July 2025 - Linux-stable-mirror

[PATCH v4 2/3] drm/amdgpu: Reset the clear flag in buddy during resume

by Arunpravin Paneer Selvam

- Added a handler in DRM buddy manager to reset the cleared flag for the blocks in the freelist. - This is necessary because, upon resuming, the VRAM becomes cluttered with BIOS data, yet the VRAM backend manager believes that everything has been cleared. v2: - Add lock before accessing drm_buddy_clear_reset_blocks()(Matthew Auld) - Force merge the two dirty blocks.(Matthew Auld) - Add a new unit test case for this issue.(Matthew Auld) - Having this function being able to flip the state either way would be good. (Matthew Brost) v3(Matthew Auld): - Do merge step first to avoid the use of extra reset flag. Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam(a)amd.com> Suggested-by: Christian König <christian.koenig(a)amd.com> Reviewed-by: Matthew Auld <matthew.auld(a)intel.com> Cc: stable(a)vger.kernel.org Fixes: a68c7eaa7a8f ("drm/amdgpu: Enable clear page functionality") Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3812 --- drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 + drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 1 + drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 17 ++++++++ drivers/gpu/drm/drm_buddy.c | 43 ++++++++++++++++++++ include/drm/drm_buddy.h | 2 + 5 files changed, 65 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index 723ab95d8c48..ac92220f9fc3 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -5327,6 +5327,8 @@ int amdgpu_device_resume(struct drm_device *dev, bool notify_clients) dev->dev->power.disable_depth--; #endif } + + amdgpu_vram_mgr_clear_reset_blocks(adev); adev->in_suspend = false; if (amdgpu_acpi_smart_shift_update(dev, AMDGPU_SS_DEV_D0)) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h index 215c198e4aff..2309df3f68a9 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h @@ -155,6 +155,7 @@ int amdgpu_vram_mgr_reserve_range(struct amdgpu_vram_mgr *mgr, uint64_t start, uint64_t size); int amdgpu_vram_mgr_query_page_status(struct amdgpu_vram_mgr *mgr, uint64_t start); +void amdgpu_vram_mgr_clear_reset_blocks(struct amdgpu_device *adev); bool amdgpu_res_cpu_visible(struct amdgpu_device *adev, struct ttm_resource *res); diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c index abdc52b0895a..07c936e90d8e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c @@ -782,6 +782,23 @@ uint64_t amdgpu_vram_mgr_vis_usage(struct amdgpu_vram_mgr *mgr) return atomic64_read(&mgr->vis_usage); } +/** + * amdgpu_vram_mgr_clear_reset_blocks - reset clear blocks + * + * @adev: amdgpu device pointer + * + * Reset the cleared drm buddy blocks. + */ +void amdgpu_vram_mgr_clear_reset_blocks(struct amdgpu_device *adev) +{ + struct amdgpu_vram_mgr *mgr = &adev->mman.vram_mgr; + struct drm_buddy *mm = &mgr->mm; + + mutex_lock(&mgr->lock); + drm_buddy_reset_clear(mm, false); + mutex_unlock(&mgr->lock); +} + /** * amdgpu_vram_mgr_intersects - test each drm buddy block for intersection * diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c index a1e652b7631d..a94061f373de 100644 --- a/drivers/gpu/drm/drm_buddy.c +++ b/drivers/gpu/drm/drm_buddy.c @@ -405,6 +405,49 @@ drm_get_buddy(struct drm_buddy_block *block) } EXPORT_SYMBOL(drm_get_buddy); +/** + * drm_buddy_reset_clear - reset blocks clear state + * + * @mm: DRM buddy manager + * @is_clear: blocks clear state + * + * Reset the clear state based on @is_clear value for each block + * in the freelist. + */ +void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear) +{ + u64 root_size, size, start; + unsigned int order; + int i; + + size = mm->size; + for (i = 0; i < mm->n_roots; ++i) { + order = ilog2(size) - ilog2(mm->chunk_size); + start = drm_buddy_block_offset(mm->roots[i]); + __force_merge(mm, start, start + size, order); + + root_size = mm->chunk_size << order; + size -= root_size; + } + + for (i = 0; i <= mm->max_order; ++i) { + struct drm_buddy_block *block; + + list_for_each_entry_reverse(block, &mm->free_list[i], link) { + if (is_clear != drm_buddy_block_is_clear(block)) { + if (is_clear) { + mark_cleared(block); + mm->clear_avail += drm_buddy_block_size(mm, block); + } else { + clear_reset(block); + mm->clear_avail -= drm_buddy_block_size(mm, block); + } + } + } + } +} +EXPORT_SYMBOL(drm_buddy_reset_clear); + /** * drm_buddy_free_block - free a block * diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h index 9689a7c5dd36..513837632b7d 100644 --- a/include/drm/drm_buddy.h +++ b/include/drm/drm_buddy.h @@ -160,6 +160,8 @@ int drm_buddy_block_trim(struct drm_buddy *mm, u64 new_size, struct list_head *blocks); +void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear); + void drm_buddy_free_block(struct drm_buddy *mm, struct drm_buddy_block *block); void drm_buddy_free_list(struct drm_buddy *mm, -- 2.43.0

