From 2b97956af60810cd382b86b9ce9aea421b889861 Mon Sep 17 00:00:00 2001 From: Nuoqi Gui Date: Fri, 4 Sep 2026 12:41:55 +0200 Subject: selftests/bpf: Test rhtab kptr cancellation semantics Resizable hash-map updates and deletions must not perform full special-field destruction in their caller context. In particular, a referenced kptr must remain attached to the allocation until the memory allocator destructor can release it safely. Add separate coverage for both affected paths. The update test stores a task kptr, replaces the ordinary value bytes with BPF_EXIST, and verifies that the kptr survived. The delete test removes an element and exchanges its kptr through the still-valid map-value pointer before the allocation is reclaimed. Both cases observe a NULL kptr when rhtab uses bpf_obj_free_fields(). They recover and release the reference after rhtab switches to cancellation semantics. Signed-off-by: Nuoqi Gui [ kkd: Split update and delete coverage and rewrote the commit log ] Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904104203.345917-5-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- drivers/gpu/trace/Kconfig | 13 +++++++++++++ drivers/gpu/trace/Makefile | 3 +++ drivers/gpu/trace/trace_gpu_mem.c | 13 +++++++++++++ 3 files changed, 29 insertions(+) create mode 100644 drivers/gpu/trace/Kconfig create mode 100644 drivers/gpu/trace/Makefile create mode 100644 drivers/gpu/trace/trace_gpu_mem.c (limited to 'drivers/gpu/trace') diff --git a/drivers/gpu/trace/Kconfig b/drivers/gpu/trace/Kconfig new file mode 100644 index 000000000..cd3d19c4a --- /dev/null +++ b/drivers/gpu/trace/Kconfig @@ -0,0 +1,13 @@ +# SPDX-License-Identifier: GPL-2.0-only + +config TRACE_GPU_MEM + bool "Enable GPU memory usage tracepoints" + default n + help + Choose this option to enable tracepoints for tracking + global and per-process GPU memory usage. Intended for + performance profiling and required for Android. + + Tracepoint availability varies by GPU driver. + + If in doubt, say "N". diff --git a/drivers/gpu/trace/Makefile b/drivers/gpu/trace/Makefile new file mode 100644 index 000000000..b70fbdc58 --- /dev/null +++ b/drivers/gpu/trace/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_TRACE_GPU_MEM) += trace_gpu_mem.o diff --git a/drivers/gpu/trace/trace_gpu_mem.c b/drivers/gpu/trace/trace_gpu_mem.c new file mode 100644 index 000000000..01e855897 --- /dev/null +++ b/drivers/gpu/trace/trace_gpu_mem.c @@ -0,0 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * GPU memory trace points + * + * Copyright (C) 2020 Google, Inc. + */ + +#include + +#define CREATE_TRACE_POINTS +#include + +EXPORT_TRACEPOINT_SYMBOL(gpu_mem_total); -- cgit v1.3.1