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authorLinus Torvalds <torvalds@linux-foundation.org>2025-05-28 15:52:42 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2025-05-28 15:52:42 -0700
commit90b83efa6701656e02c86e7df2cb1765ea602d07 (patch)
tree59ac0306b5fe287af6691717ebcdbcc96163c3ca /drivers
parent1b98f357dadd6ea613a435fbaef1a5dd7b35fd21 (diff)
parentc5cebb241e27ed0c3f4c1d2ce63089398e0ed17e (diff)
Merge tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextHEADmaster
Pull bpf updates from Alexei Starovoitov: - Fix and improve BTF deduplication of identical BTF types (Alan Maguire and Andrii Nakryiko) - Support up to 12 arguments in BPF trampoline on arm64 (Xu Kuohai and Alexis Lothoré) - Support load-acquire and store-release instructions in BPF JIT on riscv64 (Andrea Parri) - Fix uninitialized values in BPF_{CORE,PROBE}_READ macros (Anton Protopopov) - Streamline allowed helpers across program types (Feng Yang) - Support atomic update for hashtab of BPF maps (Hou Tao) - Implement json output for BPF helpers (Ihor Solodrai) - Several s390 JIT fixes (Ilya Leoshkevich) - Various sockmap fixes (Jiayuan Chen) - Support mmap of vmlinux BTF data (Lorenz Bauer) - Support BPF rbtree traversal and list peeking (Martin KaFai Lau) - Tests for sockmap/sockhash redirection (Michal Luczaj) - Introduce kfuncs for memory reads into dynptrs (Mykyta Yatsenko) - Add support for dma-buf iterators in BPF (T.J. Mercier) - The verifier support for __bpf_trap() (Yonghong Song) * tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (135 commits) bpf, arm64: Remove unused-but-set function and variable. selftests/bpf: Add tests with stack ptr register in conditional jmp bpf: Do not include stack ptr register in precision backtracking bookkeeping selftests/bpf: enable many-args tests for arm64 bpf, arm64: Support up to 12 function arguments bpf: Check rcu_read_lock_trace_held() in bpf_map_lookup_percpu_elem() bpf: Avoid __bpf_prog_ret0_warn when jit fails bpftool: Add support for custom BTF path in prog load/loadall selftests/bpf: Add unit tests with __bpf_trap() kfunc bpf: Warn with __bpf_trap() kfunc maybe due to uninitialized variable bpf: Remove special_kfunc_set from verifier selftests/bpf: Add test for open coded dmabuf_iter selftests/bpf: Add test for dmabuf_iter bpf: Add open coded dmabuf iterator bpf: Add dmabuf iterator dma-buf: Rename debugfs symbols bpf: Fix error return value in bpf_copy_from_user_dynptr libbpf: Use mmap to parse vmlinux BTF from sysfs selftests: bpf: Add a test for mmapable vmlinux BTF btf: Allow mmap of vmlinux btf ...
Diffstat (limited to 'drivers')
-rw-r--r--drivers/dma-buf/dma-buf.c98
1 files changed, 78 insertions, 20 deletions
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 0c48d41dd5eb..890ecac04dac 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -19,7 +19,9 @@
#include <linux/anon_inodes.h>
#include <linux/export.h>
#include <linux/debugfs.h>
+#include <linux/list.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/seq_file.h>
#include <linux/sync_file.h>
#include <linux/poll.h>
@@ -35,35 +37,91 @@
static inline int is_dma_buf_file(struct file *);
-#if IS_ENABLED(CONFIG_DEBUG_FS)
-static DEFINE_MUTEX(debugfs_list_mutex);
-static LIST_HEAD(debugfs_list);
+static DEFINE_MUTEX(dmabuf_list_mutex);
+static LIST_HEAD(dmabuf_list);
-static void __dma_buf_debugfs_list_add(struct dma_buf *dmabuf)
+static void __dma_buf_list_add(struct dma_buf *dmabuf)
{
- mutex_lock(&debugfs_list_mutex);
- list_add(&dmabuf->list_node, &debugfs_list);
- mutex_unlock(&debugfs_list_mutex);
+ mutex_lock(&dmabuf_list_mutex);
+ list_add(&dmabuf->list_node, &dmabuf_list);
+ mutex_unlock(&dmabuf_list_mutex);
}
-static void __dma_buf_debugfs_list_del(struct dma_buf *dmabuf)
+static void __dma_buf_list_del(struct dma_buf *dmabuf)
{
if (!dmabuf)
return;
- mutex_lock(&debugfs_list_mutex);
+ mutex_lock(&dmabuf_list_mutex);
list_del(&dmabuf->list_node);
- mutex_unlock(&debugfs_list_mutex);
+ mutex_unlock(&dmabuf_list_mutex);
}
-#else
-static void __dma_buf_debugfs_list_add(struct dma_buf *dmabuf)
+
+/**
+ * dma_buf_iter_begin - begin iteration through global list of all DMA buffers
+ *
+ * Returns the first buffer in the global list of DMA-bufs that's not in the
+ * process of being destroyed. Increments that buffer's reference count to
+ * prevent buffer destruction. Callers must release the reference, either by
+ * continuing iteration with dma_buf_iter_next(), or with dma_buf_put().
