Several run-time checkers (KASAN, UBSAN, KFENCE, KCSAN, sched) roll
their own warnings, and each check "panic_on_warn". Consolidate this
into a single function so that future instrumentation can be added in
a single location.
Cc: Marco Elver <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Vincent Guittot <[email protected]>
Cc: Dietmar Eggemann <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Ben Segall <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Daniel Bristot de Oliveira <[email protected]>
Cc: Valentin Schneider <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Luis Chamberlain <[email protected]>
Cc: David Gow <[email protected]>
Cc: tangmeng <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: "Guilherme G. Piccoli" <[email protected]>
Cc: Tiezhu Yang <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
include/linux/panic.h | 1 +
kernel/kcsan/report.c | 3 +--
kernel/panic.c | 9 +++++++--
kernel/sched/core.c | 3 +--
lib/ubsan.c | 3 +--
mm/kasan/report.c | 4 ++--
mm/kfence/report.c | 3 +--
7 files changed, 14 insertions(+), 12 deletions(-)
diff --git a/include/linux/panic.h b/include/linux/panic.h
index c7759b3f2045..1702aeb74927 100644
--- a/include/linux/panic.h
+++ b/include/linux/panic.h
@@ -11,6 +11,7 @@ extern long (*panic_blink)(int state);
__printf(1, 2)
void panic(const char *fmt, ...) __noreturn __cold;
void nmi_panic(struct pt_regs *regs, const char *msg);
+void check_panic_on_warn(const char *reason);
extern void oops_enter(void);
extern void oops_exit(void);
extern bool oops_may_print(void);
diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c
index 67794404042a..e95ce7d7a76e 100644
--- a/kernel/kcsan/report.c
+++ b/kernel/kcsan/report.c
@@ -492,8 +492,7 @@ static void print_report(enum kcsan_value_change value_change,
dump_stack_print_info(KERN_DEFAULT);
pr_err("==================================================================\n");
- if (panic_on_warn)
- panic("panic_on_warn set ...\n");
+ check_panic_on_warn("KCSAN");
}
static void release_report(unsigned long *flags, struct other_info *other_info)
diff --git a/kernel/panic.c b/kernel/panic.c
index 129936511380..3afd234767bc 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -201,6 +201,12 @@ static void panic_print_sys_info(bool console_flush)
ftrace_dump(DUMP_ALL);
}
+void check_panic_on_warn(const char *reason)
+{
+ if (panic_on_warn)
+ panic("%s: panic_on_warn set ...\n", reason);
+}
+
/**
* panic - halt the system
* @fmt: The text string to print
@@ -619,8 +625,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
if (regs)
show_regs(regs);
- if (panic_on_warn)
- panic("panic_on_warn set ...\n");
+ check_panic_on_warn("kernel");
if (!regs)
dump_stack();
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5800b0623ff3..285ef8821b4f 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5729,8 +5729,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
pr_err("Preemption disabled at:");
print_ip_sym(KERN_ERR, preempt_disable_ip);
}
- if (panic_on_warn)
- panic("scheduling while atomic\n");
+ check_panic_on_warn("scheduling while atomic");
dump_stack();
add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
diff --git a/lib/ubsan.c b/lib/ubsan.c
index 36bd75e33426..60c7099857a0 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -154,8 +154,7 @@ static void ubsan_epilogue(void)
current->in_ubsan--;
- if (panic_on_warn)
- panic("panic_on_warn set ...\n");
+ check_panic_on_warn("UBSAN");
}
void __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs)
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index df3602062bfd..cc98dfdd3ed2 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -164,8 +164,8 @@ static void end_report(unsigned long *flags, void *addr)
(unsigned long)addr);
pr_err("==================================================================\n");
spin_unlock_irqrestore(&report_lock, *flags);
- if (panic_on_warn && !test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))
- panic("panic_on_warn set ...\n");
+ if (!test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))
+ check_panic_on_warn("KASAN");
if (kasan_arg_fault == KASAN_ARG_FAULT_PANIC)
panic("kasan.fault=panic set ...\n");
add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
diff --git a/mm/kfence/report.c b/mm/kfence/report.c
index 7e496856c2eb..110c27ca597d 100644
--- a/mm/kfence/report.c
+++ b/mm/kfence/report.c
@@ -268,8 +268,7 @@ void kfence_report_error(unsigned long address, bool is_write, struct pt_regs *r
lockdep_on();
- if (panic_on_warn)
- panic("panic_on_warn set ...\n");
+ check_panic_on_warn("KFENCE");
/* We encountered a memory safety error, taint the kernel! */
add_taint(TAINT_BAD_PAGE, LOCKDEP_STILL_OK);
--
2.34.1
On Wed, 9 Nov 2022 at 21:00, Kees Cook <[email protected]> wrote:
>
> Several run-time checkers (KASAN, UBSAN, KFENCE, KCSAN, sched) roll
> their own warnings, and each check "panic_on_warn". Consolidate this
> into a single function so that future instrumentation can be added in
> a single location.