4 months, 1 week

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[PATCH stable 6.12] selftests/bpf: Set test path for token/obj_priv_implicit_token_envvar

by Shung-Hsi Yu

From: Ihor Solodrai <ihor.solodrai(a)pm.me> Commit f01750aecdfb8bfb02842f60af3d805a3ae7267a upstream. token/obj_priv_implicit_token_envvar test may fail in an environment where the process executing tests can not write to the root path. Example: https://github.com/libbpf/libbpf/actions/runs/11844507007/job/33007897936 Change default path used by the test to /tmp/bpf-token-fs, and make it runtime configurable via an environment variable. Signed-off-by: Ihor Solodrai <ihor.solodrai(a)pm.me> Signed-off-by: Andrii Nakryiko <andrii(a)kernel.org> Link: https://lore.kernel.org/bpf/20241115003853.864397-1-ihor.solodrai@pm.me Signed-off-by: Shung-Hsi Yu <shung-hsi.yu(a)suse.com> --- Without this patch test_prog's token/obj_priv_implicit_token_envvar test will fail. --- .../testing/selftests/bpf/prog_tests/token.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/token.c b/tools/testing/selftests/bpf/prog_tests/token.c index fe86e4fdb89c..c3ab9b6fb069 100644 --- a/tools/testing/selftests/bpf/prog_tests/token.c +++ b/tools/testing/selftests/bpf/prog_tests/token.c @@ -828,8 +828,12 @@ static int userns_obj_priv_btf_success(int mnt_fd, struct token_lsm *lsm_skel) return validate_struct_ops_load(mnt_fd, true /* should succeed */); } +static const char *token_bpffs_custom_dir() +{ + return getenv("BPF_SELFTESTS_BPF_TOKEN_DIR") ?: "/tmp/bpf-token-fs"; +} + #define TOKEN_ENVVAR "LIBBPF_BPF_TOKEN_PATH" -#define TOKEN_BPFFS_CUSTOM "/bpf-token-fs" static int userns_obj_priv_implicit_token(int mnt_fd, struct token_lsm *lsm_skel) { @@ -892,6 +896,7 @@ static int userns_obj_priv_implicit_token(int mnt_fd, struct token_lsm *lsm_skel static int userns_obj_priv_implicit_token_envvar(int mnt_fd, struct token_lsm *lsm_skel) { + const char *custom_dir = token_bpffs_custom_dir(); LIBBPF_OPTS(bpf_object_open_opts, opts); struct dummy_st_ops_success *skel; int err; @@ -909,10 +914,10 @@ static int userns_obj_priv_implicit_token_envvar(int mnt_fd, struct token_lsm *l * BPF token implicitly, unless pointed to it through * LIBBPF_BPF_TOKEN_PATH envvar */ - rmdir(TOKEN_BPFFS_CUSTOM); - if (!ASSERT_OK(mkdir(TOKEN_BPFFS_CUSTOM, 0777), "mkdir_bpffs_custom")) + rmdir(custom_dir); + if (!ASSERT_OK(mkdir(custom_dir, 0777), "mkdir_bpffs_custom")) goto err_out; - err = sys_move_mount(mnt_fd, "", AT_FDCWD, TOKEN_BPFFS_CUSTOM, MOVE_MOUNT_F_EMPTY_PATH); + err = sys_move_mount(mnt_fd, "", AT_FDCWD, custom_dir, MOVE_MOUNT_F_EMPTY_PATH); if (!ASSERT_OK(err, "move_mount_bpffs")) goto err_out; @@ -925,7 +930,7 @@ static int userns_obj_priv_implicit_token_envvar(int mnt_fd, struct token_lsm *l goto err_out; } - err = setenv(TOKEN_ENVVAR, TOKEN_BPFFS_CUSTOM, 1 /*overwrite*/); + err = setenv(TOKEN_ENVVAR, custom_dir, 1 /*overwrite*/); if (!ASSERT_OK(err, "setenv_token_path")) goto err_out; @@ -951,11 +956,11 @@ static int userns_obj_priv_implicit_token_envvar(int mnt_fd, struct token_lsm *l if (!ASSERT_ERR(err, "obj_empty_token_path_load")) goto err_out; - rmdir(TOKEN_BPFFS_CUSTOM); + rmdir(custom_dir); unsetenv(TOKEN_ENVVAR); return 0; err_out: - rmdir(TOKEN_BPFFS_CUSTOM); + rmdir(custom_dir); unsetenv(TOKEN_ENVVAR); return -EINVAL; } -- 2.50.1

