From f2baaff2798fad7dd6d8cb03672b8024c85142f8 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Thu, 28 May 2020 09:35:11 -0500 Subject: samples: mei: Replace zero-length array with flexible-array MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://github.com/KSPP/linux/issues/21 Signed-off-by: Gustavo A. R. Silva --- samples/mei/mei-amt-version.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'samples') diff --git a/samples/mei/mei-amt-version.c b/samples/mei/mei-amt-version.c index 32234481ad7d..ad3e56042f96 100644 --- a/samples/mei/mei-amt-version.c +++ b/samples/mei/mei-amt-version.c @@ -267,7 +267,7 @@ struct amt_host_if_msg_header { struct amt_host_if_resp_header { struct amt_host_if_msg_header header; uint32_t status; - unsigned char data[0]; + unsigned char data[]; } __attribute__((packed)); const uuid_le MEI_IAMTHIF = UUID_LE(0x12f80028, 0xb4b7, 0x4b2d, \ -- cgit v1.2.3 From 6903cdae9f9f08d61e49c16cbef11c293e33a615 Mon Sep 17 00:00:00 2001 From: Gaurav Singh Date: Fri, 12 Jun 2020 14:53:27 -0400 Subject: bpf, xdp, samples: Fix null pointer dereference in *_user code Memset on the pointer right after malloc can cause a NULL pointer deference if it failed to allocate memory. A simple fix is to replace malloc()/memset() pair with a simple call to calloc(). Fixes: 0fca931a6f21 ("samples/bpf: program demonstrating access to xdp_rxq_info") Signed-off-by: Gaurav Singh Signed-off-by: Daniel Borkmann Acked-by: Jesper Dangaard Brouer Acked-by: John Fastabend --- samples/bpf/xdp_monitor_user.c | 8 ++------ samples/bpf/xdp_redirect_cpu_user.c | 7 ++----- samples/bpf/xdp_rxq_info_user.c | 13 +++---------- 3 files changed, 7 insertions(+), 21 deletions(-) (limited to 'samples') diff --git a/samples/bpf/xdp_monitor_user.c b/samples/bpf/xdp_monitor_user.c index dd558cbb2309..ef53b93db573 100644 --- a/samples/bpf/xdp_monitor_user.c +++ b/samples/bpf/xdp_monitor_user.c @@ -509,11 +509,8 @@ static void *alloc_rec_per_cpu(int record_size) { unsigned int nr_cpus = bpf_num_possible_cpus(); void *array; - size_t size; - size = record_size * nr_cpus; - array = malloc(size); - memset(array, 0, size); + array = calloc(nr_cpus, record_size); if (!array) { fprintf(stderr, "Mem alloc error (nr_cpus:%u)\n", nr_cpus); exit(EXIT_FAIL_MEM); @@ -528,8 +525,7 @@ static struct stats_record *alloc_stats_record(void) int i; /* Alloc main stats_record structure */ - rec = malloc(sizeof(*rec)); - memset(rec, 0, sizeof(*rec)); + rec = calloc(1, sizeof(*rec)); if (!rec) { fprintf(stderr, "Mem alloc error\n"); exit(EXIT_FAIL_MEM); diff --git a/samples/bpf/xdp_redirect_cpu_user.c b/samples/bpf/xdp_redirect_cpu_user.c index f3468168982e..f4e755e0dd73 100644 --- a/samples/bpf/xdp_redirect_cpu_user.c +++ b/samples/bpf/xdp_redirect_cpu_user.c @@ -207,11 +207,8 @@ static struct datarec *alloc_record_per_cpu(void) { unsigned int nr_cpus = bpf_num_possible_cpus(); struct datarec *array; - size_t size; - size = sizeof(struct datarec) * nr_cpus; - array = malloc(size); - memset(array, 0, size); + array = calloc(nr_cpus, sizeof(struct datarec)); if (!array) { fprintf(stderr, "Mem alloc error (nr_cpus:%u)\n", nr_cpus); exit(EXIT_FAIL_MEM); @@ -226,11 +223,11 @@ static struct stats_record *alloc_stats_record(void) size = sizeof(*rec) + n_cpus * sizeof(struct record); rec = malloc(size); - memset(rec, 0, size); if (!rec) { fprintf(stderr, "Mem alloc error\n"); exit(EXIT_FAIL_MEM); } + memset(rec, 0, size); rec->rx_cnt.cpu = alloc_record_per_cpu(); rec->redir_err.cpu = alloc_record_per_cpu(); rec->kthread.cpu = alloc_record_per_cpu(); diff --git a/samples/bpf/xdp_rxq_info_user.c b/samples/bpf/xdp_rxq_info_user.c index 4fe47502ebed..caa4e7ffcfc7 100644 --- a/samples/bpf/xdp_rxq_info_user.c +++ b/samples/bpf/xdp_rxq_info_user.c @@ -198,11 +198,8 @@ static struct datarec *alloc_record_per_cpu(void) { unsigned int nr_cpus = bpf_num_possible_cpus(); struct datarec *array; - size_t size; - size = sizeof(struct datarec) * nr_cpus; - array = malloc(size); - memset(array, 0, size); + array = calloc(nr_cpus, sizeof(struct datarec)); if (!array) { fprintf(stderr, "Mem alloc error (nr_cpus:%u)\n", nr_cpus); exit(EXIT_FAIL_MEM); @@ -214,11 +211,8 @@ static struct record *alloc_record_per_rxq(void) { unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries; struct record *array; - size_t size; - size = sizeof(struct record) * nr_rxqs; - array = malloc(size); - memset(array, 0, size); + array = calloc(nr_rxqs, sizeof(struct record)); if (!array) { fprintf(stderr, "Mem alloc error (nr_rxqs:%u)\n", nr_rxqs); exit(EXIT_FAIL_MEM); @@ -232,8 +226,7 @@ static struct stats_record *alloc_stats_record(void) struct stats_record *rec; int i; - rec = malloc(sizeof(*rec)); - memset(rec, 0, sizeof(*rec)); + rec = calloc(1, sizeof(struct stats_record)); if (!rec) { fprintf(stderr, "Mem alloc error\n"); exit(EXIT_FAIL_MEM); -- cgit v1.2.3 From e9b7b1c0c103a623be1a65c39f98719803440871 Mon Sep 17 00:00:00 2001 From: Kefeng Wang Date: Wed, 10 Jun 2020 01:12:44 +0000 Subject: sample-trace-array: Fix sleeping function called from invalid context BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/5 1 lock held by swapper/5/0: #0: ffff80001002bd90 (samples/ftrace/sample-trace-array.c:38){+.-.}-{0:0}, at: call_timer_fn+0x8/0x3e0 CPU: 5 PID: 0 Comm: swapper/5 Not tainted 5.7.0+ #8 Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 Call trace: dump_backtrace+0x0/0x1a0 show_stack+0x20/0x30 dump_stack+0xe4/0x150 ___might_sleep+0x160/0x200 __might_sleep+0x58/0x90 __mutex_lock+0x64/0x948 mutex_lock_nested+0x3c/0x58 __ftrace_set_clr_event+0x44/0x88 trace_array_set_clr_event+0x24/0x38 mytimer_handler+0x34/0x40 [sample_trace_array] mutex_lock() will be called in interrupt context, using workqueue to fix it. Link: https://lkml.kernel.org/r/20200610011244.2209486-1-wangkefeng.wang@huawei.com Cc: stable@vger.kernel.org Fixes: 89ed42495ef4 ("tracing: Sample module to demonstrate kernel access to Ftrace instances.") Reviewed-by: Divya Indi Signed-off-by: Kefeng Wang Signed-off-by: Steven Rostedt (VMware) --- samples/ftrace/sample-trace-array.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'samples') diff --git a/samples/ftrace/sample-trace-array.c b/samples/ftrace/sample-trace-array.c index d523450d73eb..9e437f930280 100644 --- a/samples/ftrace/sample-trace-array.c +++ b/samples/ftrace/sample-trace-array.c @@ -6,6 +6,7 @@ #include #include #include +#include /* * Any file that uses trace points, must include the header. @@ -20,6 +21,16 @@ struct trace_array *tr; static void mytimer_handler(struct timer_list *unused); static struct task_struct *simple_tsk; +static void trace_work_fn(struct work_struct *work) +{ + /* + * Disable tracing for event "sample_event". + */ + trace_array_set_clr_event(tr, "sample-subsystem", "sample_event", + false); +} +static DECLARE_WORK(trace_work, trace_work_fn); + /* * mytimer: Timer setup to disable tracing for event "sample_event". This * timer is only for the purposes of the sample module to demonstrate access of @@ -29,11 +40,7 @@ static DEFINE_TIMER(mytimer, mytimer_handler); static void mytimer_handler(struct timer_list *unused) { - /* - * Disable tracing for event "sample_event". - */ - trace_array_set_clr_event(tr, "sample-subsystem", "sample_event", - false); + schedule_work(&trace_work); } static void simple_thread_func(int count) @@ -76,6 +83,7 @@ static int simple_thread(void *arg) simple_thread_func(count++); del_timer(&mytimer); + cancel_work_sync(&trace_work); /* * trace_array_put() decrements the reference counter associated with -- cgit v1.2.3 From 9fbc01cdba66e988122ccdc6094cfd85d9587769 Mon Sep 17 00:00:00 2001 From: Kefeng Wang Date: Tue, 9 Jun 2020 13:52:00 +0000 Subject: sample-trace-array: Remove trace_array 'sample-instance' Remove trace_array 'sample-instance' if kthread_run fails in sample_trace_array_init(). Link: https://lkml.kernel.org/r/20200609135200.2206726-1-wangkefeng.wang@huawei.com Cc: stable@vger.kernel.org Fixes: 89ed42495ef4a ("tracing: Sample module to demonstrate kernel access to Ftrace instances.") Reviewed-by: Divya Indi Signed-off-by: Kefeng Wang Signed-off-by: Steven Rostedt (VMware) --- samples/ftrace/sample-trace-array.