle_irq_desc+0x2c/0x44
> generic_handle_domain_irq+0x28/0x34
> dpu_mdss_irq+0x90/0xe8
> handle_irq_desc+0x2c/0x44
> handle_domain_irq+0x54/0x80
> gic_handle_irq+0xd4/0x148
> call_on_irq_stack+0x2c/0x54
> do_interrupt_handler+0x4c/0x64
> el1_interrupt+0x30/0xd0
> el1h_64_irq_handler+0x18/0x24
> el1h_64_irq+0x78/0x7c
> arch_local_irq_enable+0xc/0x14
> cpuidle_enter+0x44/0x5c
> do_idle+0x248/0x268
> cpu_startup_entry+0x30/0x48
> rest_init+0x188/0x19c
> arch_call_rest_init+0x1c/0x28
> start_kernel+0x704/0x744
> __primary_switched+0xc0/0xc8
>
> Fixes: 78d9b458cc21 ("drm/msm/dpu: Add CRC support for DPU")
> Signed-off-by: Rob Clark <robdclark@...omium.org>
> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 16 +++++-----------
> 1 file changed, 5 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> index 0ae397044310..80c0ae688734 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> @@ -182,21 +182,19 @@ static int dpu_crtc_get_crc(struct drm_crtc *crtc)
> {
> struct dpu_crtc_state *crtc_state;
> struct dpu_crtc_mixer *m;
> - u32 *crcs;
> + u32 crcs[CRTC_DUAL_MIXERS];
>
> int i = 0;
> int rc = 0;
>
> crtc_state = to_dpu_crtc_state(crtc->state);
> - crcs = kcalloc(crtc_state->num_mixers, sizeof(*crcs), GFP_KERNEL);
>
> - if (!crcs)
> - return -ENOMEM;
> + static_assert(ARRAY_SIZE(crcs) == ARRAY_SIZE(crtc_state->mixers));
>
Getting a C90 compiler warning for static_assert():
In file included from ./include/linux/bits.h:22,
from ./include/linux/bitops.h:6,
from ./include/linux/kernel.h:12,
from ./include/linux/list.h:9,
from ./include/linux/wait.h:7,
from ./include/linux/wait_bit.h:8,
from ./include/linux/fs.h:6,
from ./include/linux/debugfs.h:15,
from drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:10:
drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c: In function
‘dpu_crtc_get_crc’:
./include/linux/build_bug.h:78:41: warning: ISO C90 forbids mixed
declarations and code [-Wdeclaration-after-statement]
78 | #define __static_assert(expr, msg, ...)
_Static_assert(expr, msg)
| ^~~~~~~~~~~~~~
./include/linux/build_bug.h:77:34: note: in expansion of macro
‘__static_assert’
77 | #define static_assert(expr, ...) __static_assert(expr,
##__VA_ARGS__, #expr)
| ^~~~~~~~~~~~~~~
drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:192:2: note: in expansion
of macro ‘static_assert’
192 | static_assert(ARRAY_SIZE(crcs) ==
ARRAY_SIZE(crtc_state->mixers));
| ^~~~~~~~~~~~~
Can be fixed by moving the static_assert() before `crtc_state = ...`
Thanks,
Jessica Zhang
> /* Skip first 2 frames in case of "uncooked" CRCs */
> if (crtc_state->crc_frame_skip_count < 2) {
> crtc_state->crc_frame_skip_count++;
> - goto cleanup;
> + return 0;
> }
>
> for (i = 0; i < crtc_state->num_mixers; ++i) {
> @@ -210,16 +208,12 @@ static int dpu_crtc_get_crc(struct drm_crtc *crtc)
>
> if (rc) {
> DRM_DEBUG_DRIVER("MISR read failed\n");
> - goto cleanup;
> + return rc;
> }
> }
>
> - rc = drm_crtc_add_crc_entry(crtc, true,
> + return drm_crtc_add_crc_entry(crtc, true,
> drm_crtc_accurate_vblank_count(crtc), crcs);
> -
> -cleanup:
> - kfree(crcs);
> - return rc;
> }
>
> static bool dpu_crtc_get_scanout_position(struct drm_crtc *crtc,
Powered by blists - more mailing lists