4 months, 1 week

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[PATCH] tracing/probes: Avoid using params uninitialized in parse_btf_arg()

by Nathan Chancellor

After a recent change in clang to strengthen uninitialized warnings [1], it points out that in one of the error paths in parse_btf_arg(), params is used uninitialized: kernel/trace/trace_probe.c:660:19: warning: variable 'params' is uninitialized when used here [-Wuninitialized] 660 | return PTR_ERR(params); | ^~~~~~ Match many other NO_BTF_ENTRY error cases and return -ENOENT, clearing up the warning. Cc: stable(a)vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/2110 Fixes: d157d7694460 ("tracing/probes: Support BTF field access from $retval") Link: https://github.com/llvm/llvm-project/commit/2464313eef01c5b1edf0eccf57a32cd… [1] Signed-off-by: Nathan Chancellor <nathan(a)kernel.org> --- kernel/trace/trace_probe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 424751cdf31f..40830a3ecd96 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -657,7 +657,7 @@ static int parse_btf_arg(char *varname, ret = query_btf_context(ctx); if (ret < 0 || ctx->nr_params == 0) { trace_probe_log_err(ctx->offset, NO_BTF_ENTRY); - return PTR_ERR(params); + return -ENOENT; } } params = ctx->params; --- base-commit: 6921d1e07cb5eddec830801087b419194fde0803 change-id: 20250715-trace_probe-fix-const-uninit-warning-7dc3accce903 Best regards, -- Nathan Chancellor <nathan(a)kernel.org>

4 months, 1 week

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[PATCH net v2] net: libwx: fix multicast packets received count

by Jiawen Wu

Multicast good packets received by PF rings that pass ethternet MAC address filtering are counted for rtnl_link_stats64.multicast. The counter is not cleared on read. Fix the duplicate counting on updating statistics. Fixes: 46b92e10d631 ("net: libwx: support hardware statistics") Cc: stable(a)vger.kernel.org Signed-off-by: Jiawen Wu <jiawenwu(a)trustnetic.com> --- v1 -> v2: - add code comment --- drivers/net/ethernet/wangxun/libwx/wx_hw.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ethernet/wangxun/libwx/wx_hw.c b/drivers/net/ethernet/wangxun/libwx/wx_hw.c index 0f4be72116b8..7ae3786d90b8 100644 --- a/drivers/net/ethernet/wangxun/libwx/wx_hw.c +++ b/drivers/net/ethernet/wangxun/libwx/wx_hw.c @@ -2778,6 +2778,8 @@ void wx_update_stats(struct wx *wx) hwstats->fdirmiss += rd32(wx, WX_RDB_FDIR_MISS); } + /* qmprc is not cleared on read, manual reset it */ + hwstats->qmprc = 0; for (i = wx->num_vfs * wx->num_rx_queues_per_pool; i < wx->mac.max_rx_queues; i++) hwstats->qmprc += rd32(wx, WX_PX_MPRC(i)); -- 2.48.1