>
> Cc: Marco Elver <[email protected]>
> Cc: Dmitry Vyukov <[email protected]>
> Cc: Peter Zijlstra <[email protected]>
> Cc: Juri Lelli <[email protected]>
> Cc: Vincent Guittot <[email protected]>
> Cc: Dietmar Eggemann <[email protected]>
> Cc: Steven Rostedt <[email protected]>
> Cc: Ben Segall <[email protected]>
> Cc: Mel Gorman <[email protected]>
> Cc: Daniel Bristot de Oliveira <[email protected]>
> Cc: Valentin Schneider <[email protected]>
> Cc: Andrey Ryabinin <[email protected]>
> Cc: Alexander Potapenko <[email protected]>
> Cc: Andrey Konovalov <[email protected]>
> Cc: Vincenzo Frascino <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: Luis Chamberlain <[email protected]>
> Cc: David Gow <[email protected]>
> Cc: tangmeng <[email protected]>
> Cc: Jann Horn <[email protected]>
> Cc: Petr Mladek <[email protected]>
> Cc: "Paul E. McKenney" <[email protected]>
> Cc: Sebastian Andrzej Siewior <[email protected]>
> Cc: "Guilherme G. Piccoli" <[email protected]>
> Cc: Tiezhu Yang <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
> ---
> include/linux/panic.h | 1 +
> kernel/kcsan/report.c | 3 +--
> kernel/panic.c | 9 +++++++--
> kernel/sched/core.c | 3 +--
> lib/ubsan.c | 3 +--
> mm/kasan/report.c | 4 ++--
> mm/kfence/report.c | 3 +--
> 7 files changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/include/linux/panic.h b/include/linux/panic.h
> index c7759b3f2045..1702aeb74927 100644
> --- a/include/linux/panic.h
> +++ b/include/linux/panic.h
> @@ -11,6 +11,7 @@ extern long (*panic_blink)(int state);
> __printf(1, 2)
> void panic(const char *fmt, ...) __noreturn __cold;
> void nmi_panic(struct pt_regs *regs, const char *msg);
> +void check_panic_on_warn(const char *reason);
> extern void oops_enter(void);
> extern void oops_exit(void);
> extern bool oops_may_print(void);
> diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c
> index 67794404042a..e95ce7d7a76e 100644
> --- a/kernel/kcsan/report.c
> +++ b/kernel/kcsan/report.c
> @@ -492,8 +492,7 @@ static void print_report(enum kcsan_value_change value_change,
> dump_stack_print_info(KERN_DEFAULT);
> pr_err("==================================================================\n");
>
> - if (panic_on_warn)
> - panic("panic_on_warn set ...\n");
> + check_panic_on_warn("KCSAN");
> }
>
> static void release_report(unsigned long *flags, struct other_info *other_info)
> diff --git a/kernel/panic.c b/kernel/panic.c
> index 129936511380..3afd234767bc 100644
> --- a/kernel/panic.c
> +++ b/kernel/panic.c
> @@ -201,6 +201,12 @@ static void panic_print_sys_info(bool console_flush)
> ftrace_dump(DUMP_ALL);
> }
>
> +void check_panic_on_warn(const char *reason)
> +{
> + if (panic_on_warn)
> + panic("%s: panic_on_warn set ...\n", reason);
> +}
> +
> /**
> * panic - halt the system
> * @fmt: The text string to print
> @@ -619,8 +625,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
> if (regs)
> show_regs(regs);
>
> - if (panic_on_warn)
> - panic("panic_on_warn set ...\n");
> + check_panic_on_warn("kernel");
What is the reason "kernel" in this context? The real reason is a WARN
- so would the reason "WARNING" be more intuitive?
On Mon, Nov 14, 2022 at 10:57:15AM +0100, Marco Elver wrote:
> On Wed, 9 Nov 2022 at 21:00, Kees Cook <[email protected]> wrote:
> >
> > Several run-time checkers (KASAN, UBSAN, KFENCE, KCSAN, sched) roll
> > their own warnings, and each check "panic_on_warn". Consolidate this
> > into a single function so that future instrumentation can be added in
> > a single location.
