* [PATCH v2] kprobes: use DEFINE_DEBUGFS_ATTRIBUTE for the enabled knob @ 2026-08-18 1:53 Bradley Morgan 2026-08-18 23:08 ` Masami Hiramatsu 0 siblings, 1 reply; 6+ messages in thread From: Bradley Morgan @ 2026-08-18 1:53 UTC (permalink / raw) To: Naveen N Rao, David S . Miller, Masami Hiramatsu Cc: linux-kernel, linux-trace-kernel This enabled knob is a disgusting terrible hack. It has rolled its own read/write pair since 2007, writing '1' or '0' into a three byte buffer by hand just to print a single character, with an XXX comment begging debugfs for write callbacks on bool files. DEFINE_DEBUGFS_ATTRIBUTE showed up in 2016 and does exactly that, so the disgusting terrible hack has outlived its excuse for nine years. Kill it, and the stale comment with it. The behavior does not change, except the write only accepts 0/1 now instead of y/n/on/off, and nothing uses anything else. Signed-off-by: Bradley Morgan <include@grrlz.net> --- Changes since v1: - Added the missing Signed-off-by, sorry. kernel/kprobes.c | 43 +++++++++---------------------------------- 1 file changed, 9 insertions(+), 34 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index bfc89083daa9..044c6b5fd2aa 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -3013,47 +3013,22 @@ static int disarm_all_kprobes(void) return ret; } -/* - * XXX: The debugfs bool file interface doesn't allow for callbacks - * when the bool state is switched. We can reuse that facility when - * available - */ -static ssize_t read_enabled_file_bool(struct file *file, - char __user *user_buf, size_t count, loff_t *ppos) +static int kprobes_enabled_set(void *data, u64 val) { - char buf[3]; + if (val) + return arm_all_kprobes(); - if (!kprobes_all_disarmed) - buf[0] = '1'; - else - buf[0] = '0'; - buf[1] = '\n'; - buf[2] = 0x00; - return simple_read_from_buffer(user_buf, count, ppos, buf, 2); + return disarm_all_kprobes(); } -static ssize_t write_enabled_file_bool(struct file *file, - const char __user *user_buf, size_t count, loff_t *ppos) +static int kprobes_enabled_get(void *data, u64 *val) { - bool enable; - int ret; - - ret = kstrtobool_from_user(user_buf, count, &enable); - if (ret) - return ret; - - ret = enable ? arm_all_kprobes() : disarm_all_kprobes(); - if (ret) - return ret; - - return count; + *val = !kprobes_all_disarmed; + return 0; } -static const struct file_operations fops_kp = { - .read = read_enabled_file_bool, - .write = write_enabled_file_bool, - .llseek = default_llseek, -}; +DEFINE_DEBUGFS_ATTRIBUTE(fops_kp, kprobes_enabled_get, + kprobes_enabled_set, "%llu\n"); static int __init debugfs_kprobe_init(void) { -- 2.47.3 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2] kprobes: use DEFINE_DEBUGFS_ATTRIBUTE for the enabled knob 2026-08-18 1:53 [PATCH v2] kprobes: use DEFINE_DEBUGFS_ATTRIBUTE for the enabled knob Bradley Morgan @ 2026-08-18 23:08 ` Masami Hiramatsu 2026-08-18 23:12 ` Bradley Morgan 0 siblings, 1 reply; 6+ messages in thread From: Masami Hiramatsu @ 2026-08-18 23:08 UTC (permalink / raw) To: Bradley Morgan Cc: Naveen N Rao, David S . Miller, linux-kernel, linux-trace-kernel On Tue, 18 Aug 2026 01:53:18 +0000 Bradley Morgan <include@grrlz.net> wrote: > This enabled knob is a disgusting terrible hack. It has rolled its > own read/write pair since 2007, writing '1' or '0' into a three byte > buffer by hand just