4 months, 1 week

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[PATCH net 0/3] mptcp: fix fallback-related races

by Matthieu Baerts (NGI0)

This series contains 3 fixes somewhat related to various races we have while handling fallback. The root cause of the issues addressed here is that the check for "we can fallback to tcp now" and the related action are not atomic. That also applies to fallback due to MP_FAIL -- where the window race is even wider. Address the issue introducing an additional spinlock to bundle together all the relevant events, as per patch 1 and 2. These fixes can be backported up to v5.19 and v5.15. Note that mptcp_disconnect() unconditionally clears the fallback status (zeroing msk->flags) but don't touch the `allows_infinite_fallback` flag. Such issue is addressed in patch 3, and can be backported up to v5.17. Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org> --- Paolo Abeni (3): mptcp: make fallback action and fallback decision atomic mptcp: plug races between subflow fail and subflow creation mptcp: reset fallback status gracefully at disconnect() time net/mptcp/options.c | 3 ++- net/mptcp/pm.c | 8 +++++++- net/mptcp/protocol.c | 56 ++++++++++++++++++++++++++++++++++++++++++++-------- net/mptcp/protocol.h | 29 ++++++++++++++++++++------- net/mptcp/subflow.c | 30 +++++++++++++++++----------- 5 files changed, 98 insertions(+), 28 deletions(-) --- base-commit: b640daa2822a39ff76e70200cb2b7b892b896dce change-id: 20250714-net-mptcp-fallback-races-a99f171cf5ca Best regards, -- Matthieu Baerts (NGI0) <matttbe(a)kernel.org>

4 months, 1 week

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[PATCH] drm/msm/dpu: Initialize crtc_state to NULL in dpu_plane_virtual_atomic_check()

by Nathan Chancellor

After a recent change in clang to expose uninitialized warnings from const variables and pointers [1], there is a warning around crtc_state in dpu_plane_virtual_atomic_check(): drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c:1145:6: error: variable 'crtc_state' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] 1145 | if (plane_state->crtc) | ^~~~~~~~~~~~~~~~~ drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c:1149:58: note: uninitialized use occurs here 1149 | ret = dpu_plane_atomic_check_nosspp(plane, plane_state, crtc_state); | ^~~~~~~~~~ drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c:1145:2: note: remove the 'if' if its condition is always true 1145 | if (plane_state->crtc) | ^~~~~~~~~~~~~~~~~~~~~~ 1146 | crtc_state = drm_atomic_get_new_crtc_state(state, drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c:1139:35: note: initialize the variable 'crtc_state' to silence this warning 1139 | struct drm_crtc_state *crtc_state; | ^ | = NULL Initialize crtc_state to NULL like other places in the driver do, so that it is consistently initialized. Cc: stable(a)vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/2106 Fixes: 774bcfb73176 ("drm/msm/dpu: add support for virtual planes") Link: https://github.com/llvm/llvm-project/commit/2464313eef01c5b1edf0eccf57a32cd… [1] Signed-off-by: Nathan Chancellor <nathan(a)kernel.org> --- drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c index 421138bc3cb7..30ff21c01a36 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c @@ -1136,7 +1136,7 @@ static int dpu_plane_virtual_atomic_check(struct drm_plane *plane, struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane); struct dpu_plane_state *pstate = to_dpu_plane_state(plane_state); - struct drm_crtc_state *crtc_state; + struct drm_crtc_state *crtc_state = NULL; int ret; if (IS_ERR(plane_state)) --- base-commit: d3deabe4c619875714b9a844b1a3d9752dbae1dd change-id: 20250715-drm-msm-fix-const-uninit-warning-2b93cef9f1c6 Best regards, -- Nathan Chancellor <nathan(a)kernel.org>