> >
> > Cc: Marco Elver <[email protected]>
> > Cc: Dmitry Vyukov <[email protected]>
> > Cc: Peter Zijlstra <[email protected]>
> > Cc: Juri Lelli <[email protected]>
> > Cc: Vincent Guittot <[email protected]>
> > Cc: Dietmar Eggemann <[email protected]>
> > Cc: Steven Rostedt <[email protected]>
> > Cc: Ben Segall <[email protected]>
> > Cc: Mel Gorman <[email protected]>
> > Cc: Daniel Bristot de Oliveira <[email protected]>
> > Cc: Valentin Schneider <[email protected]>
> > Cc: Andrey Ryabinin <[email protected]>
> > Cc: Alexander Potapenko <[email protected]>
> > Cc: Andrey Konovalov <[email protected]>
> > Cc: Vincenzo Frascino <[email protected]>
> > Cc: Andrew Morton <[email protected]>
> > Cc: Luis Chamberlain <[email protected]>
> > Cc: David Gow <[email protected]>
> > Cc: tangmeng <[email protected]>
> > Cc: Jann Horn <[email protected]>
> > Cc: Petr Mladek <[email protected]>
> > Cc: "Paul E. McKenney" <[email protected]>
> > Cc: Sebastian Andrzej Siewior <[email protected]>
> > Cc: "Guilherme G. Piccoli" <[email protected]>
> > Cc: Tiezhu Yang <[email protected]>
> > Cc: [email protected]
> > Cc: [email protected]
> > Signed-off-by: Kees Cook <[email protected]>
> > ---
> > include/linux/panic.h | 1 +
> > kernel/kcsan/report.c | 3 +--
> > kernel/panic.c | 9 +++++++--
> > kernel/sched/core.c | 3 +--
> > lib/ubsan.c | 3 +--
> > mm/kasan/report.c | 4 ++--
> > mm/kfence/report.c | 3 +--
> > 7 files changed, 14 insertions(+), 12 deletions(-)
> >
> > diff --git a/include/linux/panic.h b/include/linux/panic.h
> > index c7759b3f2045..1702aeb74927 100644
> > --- a/include/linux/panic.h
> > +++ b/include/linux/panic.h
> > @@ -11,6 +11,7 @@ extern long (*panic_blink)(int state);
> > __printf(1, 2)
> > void panic(const char *fmt, ...) __noreturn __cold;
> > void nmi_panic(struct pt_regs *regs, const char *msg);
> > +void check_panic_on_warn(const char *reason);
> > extern void oops_enter(void);
> > extern void oops_exit(void);
> > extern bool oops_may_print(void);
> > diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c
> > index 67794404042a..e95ce7d7a76e 100644
> > --- a/kernel/kcsan/report.c
> > +++ b/kernel/kcsan/report.c
> > @@ -492,8 +492,7 @@ static void print_report(enum kcsan_value_change value_change,
> > dump_stack_print_info(KERN_DEFAULT);
> > pr_err("==================================================================\n");
> >
> > - if (panic_on_warn)
> > - panic("panic_on_warn set ...\n");
> > + check_panic_on_warn("KCSAN");
> > }
> >
> > static void release_report(unsigned long *flags, struct other_info *other_info)
> > diff --git a/kernel/panic.c b/kernel/panic.c
> > index 129936511380..3afd234767bc 100644
> > --- a/kernel/panic.c
> > +++ b/kernel/panic.c
> > @@ -201,6 +201,12 @@ static void panic_print_sys_info(bool console_flush)
> > ftrace_dump(DUMP_ALL);
> > }
> >
> > +void check_panic_on_warn(const char *reason)
> > +{
> > + if (panic_on_warn)
> > + panic("%s: panic_on_warn set ...\n", reason);
> > +}
> > +
> > /**
> > * panic - halt the system
> > * @fmt: The text string to print
> > @@ -619,8 +625,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
> > if (regs)
> > show_regs(regs);
> >
> > - if (panic_on_warn)
> > - panic("panic_on_warn set ...\n");
> > + check_panic_on_warn("kernel");
>
> What is the reason "kernel" in this context? The real reason is a WARN
> - so would the reason "WARNING" be more intuitive?
I'll rename "reason" to "origin" or something -- it's mainly to see
who was calling this when it's not core kernel logic.
--
Kees Cook