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 --- tools/lib/api/debug.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 tools/lib/api/debug.c (limited to 'tools/lib/api/debug.c') diff --git a/tools/lib/api/debug.c b/tools/lib/api/debug.c new file mode 100644 index 000000000..7708f0558 --- /dev/null +++ b/tools/lib/api/debug.c @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include "debug.h" +#include "debug-internal.h" + +static int __base_pr(const char *format, ...) +{ + va_list args; + int err; + + va_start(args, format); + err = vfprintf(stderr, format, args); + va_end(args); + return err; +} + +libapi_print_fn_t __pr_warn = __base_pr; +libapi_print_fn_t __pr_info = __base_pr; +libapi_print_fn_t __pr_debug; + +void libapi_set_print(libapi_print_fn_t warn, + libapi_print_fn_t info, + libapi_print_fn_t debug) +{ + __pr_warn = warn; + __pr_info = info; + __pr_debug = debug; +} -- cgit v1.3.1