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'samples') diff --git a/samples/ftrace/sample-trace-array.c b/samples/ftrace/sample-trace-array.c index 9e437f930280..6aba02a31c96 100644 --- a/samples/ftrace/sample-trace-array.c +++ b/samples/ftrace/sample-trace-array.c @@ -115,8 +115,12 @@ static int __init sample_trace_array_init(void) trace_printk_init_buffers(); simple_tsk = kthread_run(simple_thread, NULL, "sample-instance"); - if (IS_ERR(simple_tsk)) + if (IS_ERR(simple_tsk)) { + trace_array_put(tr); + trace_array_destroy(tr); return -1; + } + return 0; } -- cgit v1.2.3 From 214377e9b7e3185abf5998b8a90450e01bab21a7 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 17 Jun 2020 11:08:38 +0900 Subject: samples: watch_queue: build sample program for target architecture This userspace program includes UAPI headers exported to usr/include/. 'make headers' always works for the target architecture (i.e. the same architecture as the kernel), so the sample program should be built for the target as well. Kbuild now supports 'userprogs' for that. I also guarded the CONFIG option by 'depends on CC_CAN_LINK' because $(CC) may not provide libc. Signed-off-by: Masahiro Yamada --- samples/Kconfig | 2 +- samples/watch_queue/Makefile | 10 ++++------ 2 files changed, 5 insertions(+), 7 deletions(-) (limited to 'samples') diff --git a/samples/Kconfig b/samples/Kconfig index f3ac549a53b0..0ed6e4d71d87 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -211,7 +211,7 @@ config SAMPLE_WATCHDOG config SAMPLE_WATCH_QUEUE bool "Build example /dev/watch_queue notification consumer" - depends on HEADERS_INSTALL + depends on CC_CAN_LINK && HEADERS_INSTALL help Build example userspace program to use the new mount_notify(), sb_notify() syscalls and the KEYCTL_WATCH_KEY keyctl() function. diff --git a/samples/watch_queue/Makefile b/samples/watch_queue/Makefile index 8511fb6c53d2..792b22f593cf 100644 --- a/samples/watch_queue/Makefile +++ b/samples/watch_queue/Makefile @@ -1,7 +1,5 @@ -# List of programs to build -hostprogs := watch_test +# SPDX-License-Identifier: GPL-2.0-only +userprogs := watch_test +always-y := $(userprogs) -# Tell kbuild to always build the programs -always-y := $(hostprogs) - -HOSTCFLAGS_watch_test.o += -I$(objtree)/usr/include +userccflags += -I usr/include -- cgit v1.2.3 From c3eeaae9fd736b7f2afbda8d3cbb1cbae06decf3 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 3 Jul 2020 15:15:21 -0700 Subject: samples/vfs: avoid warning in statx override Something changed recently to uncover this warning: samples/vfs/test-statx.c:24:15: warning: `struct foo' declared inside parameter list will not be visible outside of this definition or declaration 24 | #define statx foo | ^~~ Which is due the use of "struct statx" (here, "struct foo") in a function prototype argument list before it has been defined: int # 56 "/usr/include/x86_64-linux-gnu/bits/statx-generic.h" foo # 56 "/usr/include/x86_64-linux-gnu/bits/statx-generic.h" 3 4 (int __dirfd, const char *__restrict __path, int __flags, unsigned int __mask, struct # 57 "/usr/include/x86_64-linux-gnu/bits/statx-generic.h" foo # 57 "/usr/include/x86_64-linux-gnu/bits/statx-generic.h" 3 4 *__restrict __buf) __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__nonnull__ (2, 5))); Add explicit struct before #include to avoid warning. Fixes: f1b5618e013a ("vfs: Add a sample program for the new mount API") Signed-off-by: Kees Cook Signed-off-by: Andrew Morton Cc: Miklos Szeredi Cc: Al Viro Cc: David Howells Link: http://lkml.kernel.org/r/202006282213.C516EA6@keescook Signed-off-by: Linus Torvalds --- samples/vfs/test-statx.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'samples') diff --git a/samples/vfs/test-statx.c b/samples/vfs/test-statx.c index 76c577ea4fd8..49c7a46cee07 100644 --- a/samples/vfs/test-statx.c +++ b/samples/vfs/test-statx.c @@ -23,6 +23,8 @@ #include #define statx foo #define statx_timestamp foo_timestamp +struct statx; +struct statx_timestamp; #include #undef statx #undef statx_timestamp -- cgit v1.2.3