to print a single character, with an XXX comment > begging debugfs for write callbacks on bool files. > DEFINE_DEBUGFS_ATTRIBUTE showed up in 2016 and does exactly that, so > the disgusting terrible hack has outlived its excuse for nine years. > Kill it, and the stale comment with it. In other words, does this mean something like the following? This "enable" knob implemented custom read/write logic, manually writing "1" or "0" to a 3-byte buffer solely to output a single character. As suggested by comments calling for `debugfs` to support write callbacks for boolean files, using `DEFINE_DEBUGFS_ATTRIBUTE` eliminates the need for these callbacks. Thanks, > > The behavior does not change, except the write only accepts 0/1 now > instead of y/n/on/off, and nothing uses anything else. > > Signed-off-by: Bradley Morgan <include@grrlz.net> > --- > Changes since v1: > - Added the missing Signed-off-by, sorry. > > kernel/kprobes.c | 43 +++++++++---------------------------------- > 1 file changed, 9 insertions(+), 34 deletions(-) > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index bfc89083daa9..044c6b5fd2aa 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -3013,47 +3013,22 @@ static int disarm_all_kprobes(void) > return ret; > } > > -/* > - * XXX: The debugfs bool file interface doesn't allow for callbacks > - * when the bool state is switched. We can reuse that facility when > - * available > - */ > -static ssize_t read_enabled_file_bool(struct file *file, > - char __user *user_buf, size_t count, loff_t *ppos) > +static int kprobes_enabled_set(void *data, u64 val) > { > - char buf[3]; > + if (val) > + return arm_all_kprobes(); > > - if (!kprobes_all_disarmed) > - buf[0] = '1'; > - else > - buf[0] = '0'; > - buf[1] = '\n'; > - buf[2] = 0x00; > - return simple_read_from_buffer(user_buf, count, ppos, buf, 2); > + return disarm_all_kprobes(); > } > > -static ssize_t write_enabled_file_bool(struct file *file, > - const char __user *user_buf, size_t count, loff_t *ppos) > +static int kprobes_enabled_get(void *data, u64 *val) > { > - bool enable; > - int ret; > - > - ret = kstrtobool_from_user(user_buf, count, &enable); > - if (ret) > - return ret; > - > - ret = enable ? arm_all_kprobes() : disarm_all_kprobes(); > - if (ret) > - return ret; > - > - return count; > + *val = !kprobes_all_disarmed; > + return 0; > } > > -static const struct file_operations fops_kp = { > - .read = read_enabled_file_bool, > - .write = write_enabled_file_bool, > - .llseek = default_llseek, > -}; > +DEFINE_DEBUGFS_ATTRIBUTE(fops_kp, kprobes_enabled_get, > + kprobes_enabled_set, "%llu\n"); > > static int __init debugfs_kprobe_init(void) > { > -- > 2.47.3 > -- Masami Hiramatsu (Google) <mhiramat@kernel.org> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] kprobes: use DEFINE_DEBUGFS_ATTRIBUTE for the enabled knob 2026-08-18 23:08 ` Masami Hiramatsu @ 2026-08-18 23:12 ` Bradley Morgan 2026-08-20 15:14 ` Bradley Morgan 0 siblings, 1 reply; 6+ messages in thread From: Bradley Morgan @ 2026-08-18 23:12 UTC (permalink / raw) To: Masami Hiramatsu Cc: Naveen N Rao, David S . Miller, linux-kernel, linux-trace-kernel On 19 August 2026 00:08:13 BST, Masami Hiramatsu <mhiramat@kernel.org> wrote: >On Tue, 18 Aug 2026 01:53:18 +0000 >Bradley Morgan <include@grrlz.net> wrote: > >> This enabled knob is a disgusting terrible