Commit be7635e7 authored by Alexander Potapenko's avatar Alexander Potapenko Committed by Linus Torvalds

arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections

KASAN needs to know whether the allocation happens in an IRQ handler.
This lets us strip everything below the IRQ entry point to reduce the
number of unique stack traces needed to be stored.

Move the definition of __irq_entry to <linux/interrupt.h> so that the
users don't need to pull in <linux/ftrace.h>.  Also introduce the
__softirq_entry macro which is similar to __irq_entry, but puts the
corresponding functions to the .softirqentry.text section.
Signed-off-by: default avatarAlexander Potapenko <glider@google.com>
Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 505f5dcb
......@@ -7,7 +7,7 @@
#ifndef __ASM_ARM_EXCEPTION_H
#define __ASM_ARM_EXCEPTION_H
#include <linux/ftrace.h>
#include <linux/interrupt.h>
#define __exception __attribute__((section(".exception.text")))
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
......
......@@ -108,6 +108,7 @@ SECTIONS
*(.exception.text)
__exception_text_end = .;
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT
......
......@@ -18,7 +18,7 @@
#ifndef __ASM_EXCEPTION_H
#define __ASM_EXCEPTION_H
#include <linux/ftrace.h>
#include <linux/interrupt.h>
#define __exception __attribute__((section(".exception.text")))
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
......
......@@ -103,6 +103,7 @@ SECTIONS
*(.exception.text)
__exception_text_end = .;
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT
......
......@@ -35,6 +35,7 @@ SECTIONS
#endif
LOCK_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
KPROBES_TEXT
#ifdef CONFIG_ROMKERNEL
__sinittext = .;
......
......@@ -72,6 +72,7 @@ SECTIONS
SCHED_TEXT
LOCK_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
KPROBES_TEXT
*(.fixup)
*(.gnu.warning)
......
......@@ -24,6 +24,7 @@ SECTIONS
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
*(.text.*)
*(.gnu.warning)
}
......
......@@ -36,6 +36,7 @@ SECTIONS {
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
. = ALIGN (4) ;
_etext = . ;
}
......
......@@ -58,6 +58,7 @@ SECTIONS
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
*(.text.*)
*(.fixup)
*(.gnu.warning)
......
......@@ -39,6 +39,7 @@ SECTIONS
SCHED_TEXT
LOCK_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
KPROBES_TEXT
} =0
_etext = .;
......
......@@ -50,6 +50,7 @@ SECTIONS
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
*(.fixup)
*(.text.__*)
_etext = .;
......
......@@ -72,6 +72,7 @@ SECTIONS
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
*(.text.do_softirq)
*(.text.sys_exit)
*(.text.do_sigaltstack)
......
......@@ -55,6 +55,7 @@ SECTIONS
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
#ifdef CONFIG_PPC32
*(.got1)
......
......@@ -28,6 +28,7 @@ SECTIONS
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
*(.fixup)
*(.gnu.warning)
} :text = 0x0700
......
......@@ -39,6 +39,7 @@ SECTIONS
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
*(.fixup)
*(.gnu.warning)
_etext = .; /* End of text section */
......
......@@ -48,6 +48,7 @@ SECTIONS
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
*(.gnu.warning)
} = 0
_etext = .;
......
......@@ -45,6 +45,7 @@ SECTIONS
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
__fix_text_end = .; /* tile-cpack won't rearrange before this */
ALIGN_FUNCTION();
*(.hottext*)
......
......@@ -101,6 +101,7 @@ SECTIONS
KPROBES_TEXT
ENTRY_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
*(.fixup)
*(.gnu.warning)
/* End of text section */
......
......@@ -456,7 +456,7 @@
*(.entry.text) \
VMLINUX_SYMBOL(__entry_text_end) = .;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
#define IRQENTRY_TEXT \
ALIGN_FUNCTION(); \
VMLINUX_SYMBOL(__irqentry_text_start) = .; \
......@@ -466,6 +466,16 @@
#define IRQENTRY_TEXT
#endif
#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
#define SOFTIRQENTRY_TEXT \
ALIGN_FUNCTION(); \
VMLINUX_SYMBOL(__softirqentry_text_start) = .; \
*(.softirqentry.text) \
VMLINUX_SYMBOL(__softirqentry_text_end) = .;
#else
#define SOFTIRQENTRY_TEXT
#endif
/* Section used for early init (in .S files) */
#define HEAD_TEXT *(.head.text)
......
......@@ -811,16 +811,6 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
*/
#define __notrace_funcgraph notrace
/*
* We want to which function is an entrypoint of a hardirq.
* That will help us to put a signal on output.
*/
#define __irq_entry __attribute__((__section__(".irqentry.text")))
/* Limits of hardirq entrypoints */
extern char __irqentry_text_start[];
extern char __irqentry_text_end[];
#define FTRACE_NOTRACE_DEPTH 65536
#define FTRACE_RETFUNC_DEPTH 50
#define FTRACE_RETSTACK_ALLOC_SIZE 32
......@@ -857,7 +847,6 @@ static inline void unpause_graph_tracing(void)
#else /* !CONFIG_FUNCTION_GRAPH_TRACER */
#define __notrace_funcgraph
#define __irq_entry
#define INIT_FTRACE_GRAPH
static inline void ftrace_graph_init_task(struct task_struct *t) { }
......
......@@ -683,4 +683,24 @@ extern int early_irq_init(void);
extern int arch_probe_nr_irqs(void);
extern int arch_early_irq_init(void);
#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
/*
* We want to know which function is an entrypoint of a hardirq or a softirq.
*/
#define __irq_entry __attribute__((__section__(".irqentry.text")))
#define __softirq_entry \
__attribute__((__section__(".softirqentry.text")))
/* Limits of hardirq entrypoints */
extern char __irqentry_text_start[];
extern char __irqentry_text_end[];
/* Limits of softirq entrypoints */
extern char __softirqentry_text_start[];
extern char __softirqentry_text_end[];
#else
#define __irq_entry
#define __softirq_entry
#endif
#endif
......@@ -227,7 +227,7 @@ static inline bool lockdep_softirq_start(void) { return false; }
static inline void lockdep_softirq_end(bool in_hardirq) { }
#endif
asmlinkage __visible void __do_softirq(void)
asmlinkage __visible void __softirq_entry __do_softirq(void)
{
unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
unsigned long old_flags = current->flags;
......
......@@ -8,6 +8,7 @@
*/
#include <linux/uaccess.h>
#include <linux/ftrace.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/fs.h>
......
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