4 months, 1 week

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[PATCH] wifi: mt76: mt7996: Initialize hdr before passing to skb_put_data()

by Nathan Chancellor

A new warning in clang [1] points out a couple of places where a hdr variable is not initialized then passed along to skb_put_data(). drivers/net/wireless/mediatek/mt76/mt7996/mcu.c:1894:21: warning: variable 'hdr' is uninitialized when passed as a const pointer argument here [-Wuninitialized-const-pointer] 1894 | skb_put_data(skb, &hdr, sizeof(hdr)); | ^~~ drivers/net/wireless/mediatek/mt76/mt7996/mcu.c:3386:21: warning: variable 'hdr' is uninitialized when passed as a const pointer argument here [-Wuninitialized-const-pointer] 3386 | skb_put_data(skb, &hdr, sizeof(hdr)); | ^~~ Zero initialize these headers as done in other places in the driver when there is nothing stored in the header. Cc: stable(a)vger.kernel.org Fixes: 98686cd21624 ("wifi: mt76: mt7996: add driver for MediaTek Wi-Fi 7 (802.11be) devices") Link: https://github.com/llvm/llvm-project/commit/00dacf8c22f065cb52efb14cd091d44… [1] Closes: https://github.com/ClangBuiltLinux/linux/issues/2104 Signed-off-by: Nathan Chancellor <nathan(a)kernel.org> --- drivers/net/wireless/mediatek/mt76/mt7996/mcu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c index 994526c65bfc..640abb4dce7f 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c +++ b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c @@ -1879,8 +1879,8 @@ mt7996_mcu_get_mmps_mode(enum ieee80211_smps_mode smps) int mt7996_mcu_set_fixed_rate_ctrl(struct mt7996_dev *dev, void *data, u16 version) { + struct uni_header hdr = {}; struct ra_fixed_rate *req; - struct uni_header hdr; struct sk_buff *skb; struct tlv *tlv; int len; @@ -3373,7 +3373,7 @@ int mt7996_mcu_set_hdr_trans(struct mt7996_dev *dev, bool hdr_trans) { struct { u8 __rsv[4]; - } __packed hdr; + } __packed hdr = {}; struct hdr_trans_blacklist *req_blacklist; struct hdr_trans_en *req_en; struct sk_buff *skb; --- base-commit: eb8352ee2d1e70f916fac02094dca2b435076fa4 change-id: 20250715-mt7996-fix-uninit-const-pointer-01e1dd03d444 Best regards, -- Nathan Chancellor <nathan(a)kernel.org>

4 months, 1 week

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[PATCH linux-6.12.y 1/2] selftests/bpf: Add a test for arena range tree algorithm