hack. It has rolled its >> own read/write pair since 2007, writing '1' or '0' into a three byte >> buffer by hand just to print a single character, with an XXX comment >> begging debugfs for write callbacks on bool files. >> DEFINE_DEBUGFS_ATTRIBUTE showed up in 2016 and does exactly that, so >> the disgusting terrible hack has outlived its excuse for nine years. >> Kill it, and the stale comment with it. > >In other words, does this mean something like the following? > >This "enable" knob implemented custom read/write logic, manually writing >"1" or "0" to a 3-byte buffer solely to output a single character. As >suggested by comments calling for `debugfs` to support write callbacks >for boolean files, using `DEFINE_DEBUGFS_ATTRIBUTE` eliminates the need >for these callbacks. > ehhhhh, well, my description very well tells someone about why this is bad, and a hack, and everything. Your description is good though... But I love to have my personality in my descriptions :( >Thanks, > >> >> The behavior does not change, except the write only accepts 0/1 now >> instead of y/n/on/off, and nothing uses anything else. >> >> Signed-off-by: Bradley Morgan <include@grrlz.net> >> --- >> Changes since v1: >> - Added the missing Signed-off-by, sorry. >> >> kernel/kprobes.c | 43 +++++++++---------------------------------- >> 1 file changed, 9 insertions(+), 34 deletions(-) >> >> diff --git a/kernel/kprobes.c b/kernel/kprobes.c >> index bfc89083daa9..044c6b5fd2aa 100644 >> --- a/kernel/kprobes.c >> +++ b/kernel/kprobes.c >> @@ -3013,47 +3013,22 @@ static int disarm_all_kprobes(void) >> return ret; >> } >> >> -/* >> - * XXX: The debugfs bool file interface doesn't allow for callbacks >> - * when the bool state is switched. We can reuse that facility when >> - * available >> - */ >> -static ssize_t read_enabled_file_bool(struct file *file, >> - char __user *user_buf, size_t count, loff_t *ppos) >> +static int kprobes_enabled_set(void *data, u64 val) >> { >> - char buf[3]; >> + if (val) >> + return arm_all_kprobes(); >> >> - if (!kprobes_all_disarmed) >> - buf[0] = '1'; >> - else >> - buf[0] = '0'; >> - buf[1] = '\n'; >> - buf[2] = 0x00; >> - return simple_read_from_buffer(user_buf, count, ppos, buf, 2); >> + return disarm_all_kprobes(); >> } >> >> -static ssize_t write_enabled_file_bool(struct file *file, >> - const char __user *user_buf, size_t count, loff_t *ppos) >> +static int kprobes_enabled_get(void *data, u64 *val) >> { >> - bool enable; >> - int ret; >> - >> - ret = kstrtobool_from_user(user_buf, count, &enable); >> - if (ret) >> - return ret; >> - >> - ret = enable ? arm_all_kprobes() : disarm_all_kprobes(); >> - if (ret) >> - return ret; >> - >> - return count; >> + *val = !kprobes_all_disarmed; >> + return 0; >> } >> >> -static const struct file_operations fops_kp = { >> - .read = read_enabled_file_bool, >> - .write = write_enabled_file_bool, >> - .llseek = default_llseek, >> -}; >> +DEFINE_DEBUGFS_ATTRIBUTE(fops_kp, kprobes_enabled_get, >> + kprobes_enabled_set, "%llu\n"); >> >> static int __init debugfs_kprobe_init(void) >> { >> -- >> 2.47.3 >> > > > Thanks! ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] kprobes: use DEFINE_DEBUGFS_ATTRIBUTE for the enabled knob 2026-08-18 23:12 ` Bradley Morgan @ 2026-08-20 15:14 ` Bradley Morgan 2026-08-21 1:56 ` Masami Hiramatsu 0 siblings, 1 reply; 6+ messages in thread From: Bradley Morgan @ 2026-08-20 15:14 UTC (permalink / raw) To: Masami Hiramatsu Cc: Naveen N Rao, David S . Miller, linux-kernel, linux-trace-kernel On 19 August 2026 00:12:40 BST, Bradley Morgan <include@grrlz.net> wrote: >On 19 August 2026 00:08:13 BST, Masami Hiramatsu <mhiramat@kernel.org> >wrote: >>On Tue, 18 Aug 2026 01:53:18 +0000 >>Bradley Morgan <include@grrlz.net> wrote: >> >>> This enabled knob is a disgusting terrible hack. It has rolled its >>> own read/write pair since 2007, writing '1' or '0' into a three byte >>> buffer by hand just to print a single character, with an XXX comment >>> begging debugfs for write callbacks on bool files. >>> DEFINE_DEBUGFS_ATTRIBUTE showed up in 2016 and does exactly that, so >>> the disgusting terrible hack has outlived its excuse for nine years. >>> Kill it, and the stale comment with it. >> >>In other words, does this mean something like the following? >> >>This "enable" knob implemented custom read/write logic, manually writing >>"1" or "0" to a 3-byte buffer solely to output a single character. As >>suggested by comments calling for `debugfs` to support write callbacks >>for boolean files, using `DEFINE_DEBUGFS_ATTRIBUTE` eliminates the need >>for these callbacks. >> > >ehhhhh, well, my description very well tells someone about why this is >bad, and a hack, and everything. > >Your description is good though... But I love to have my personality in my >descriptions :( > Masami, could you give a round down of your nits for V3? > >>Thanks, >> >>> >>> The behavior does not change, except the write only accepts 0/1 now >>> instead of y/n/on/off, and nothing uses anything else. >>> >>> Signed-off-by: Bradley Morgan <include@grrlz.net> >>> --- >>> Changes since v1: >>> - Added the missing Signed-off-by, sorry. >>> >>> kernel/kprobes.c | 43 +++++++++---------------------------------- >>> 1 file changed, 9 insertions(+), 34 deletions(-) >>> >>> diff --git a/kernel/kprobes.c b/kernel/kprobes.c >>> index bfc89083daa9..044c6b5fd2aa 100644 >>> --- a/kernel/kprobes.c >>> +++ b/kernel/kprobes.c >>> @@ -3013,47 +3013,22 @@ static int disarm_all_kprobes(void) >>> return ret; >>> } >>> >>> -/* >>> - * XXX: The debugfs bool file interface doesn't allow for callbacks >>> - * when the bool state is switched. We can reuse that facility when >>> - * available >>> - */ >>> -static ssize_t read_enabled_file_bool(struct file *file, >>> - char __user *user_buf, size_t count, loff_t *ppos) >>> +static int kprobes_enabled_set(void *data, u64 val) >>> { >>> - char buf[3]; >>> + if (val) >>> + return arm_all_kprobes(); >>> >>> - if (!kprobes_all_disarmed) >>> - buf[0] = '1'; >>> - else >>> - buf[0] = '0'; >>> - buf[1] = '\n'; >>> - buf[2] = 0x00; >>> - return simple_read_from_buffer(user_buf, count, ppos, buf, 2); >>> + return disarm_all_kprobes(); >>> } >>> >>> -static ssize_t write_enabled_file_bool(struct file *file, >>> - const char __user *user_buf, size_t count, loff_t *ppos) >>> +static int kprobes_enabled_get(void *data, u64 *val) >>> { >>> - bool enable; >>> - int ret; >>> - >>> - ret = kstrtobool_from_user(user_buf, count, &enable); >>> - if (ret) >>> - return ret; >>> - >>> - ret = enable ? arm_all_kprobes() : disarm_all_kprobes(); >>> - if (ret) >>> - return ret; >>> - >>> - return count; >>> + *val = !kprobes_all_disarmed; >>> + return 0; >>> } >>> >>> -static const struct file_operations fops_kp = { >>> - .read = read_enabled_file_bool, >>> - .write = write_enabled_file_bool, >>> - .llseek = default_llseek, >>> -}; >>> +DEFINE_DEBUGFS_ATTRIBUTE(fops_kp, kprobes_enabled_get, >>> + kprobes_enabled_set, "%llu\n"); >>> >>> static int __init debugfs_kprobe_init(void) >>> { >>> -- >>> 2.47.3 >>> >> >> >> > >Thanks! Thanks! ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] kprobes: use DEFINE_DEBUGFS_ATTRIBUTE for the enabled knob 2026-08-20 15:14 ` Bradley Morgan @ 2026-08-21 1:56 ` Masami Hiramatsu 2026-08-21 8:23 ` Bradley Morgan 0 siblings, 1 reply; 6+ messages in thread From: Masami Hiramatsu @ 2026-08-21 1:56 UTC (permalink / raw) To: Bradley Morgan Cc: Naveen N Rao, David S . Miller, linux-kernel, linux-trace-kernel On Thu, 20 Aug 2026 16:14:42 +0100 Bradley Morgan <include@grrlz.net> wrote: > On 19 August 2026 00:12:40 BST, Bradley Morgan <include@grrlz.net> wrote: > >On 19 August 2026 00:08:13 BST, Masami Hiramatsu <mhiramat@kernel.org> > >wrote: > >>On Tue, 18 Aug 2026 01:53:18 +0000 > >>Bradley Morgan <include@grrlz.net> wrote: > >> > >>> This enabled knob is a disgusting terrible hack. It has rolled its > >>> own read/write pair since 2007, writing '1' or '0' into a three byte > >>> buffer by hand just to print a single character, with an XXX comment > >>> begging debugfs for write callbacks on bool files. > >>> DEFINE_DEBUGFS_ATTRIBUTE showed up in 2016 and does exactly that, so > >>> the disgusting terrible hack has outlived its excuse for nine years. > >>> Kill it, and the stale comment with it. > >> > >>In other words, does this mean something like the following? > >> > >>This "enable" knob implemented custom read/write logic, manually writing > >>"1" or "0" to a 3-byte buffer solely to output a single character. As > >>suggested by comments calling for `debugfs` to support write callbacks > >>for boolean files, using `DEFINE_DEBUGFS_ATTRIBUTE` eliminates the need > >>for these callbacks. > >> > > > >ehhhhh, well, my description very well tells someone about why this is > >bad, and a hack, and everything. > > > >Your description is good though... But I love to have my personality in my > >descriptions :( > > > > Masami, could you give a round down of your nits for V3? Ah, OK. The phrasing aside, what you said wasn't wrong, so if you're happy with it, I'll pick it. (Let me pick it to probes/core) Thanks. > > > > > >>Thanks, > >> > >>> > >>> The behavior does not change, except the write only accepts 0/1 now > >>> instead of y/n/on/off, and nothing uses anything else. > >>> > >>> Signed-off-by: Bradley Morgan <include@grrlz.net> > >>> --- > >>> Changes since v1: > >>> - Added the missing Signed-off-by, sorry. > >>> > >>> kernel/kprobes.c | 43 +++++++++---------------------------------- > >>> 1 file changed, 9 insertions(+), 34 deletions(-) > >>> > >>> diff --git a/kernel/kprobes.c b/kernel/kprobes.c > >>> index bfc89083daa9..044c6b5fd2aa 100644 > >>> --- a/kernel/kprobes.c > >>> +++ b/kernel/kprobes.c > >>> @@ -3013,47 +3013,22 @@ static int disarm_all_kprobes(void) > >>> return ret; > >>> } > >>> > >>> -/* > >>> - * XXX: The debugfs bool file interface doesn't allow for callbacks > >>> - * when the bool state is switched. We can reuse that facility when > >>> - * available > >>> - */ > >>> -static