Revision 832a3aad1e2927b1684e7369c9f36a370e0b95da authored by Chris Wilson on 18 March 2015, 18:19:22 UTC, committed by Jani Nikula on 26 March 2015, 09:05:54 UTC
If we retire requests last, we may use a later seqno and so clear the requests lists without clearing the active list, leading to confusion. Hence we should retire requests first for consistency with the early return. The order used to be important as the lifecycle for the object on the active list was determined by request->seqno. However, the requests themselves are now reference counted removing the constraint from the order of retirement. Fixes regression from commit 1b5a433a4dd967b125131da42b89b5cc0d5b1f57 Author: John Harrison <John.C.Harrison@Intel.com> Date: Mon Nov 24 18:49:42 2014 +0000 drm/i915: Convert 'i915_seqno_passed' calls into 'i915_gem_request_completed ' and a WARNING: CPU: 0 PID: 1383 at drivers/gpu/drm/i915/i915_gem_evict.c:279 i915_gem_evict_vm+0x10c/0x140() WARN_ON(!list_empty(&vm->active_list)) Identified by updating WATCH_LISTS: [drm:i915_verify_lists] *ERROR* blitter ring: active list not empty, but no requests WARNING: CPU: 0 PID: 681 at drivers/gpu/drm/i915/i915_gem.c:2751 i915_gem_retire_requests_ring+0x149/0x230() WARN_ON(i915_verify_lists(ring->dev)) Note that this is only a problem in evict_vm where the following happens after a retire_request has cleaned out all requests, but not all active bo: - intel_ring_idle called from i915_gpu_idle notices that no requests are outstanding and immediately returns. - i915_gem_retire_requests_ring called from i915_gem_retire_requests also immediately returns when there's no request, still leaving the bo on the active list. - evict_vm hits the WARN_ON(!list_empty(&vm->active_list)) after evicting all active objects that there's still stuff left that shouldn't be there. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: John Harrison <John.C.Harrison@Intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
1 parent 59a58cb
bpf-helper.c
/*
* Seccomp BPF helper functions
*
* Copyright (c) 2012 The Chromium OS Authors <chromium-os-dev@chromium.org>
* Author: Will Drewry <wad@chromium.org>
*
* The code may be used by anyone for any purpose,
* and can serve as a starting point for developing
* applications using prctl(PR_ATTACH_SECCOMP_FILTER).
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "bpf-helper.h"
int bpf_resolve_jumps(struct bpf_labels *labels,
struct sock_filter *filter, size_t count)
{
struct sock_filter *begin = filter;
__u8 insn = count - 1;
if (count < 1)
return -1;
/*
* Walk it once, backwards, to build the label table and do fixups.
* Since backward jumps are disallowed by BPF, this is easy.
*/
filter += insn;
for (; filter >= begin; --insn, --filter) {
if (filter->code != (BPF_JMP+BPF_JA))
continue;
switch ((filter->jt<<8)|filter->jf) {
case (JUMP_JT<<8)|JUMP_JF:
if (labels->labels[filter->k].location == 0xffffffff) {
fprintf(stderr, "Unresolved label: '%s'\n",
labels->labels[filter->k].label);
return 1;
}
filter->k = labels->labels[filter->k].location -
(insn + 1);
filter->jt = 0;
filter->jf = 0;
continue;
case (LABEL_JT<<8)|LABEL_JF:
if (labels->labels[filter->k].location != 0xffffffff) {
fprintf(stderr, "Duplicate label use: '%s'\n",
labels->labels[filter->k].label);
return 1;
}
labels->labels[filter->k].location = insn;
filter->k = 0; /* fall through */
filter->jt = 0;
filter->jf = 0;
continue;
}
}
return 0;
}
/* Simple lookup table for labels. */
__u32 seccomp_bpf_label(struct bpf_labels *labels, const char *label)
{
struct __bpf_label *begin = labels->labels, *end;
int id;
if (labels->count == BPF_LABELS_MAX) {
fprintf(stderr, "Too many labels\n");
exit(1);
}
if (labels->count == 0) {
begin->label = label;
begin->location = 0xffffffff;
labels->count++;
return 0;
}
end = begin + labels->count;
for (id = 0; begin < end; ++begin, ++id) {
if (!strcmp(label, begin->label))
return id;
}
begin->label = label;
begin->location = 0xffffffff;
labels->count++;
return id;
}
void seccomp_bpf_print(struct sock_filter *filter, size_t count)
{
struct sock_filter *end = filter + count;
for ( ; filter < end; ++filter)
printf("{ code=%u,jt=%u,jf=%u,k=%u },\n",
filter->code, filter->jt, filter->jf, filter->k);
}
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