diff options
| author |   Will Deacon <will@kernel.org> | 2020-04-06 20:11:39 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2020-04-07 10:43:44 -0700 |
| commit | d8a84d33a4954b85c53faf77be48b5c2b559692e (patch) | |
| tree | 98282468de89bb90ddeb3a14e3059961df24b7fd /samples/hw_breakpoint/data_breakpoint.c | |
| parent | samples/hw_breakpoint: drop HW_BREAKPOINT_R when reporting writes (diff) | |
| download | wireguard-linux-d8a84d33a4954b85c53faf77be48b5c2b559692e.tar.xz wireguard-linux-d8a84d33a4954b85c53faf77be48b5c2b559692e.zip | |
samples/hw_breakpoint: drop use of kallsyms_lookup_name()
The 'data_breakpoint' test code is the only modular user of
kallsyms_lookup_name(), which was exported as part of fixing the test in
f60d24d2ad04 ("hw-breakpoints: Fix broken hw-breakpoint sample module").
In preparation for un-exporting this symbol, switch the test over to using
__symbol_get(), which can be used to place breakpoints on exported
symbols.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Quentin Perret <qperret@google.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Link: http://lkml.kernel.org/r/20200221114404.14641-3-will@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
| -rw-r--r-- | samples/hw_breakpoint/data_breakpoint.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/samples/hw_breakpoint/data_breakpoint.c b/samples/hw_breakpoint/data_breakpoint.c index 469b36f93696..418c46fe5ffc 100644 --- a/samples/hw_breakpoint/data_breakpoint.c +++ b/samples/hw_breakpoint/data_breakpoint.c @@ -23,7 +23,7 @@ struct perf_event * __percpu *sample_hbp; -static char ksym_name[KSYM_NAME_LEN] = "pid_max"; +static char ksym_name[KSYM_NAME_LEN] = "jiffies"; module_param_string(ksym, ksym_name, KSYM_NAME_LEN, S_IRUGO); MODULE_PARM_DESC(ksym, "Kernel symbol to monitor; this module will report any" " write operations on the kernel symbol"); @@ -41,9 +41,13 @@ static int __init hw_break_module_init(void) { int ret; struct perf_event_attr attr; + void *addr = __symbol_get(ksym_name); + + if (!addr) + return -ENXIO; hw_breakpoint_init(&attr); - attr.bp_addr = kallsyms_lookup_name(ksym_name); + attr.bp_addr = (unsigned long)addr; attr.bp_len = HW_BREAKPOINT_LEN_4; attr.bp_type = HW_BREAKPOINT_W; @@ -66,6 +70,7 @@ fail: static void __exit hw_break_module_exit(void) { unregister_wide_hw_breakpoint(sample_hbp); + symbol_put(ksym_name); printk(KERN_INFO "HW Breakpoint for %s write uninstalled\n", ksym_name); } |