ssize_t read_enabled_file_bool(struct file *file, > >>> - char __user *user_buf, size_t count, loff_t *ppos) > >>> +static int kprobes_enabled_set(void *data, u64 val) > >>> { > >>> - char buf[3]; > >>> + if (val) > >>> + return arm_all_kprobes(); > >>> > >>> - if (!kprobes_all_disarmed) > >>> - buf[0] = '1'; > >>> - else > >>> - buf[0] = '0'; > >>> - buf[1] = '\n'; > >>> - buf[2] = 0x00; > >>> - return simple_read_from_buffer(user_buf, count, ppos, buf, 2); > >>> + return disarm_all_kprobes(); > >>> } > >>> > >>> -static ssize_t write_enabled_file_bool(struct file *file, > >>> - const char __user *user_buf, size_t count, loff_t *ppos) > >>> +static int kprobes_enabled_get(void *data, u64 *val) > >>> { > >>> - bool enable; > >>> - int ret; > >>> - > >>> - ret = kstrtobool_from_user(user_buf, count, &enable); > >>> - if (ret) > >>> - return ret; > >>> - > >>> - ret = enable ? arm_all_kprobes() : disarm_all_kprobes(); > >>> - if (ret) > >>> - return ret; > >>> - > >>> - return count; > >>> + *val = !kprobes_all_disarmed; > >>> + return 0; > >>> } > >>> > >>> -static const struct file_operations fops_kp = { > >>> - .read = read_enabled_file_bool, > >>> - .write = write_enabled_file_bool, > >>> - .llseek = default_llseek, > >>> -}; > >>> +DEFINE_DEBUGFS_ATTRIBUTE(fops_kp, kprobes_enabled_get, > >>> + kprobes_enabled_set, "%llu\n"); > >>> > >>> static int __init debugfs_kprobe_init(void) > >>> { > >>> -- > >>> 2.47.3 > >>> > >> > >> > >> > > > >Thanks! > > Thanks! -- Masami Hiramatsu (Google) <mhiramat@kernel.org> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] kprobes: use DEFINE_DEBUGFS_ATTRIBUTE for the enabled knob 2026-08-21 1:56 ` Masami Hiramatsu @ 2026-08-21 8:23 ` Bradley Morgan 0 siblings, 0 replies; 6+ messages in thread From: Bradley Morgan @ 2026-08-21 8:23 UTC (permalink / raw) To: Masami Hiramatsu Cc: Naveen N Rao, David S . Miller, linux-kernel, linux-trace-kernel On 21 August 2026 02:56:48 BST, Masami Hiramatsu <mhiramat@kernel.org> wrote: >On Thu, 20 Aug 2026 16:14:42 +0100 >Bradley Morgan <include@grrlz.net> wrote: > >> On 19 August 2026 00:12:40 BST, Bradley Morgan <include@grrlz.net> >wrote: >> >On 19 August 2026 00:08:13 BST, Masami Hiramatsu <mhiramat@kernel.org> >> >wrote: >> >>On Tue, 18 Aug 2026 01:53:18 +0000 >> >>Bradley Morgan <include@grrlz.net> wrote: >> >> >> >>> This enabled knob is a disgusting terrible hack. It has rolled its >> >>> own read/write pair since 2007, writing '1' or '0' into a three byte >> >>> buffer by hand just to print a single character, with an XXX comment >> >>> begging debugfs for write callbacks on bool files. >> >>> DEFINE_DEBUGFS_ATTRIBUTE showed up in 2016 and does exactly that, so >> >>> the disgusting terrible hack has outlived its excuse for nine years. >> >>> Kill it, and the stale comment with it. >> >> >> >>In other words, does this mean something like the following? >> >> >> >>This "enable" knob implemented custom read/write logic, manually >writing >> >>"1" or "0" to a 3-byte buffer solely to output a single character. As >> >>suggested by comments calling for `debugfs` to support write callbacks >> >>for boolean files, using `DEFINE_DEBUGFS_ATTRIBUTE` eliminates the >need >> >>for these callbacks. >> >> >> > >> >ehhhhh, well, my description very well tells someone about why this is >> >bad, and a hack, and everything. >> > >> >Your