by Yifei Liu

From: Alexei Starovoitov <ast(a)kernel.org> Add a test that verifies specific behavior of arena range tree algorithm and adjust existing big_alloc1 test due to use of global data in arena. Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Andrii Nakryiko <andrii(a)kernel.org> Acked-by: Kumar Kartikeya Dwivedi <memxor(a)gmail.com> Link: https://lore.kernel.org/bpf/20241108025616.17625-3-alexei.starovoitov@gmail… (cherry picked from commit e58358afa84e8e271a296459d35d1715c7572013) [Yifei: This commit fixes the failure of verifier_arena_large test over 64k page size kernels. This commit also introduce some new tests targeting the new feature, arena range tree algorithm, which is not in linux-6.12.y, I just comment out the test headers so that it would not be run here. If this feature is introduced later, we can just uncomment those two lines.] Signed-off-by: Yifei Liu <yifei.l.liu(a)oracle.com> --- .../bpf/progs/verifier_arena_large.c | 110 +++++++++++++++++- 1 file changed, 108 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/verifier_arena_large.c b/tools/testing/selftests/bpf/progs/verifier_arena_large.c index 6065f862d964..f318675814c6 100644 --- a/tools/testing/selftests/bpf/progs/verifier_arena_large.c +++ b/tools/testing/selftests/bpf/progs/verifier_arena_large.c @@ -29,12 +29,12 @@ int big_alloc1(void *ctx) if (!page1) return 1; *page1 = 1; - page2 = bpf_arena_alloc_pages(&arena, base + ARENA_SIZE - PAGE_SIZE, + page2 = bpf_arena_alloc_pages(&arena, base + ARENA_SIZE - PAGE_SIZE * 2, 1, NUMA_NO_NODE, 0); if (!page2) return 2; *page2 = 2; - no_page = bpf_arena_alloc_pages(&arena, base + ARENA_SIZE, + no_page = bpf_arena_alloc_pages(&arena, base + ARENA_SIZE - PAGE_SIZE, 1, NUMA_NO_NODE, 0); if (no_page) return 3; @@ -66,4 +66,110 @@ int big_alloc1(void *ctx) #endif return 0; } + +#if defined(__BPF_FEATURE_ADDR_SPACE_CAST) +#define PAGE_CNT 100 +__u8 __arena * __arena page[PAGE_CNT]; /* occupies the first page */ +__u8 __arena *base; + +/* + * Check that arena's range_tree algorithm allocates pages sequentially + * on the first pass and then fills in all gaps on the second pass. + */ +__noinline int alloc_pages(int page_cnt, int pages_atonce, bool first_pass, + int max_idx, int step) +{ + __u8 __arena *pg; + int i, pg_idx; + + for (i = 0; i < page_cnt; i++) { + pg = bpf_arena_alloc_pages(&arena, NULL, pages_atonce, + NUMA_NO_NODE, 0); + if (!pg) + return step; + pg_idx = (pg - base) / PAGE_SIZE; + if (first_pass) { + /* Pages must be allocated sequentially */ + if (pg_idx != i) + return step + 100; + } else { + /* Allocator must fill into gaps */ + if (pg_idx >= max_idx || (pg_idx & 1)) + return step + 200; + } + *pg = pg_idx; + page[pg_idx] = pg; + cond_break; + } + return 0; +} + +//SEC("syscall") +//__success __retval(0) +int big_alloc2(void *ctx) +{ + __u8 __arena *pg; + int i, err; + + base = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0); + if (!base) + return 1; + bpf_arena_free_pages(&arena, (void __arena *)base, 1); + + err = alloc_pages(PAGE_CNT, 1, true, PAGE_CNT, 2); + if (err) + return err; + + /* Clear all even pages */ + for (i = 0; i < PAGE_CNT; i += 2) { + pg = page[i]; + if (*pg != i) + return 3; + bpf_arena_free_pages(&arena, (void __arena *)pg, 1); + page[i] = NULL; + cond_break; + } + + /* Allocate into freed gaps */ + err = alloc_pages(PAGE_CNT / 2, 1, false, PAGE_CNT, 4); + if (err) + return err; + + /* Free pairs of pages */ + for (i = 0; i < PAGE_CNT; i += 4) { + pg = page[i]; + if (*pg != i) + return 5; + bpf_arena_free_pages(&arena, (void __arena *)pg, 2); + page[i] = NULL; + page[i + 1] = NULL; + cond_break; + } + + /* Allocate 2 pages at a time into freed gaps */ + err = alloc_pages(PAGE_CNT / 4, 2, false, PAGE_CNT, 6); + if (err) + return err; + + /* Check pages without freeing */ + for (i = 0; i < PAGE_CNT; i += 2) { + pg = page[i]; + if (*pg != i) + return 7; + cond_break; + } + + pg = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0); + + if (!pg) + return 8; + /* + * The first PAGE_CNT pages are occupied. The new page + * must be above. + */ + if ((pg - base) / PAGE_SIZE < PAGE_CNT) + return 9; + return 0; +} +#endif char _license[] SEC("license") = "GPL"; -- 2.46.0

4 months, 1 week

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[PATCH] mm/ksm: Fix -Wsometimes-uninitialized from clang-21 in advisor_mode_show()