+ *
+ * Return:
+ * * First buffer from global list, with refcount elevated
+ * * NULL if no active buffers are present
+ */
+struct dma_buf *dma_buf_iter_begin(void)
{
+ struct dma_buf *ret = NULL, *dmabuf;
+
+ /*
+ * The list mutex does not protect a dmabuf's refcount, so it can be
+ * zeroed while we are iterating. We cannot call get_dma_buf() since the
+ * caller may not already own a reference to the buffer.
+ */
+ mutex_lock(&dmabuf_list_mutex);
+ list_for_each_entry(dmabuf, &dmabuf_list, list_node) {
+ if (file_ref_get(&dmabuf->file->f_ref)) {
+ ret = dmabuf;
+ break;
+ }
+ }
+ mutex_unlock(&dmabuf_list_mutex);
+ return ret;
}
-static void __dma_buf_debugfs_list_del(struct dma_buf *dmabuf)
+/**
+ * dma_buf_iter_next - continue iteration through global list of all DMA buffers
+ * @dmabuf: [in] pointer to dma_buf
+ *
+ * Decrements the reference count on the provided buffer. Returns the next
+ * buffer from the remainder of the global list of DMA-bufs with its reference
+ * count incremented. Callers must release the reference, either by continuing
+ * iteration with dma_buf_iter_next(), or with dma_buf_put().
+ *
+ * Return:
+ * * Next buffer from global list, with refcount elevated
+ * * NULL if no additional active buffers are present
+ */
+struct dma_buf *dma_buf_iter_next(struct dma_buf *dmabuf)
{
+ struct dma_buf *ret = NULL;
+
+ /*
+ * The list mutex does not protect a dmabuf's refcount, so it can be
+ * zeroed while we are iterating. We cannot call get_dma_buf() since the
+ * caller may not already own a reference to the buffer.
+ */
+ mutex_lock(&dmabuf_list_mutex);
+ dma_buf_put(dmabuf);
+ list_for_each_entry_continue(dmabuf, &dmabuf_list, list_node) {
+ if (file_ref_get(&dmabuf->file->f_ref)) {
+ ret = dmabuf;
+ break;
+ }
+ }
+ mutex_unlock(&dmabuf_list_mutex);
+ return ret;
}
-#endif
static char *dmabuffs_dname(struct dentry *dentry, char *buffer, int buflen)
{
@@ -115,7 +173,7 @@ static int dma_buf_file_release(struct inode *inode, struct file *file)
if (!is_dma_buf_file(file))
return -EINVAL;
- __dma_buf_debugfs_list_del(file->private_data);
+ __dma_buf_list_del(file->private_data);
return 0;
}
@@ -685,7 +743,7 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
file->f_path.dentry->d_fsdata = dmabuf;
dmabuf->file = file;
- __dma_buf_debugfs_list_add(dmabuf);
+ __dma_buf_list_add(dmabuf);
return dmabuf;
@@ -1563,7 +1621,7 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused)
size_t size = 0;
int ret;
- ret = mutex_lock_interruptible(&debugfs_list_mutex);
+ ret = mutex_lock_interruptible(&dmabuf_list_mutex);
if (ret)
return ret;
@@ -1572,7 +1630,7 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused)
seq_printf(s, "%-8s\t%-8s\t%-8s\t%-8s\texp_name\t%-8s\tname\n",
"size", "flags", "mode", "count", "ino");
- list_for_each_entry(buf_obj, &debugfs_list, list_node) {
+ list_for_each_entry(buf_obj, &dmabuf_list, list_node) {
ret = dma_resv_lock_interruptible(buf_obj->resv, NULL);
if (ret)
@@ -1609,11 +1667,11 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused)
seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size);
- mutex_unlock(&debugfs_list_mutex);
+ mutex_unlock(&dmabuf_list_mutex);
return 0;
error_unlock:
- mutex_unlock(&debugfs_list_mutex);
+ mutex_unlock(&dmabuf_list_mutex);
return ret;
}