description is good though... But I love to have my personality in >my >> >descriptions :( >> > >> >> Masami, could you give a round down of your nits for V3? > >Ah, OK. The phrasing aside, what you said wasn't wrong, so if you're happy >with it, I'll pick it. (Let me pick it to probes/core) > I'm happy with this patch as is, how accurate? Do the roar! (Pick it, Shrek reference) >Thanks. > > > >> >> >> > >> >>Thanks, >> >> >> >>> >> >>> The behavior does not change, except the write only accepts 0/1 now >> >>> instead of y/n/on/off, and nothing uses anything else. >> >>> >> >>> Signed-off-by: Bradley Morgan <include@grrlz.net> >> >>> --- >> >>> Changes since v1: >> >>> - Added the missing Signed-off-by, sorry. >> >>> >> >>> kernel/kprobes.c | 43 +++++++++---------------------------------- >> >>> 1 file changed, 9 insertions(+), 34 deletions(-) >> >>> >> >>> diff --git a/kernel/kprobes.c b/kernel/kprobes.c >> >>> index bfc89083daa9..044c6b5fd2aa 100644 >> >>> --- a/kernel/kprobes.c >> >>> +++ b/kernel/kprobes.c >> >>> @@ -3013,47 +3013,22 @@ static int disarm_all_kprobes(void) >> >>> return ret; >> >>> } >> >>> >> >>> -/* >> >>> - * XXX: The debugfs bool file interface doesn't allow for callbacks >> >>> - * when the bool state is switched. We can reuse that facility when >> >>> - * available >> >>> - */ >> >>> -static ssize_t read_enabled_file_bool(struct file *file, >> >>> - char __user *user_buf, size_t count, loff_t *ppos) >> >>> +static int kprobes_enabled_set(void *data, u64 val) >> >>> { >> >>> - char buf[3]; >> >>> + if (val) >> >>> + return arm_all_kprobes(); >> >>> >> >>> - if (!kprobes_all_disarmed) >> >>> - buf[0] = '1'; >> >>> - else >> >>> - buf[0] = '0'; >> >>> - buf[1] = '\n'; >> >>> - buf[2] = 0x00; >> >>> - return simple_read_from_buffer(user_buf, count, ppos, buf, 2); >> >>> + return disarm_all_kprobes(); >> >>> } >> >>> >> >>> -static ssize_t write_enabled_file_bool(struct file *file, >> >>> - const char __user *user_buf, size_t count, loff_t *ppos) >> >>> +static int kprobes_enabled_get(void *data, u64 *val) >> >>> { >> >>> - bool enable; >> >>> - int ret; >> >>> - >> >>> - ret = kstrtobool_from_user(user_buf, count, &enable); >> >>> - if (ret) >> >>> - return ret; >> >>> - >> >>> - ret = enable ? arm_all_kprobes() : disarm_all_kprobes(); >> >>> - if (ret) >> >>> - return ret; >> >>> - >> >>> - return count; >> >>> + *val = !kprobes_all_disarmed; >> >>> + return 0; >> >>> } >> >>> >> >>> -static const struct file_operations fops_kp = { >> >>> - .read = read_enabled_file_bool, >> >>> - .write = write_enabled_file_bool, >> >>> - .llseek = default_llseek, >> >>> -}; >> >>> +DEFINE_DEBUGFS_ATTRIBUTE(fops_kp, kprobes_enabled_get, >> >>> + kprobes_enabled_set, "%llu\n"); >> >>> >> >>> static int __init debugfs_kprobe_init(void) >> >>> { >> >>> -- >> >>> 2.47.3 >> >>> >> >> >> >> >> >> >> > >> >Thanks! >> >> Thanks! > > > Thanks! ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-08-21 8:23 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2026-08-18 1:53 [PATCH v2] kprobes: use DEFINE_DEBUGFS_ATTRIBUTE for the enabled knob Bradley Morgan 2026-08-18 23:08 ` Masami Hiramatsu 2026-08-18 23:12 ` Bradley Morgan 2026-08-20 15:14 ` Bradley Morgan 2026-08-21 1:56 ` Masami Hiramatsu 2026-08-21 8:23 ` Bradley Morgan
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