by Nathan Chancellor

After a recent change in clang to expose uninitialized warnings from const variables [1], there is a warning from the if statement in advisor_mode_show(). mm/ksm.c:3687:11: error: variable 'output' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] 3687 | else if (ksm_advisor == KSM_ADVISOR_SCAN_TIME) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/ksm.c:3690:33: note: uninitialized use occurs here 3690 | return sysfs_emit(buf, "%s\n", output); | ^~~~~~ Rewrite the if statement to implicitly make KSM_ADVISOR_NONE the else branch so that it is obvious to the compiler that ksm_advisor can only be KSM_ADVISOR_NONE or KSM_ADVISOR_SCAN_TIME due to the assignments in advisor_mode_store(). Cc: stable(a)vger.kernel.org Fixes: 66790e9a735b ("mm/ksm: add sysfs knobs for advisor") Closes: https://github.com/ClangBuiltLinux/linux/issues/2100 Link: https://github.com/llvm/llvm-project/commit/2464313eef01c5b1edf0eccf57a32cd… [1] Signed-off-by: Nathan Chancellor <nathan(a)kernel.org> --- mm/ksm.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/ksm.c b/mm/ksm.c index 2b0210d41c55..160787bb121c 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -3682,10 +3682,10 @@ static ssize_t advisor_mode_show(struct kobject *kobj, { const char *output; - if (ksm_advisor == KSM_ADVISOR_NONE) - output = "[none] scan-time"; - else if (ksm_advisor == KSM_ADVISOR_SCAN_TIME) + if (ksm_advisor == KSM_ADVISOR_SCAN_TIME) output = "none [scan-time]"; + else + output = "[none] scan-time"; return sysfs_emit(buf, "%s\n", output); } --- base-commit: fed48693bdfeca666f7536ba88a05e9a4e5523b6 change-id: 20250715-ksm-fix-clang-21-uninit-warning-bea5a6b886ce Best regards, -- Nathan Chancellor <nathan(a)kernel.org>

4 months, 1 week

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+ mm-ksm-fix-wsometimes-uninitialized-from-clang-21-in-advisor_mode_show.patch added to mm-hotfixes-unstable branch

by Andrew Morton

The patch titled Subject: mm/ksm: fix -Wsometimes-uninitialized from clang-21 in advisor_mode_show() has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-ksm-fix-wsometimes-uninitialized-from-clang-21-in-advisor_mode_show.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Nathan Chancellor <nathan(a)kernel.org> Subject: mm/ksm: fix -Wsometimes-uninitialized from clang-21 in advisor_mode_show() Date: Tue, 15 Jul 2025 12:56:16 -0700 After a recent change in clang to expose uninitialized warnings from const variables [1], there is a false positive warning from the if statement in advisor_mode_show(). mm/ksm.c:3687:11: error: variable 'output' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] 3687 | else if (ksm_advisor == KSM_ADVISOR_SCAN_TIME) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/ksm.c:3690:33: note: uninitialized use occurs here 3690 | return sysfs_emit(buf, "%s\n", output); | ^~~~~~ Rewrite the if statement to implicitly make KSM_ADVISOR_NONE the else branch so that it is obvious to the compiler that ksm_advisor can only be KSM_ADVISOR_NONE or KSM_ADVISOR_SCAN_TIME due to the assignments in advisor_mode_store(). Link: https://lkml.kernel.org/r/20250715-ksm-fix-clang-21-uninit-warning-v1-1-f44… Fixes: 66790e9a735b ("mm/ksm: add sysfs knobs for advisor") Signed-off-by: Nathan Chancellor <nathan(a)kernel.org> Closes: https://github.com/ClangBuiltLinux/linux/issues/2100 Link: https://github.com/llvm/llvm-project/commit/2464313eef01c5b1edf0eccf57a32cd… [1] Cc: Chengming Zhou <chengming.zhou(a)linux.dev> Cc: David Hildenbrand <david(a)redhat.com> Cc: Stefan Roesch <shr(a)devkernel.io> Cc: xu xin <xu.xin16(a)zte.com.cn> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/ksm.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/mm/ksm.c~mm-ksm-fix-wsometimes-uninitialized-from-clang-21-in-advisor_mode_show +++ a/mm/ksm.c @@ -3669,10 +3669,10 @@ static ssize_t advisor_mode_show(struct { const char *output; - if (ksm_advisor == KSM_ADVISOR_NONE) - output = "[none] scan-time"; - else if (ksm_advisor == KSM_ADVISOR_SCAN_TIME) + if (ksm_advisor == KSM_ADVISOR_SCAN_TIME) output = "none [scan-time]"; + else + output = "[none] scan-time"; return sysfs_emit(buf, "%s\n", output); } _ Patches currently in -mm which might be from nathan(a)kernel.org are mm-ksm-fix-wsometimes-uninitialized-from-clang-21-in-advisor_mode_show.patch panic-add-panic_sys_info-sysctl-to-take-human-readable-string-parameter-fix.patch

4 months, 1 week

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