From 836b2fe544a5e9b5ce116622cb36fba33838c6fd Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 01:33:23 -0700 Subject: selftests/bpf: Check that JMP32 pointer vs zero jumps are not predicted Add jmp32_ptr_vs_zero_jne: the fall-through of the 32-bit compare, which the verifier used to skip, contains an out of bounds map value access, hence w/o the previous patch the program is accepted. See previous patch for detailed description. Reported-by: Nicholas Carlini Suggested-by: Nicholas Carlini Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- samples/trace_printk/Makefile | 7 +++++ samples/trace_printk/trace-printk.c | 58 +++++++++++++++++++++++++++++++++++++ 2 files changed, 65 insertions(+) create mode 100644 samples/trace_printk/Makefile create mode 100644 samples/trace_printk/trace-printk.c (limited to 'samples/trace_printk') diff --git a/samples/trace_printk/Makefile b/samples/trace_printk/Makefile new file mode 100644 index 000000000..c0df36167 --- /dev/null +++ b/samples/trace_printk/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0-only +# builds a module that calls various trace_printk routines +# then to use one (as root): insmod + +# This module can also be used to test the trace_printk code. + +obj-$(CONFIG_SAMPLE_TRACE_PRINTK) += trace-printk.o diff --git a/samples/trace_printk/trace-printk.c b/samples/trace_printk/trace-printk.c new file mode 100644 index 000000000..cfc159580 --- /dev/null +++ b/samples/trace_printk/trace-printk.c @@ -0,0 +1,58 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include + +/* Must not be static to force gcc to consider these non constant */ +char *trace_printk_test_global_str = + "This is a dynamic string that will use trace_puts\n"; + +char *trace_printk_test_global_str_irq = + "(irq) This is a dynamic string that will use trace_puts\n"; + +char *trace_printk_test_global_str_fmt = + "%sThis is a %s that will use trace_printk\n"; + +static struct irq_work irqwork; + +static void trace_printk_irq_work(struct irq_work *work) +{ + trace_printk("(irq) This is a static string that will use trace_bputs\n"); + trace_printk(trace_printk_test_global_str_irq); + + trace_printk("(irq) This is a %s that will use trace_bprintk()\n", + "static string"); + + trace_printk(trace_printk_test_global_str_fmt, + "(irq) ", "dynamic string"); +} + +static int __init trace_printk_init(void) +{ + init_irq_work(&irqwork, trace_printk_irq_work); + + trace_printk("This is a static string that will use trace_bputs\n"); + trace_printk(trace_printk_test_global_str); + + /* Kick off printing in irq context */ + irq_work_queue(&irqwork); + irq_work_sync(&irqwork); + + trace_printk("This is a %s that will use trace_bprintk()\n", + "static string"); + + trace_printk(trace_printk_test_global_str_fmt, "", "dynamic string"); + + return 0; +} + +static void __exit trace_printk_exit(void) +{ +} + +module_init(trace_printk_init); +module_exit(trace_printk_exit); + +MODULE_AUTHOR("Steven Rostedt"); +MODULE_DESCRIPTION("trace-printk"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1