* [PATCH] (3/4) stack updates for x86
@ 2002-12-09 22:09 Dave Hansen
0 siblings, 0 replies; 2+ messages in thread
From: Dave Hansen @ 2002-12-09 22:09 UTC (permalink / raw)
To: benh; +Cc: Arjan van de Ven, Linux Kernel Mailing List
[-- Attachment #1: Type: text/plain, Size: 284 bytes --]
The kernel currently uses an 8k stack, per task. Here is the
infrastructure needed to allow us to halve that.
C-stack_usage_check-2.5.50+bk-5.patch
Check for stack overflows on entry to each funtion. Use gcc's
-p profiling feature to do it.
--
Dave Hansen
haveblue@us.ibm.com
[-- Attachment #2: C-stack_usage_check-2.5.50+bk-5.patch --]
[-- Type: text/plain, Size: 7048 bytes --]
# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
# ChangeSet 1.860 -> 1.863
# arch/i386/kernel/process.c 1.32.1.3 -> 1.38
# arch/i386/kernel/irq.c 1.23.1.2 -> 1.26
# Makefile 1.326.2.29 -> 1.333
# include/asm-i386/thread_info.h 1.10.1.1 -> 1.13
# arch/i386/Kconfig 1.14 -> 1.15
# arch/i386/kernel/entry.S 1.38.1.6 -> 1.49
# arch/i386/Makefile 1.24.2.7 -> 1.30
# arch/i386/boot/compressed/misc.c 1.9 -> 1.10
# arch/i386/kernel/init_task.c 1.6.1.1 -> 1.8
# arch/i386/kernel/i386_ksyms.c 1.36.2.4 -> 1.41
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/12/09 haveblue@elm3b96.(none) 1.797.163.2
# Kconfig:
# update stack overflow detection for new config system
# --------------------------------------------
# 02/12/09 haveblue@elm3b96.(none) 1.859.1.1
# merge
# --------------------------------------------
# 02/12/09 haveblue@elm3b96.(none) 1.797.162.3
# merge
# --------------------------------------------
# 02/12/09 haveblue@elm3b96.(none) 1.861
# merge
# --------------------------------------------
# 02/12/09 haveblue@elm3b96.(none) 1.862
# Merge elm3b96.(none):/work/dave/bk/linux-2.5-overflow-detect
# into elm3b96.(none):/work/dave/bk/linux-2.5-irq-stack+overflow-detect
# --------------------------------------------
# 02/12/09 haveblue@elm3b96.(none) 1.863
# Makefile:
# fix merge problem
# f
# --------------------------------------------
#
diff -Nru a/arch/i386/Kconfig b/arch/i386/Kconfig
--- a/arch/i386/Kconfig Mon Dec 9 11:09:40 2002
+++ b/arch/i386/Kconfig Mon Dec 9 11:09:40 2002
@@ -1628,6 +1628,25 @@
If you don't debug the kernel, you can say N, but we may not be able
to solve problems without frame pointers.
+config X86_STACK_CHECK
+ bool "Detect stack overflows"
+ depends on FRAME_POINTER
+ help
+ Say Y here to have the kernel attempt to detect when the per-task
+ kernel stack overflows. This is much more robust checking than
+ the above overflow check, which will only occasionally detect
+ an overflow. The level of guarantee here is much greater.
+
+ Some older versions of gcc don't handle the -p option correctly.
+ Kernprof is affected by the same problem, which is described here:
+ http://oss.sgi.com/projects/kernprof/faq.html#Q9
+
+ Basically, if you get oopses in __free_pages_ok during boot when
+ you have this turned on, you need to fix gcc. The Redhat 2.96
+ version and gcc-3.x seem to work.
+
+ If not debugging a stack overflow problem, say N
+
config X86_EXTRA_IRQS
bool
depends on X86_LOCAL_APIC
diff -Nru a/arch/i386/Makefile b/arch/i386/Makefile
--- a/arch/i386/Makefile Mon Dec 9 11:09:40 2002
+++ b/arch/i386/Makefile Mon Dec 9 11:09:40 2002
@@ -52,6 +52,10 @@
MACHINE := mach-generic
endif
+ifdef CONFIG_X86_STACK_CHECK
+CFLAGS += -p
+endif
+
HEAD := arch/i386/kernel/head.o arch/i386/kernel/init_task.o
libs-y += arch/i386/lib/
diff -Nru a/arch/i386/boot/compressed/misc.c b/arch/i386/boot/compressed/misc.c
--- a/arch/i386/boot/compressed/misc.c Mon Dec 9 11:09:40 2002
+++ b/arch/i386/boot/compressed/misc.c Mon Dec 9 11:09:40 2002
@@ -377,3 +377,7 @@
if (high_loaded) close_output_buffer_if_we_run_high(mv);
return high_loaded;
}
+
+/* We don't actually check for stack overflows this early. */
+__asm__(".globl mcount ; mcount: ret\n");
+
diff -Nru a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
--- a/arch/i386/kernel/entry.S Mon Dec 9 11:09:40 2002
+++ b/arch/i386/kernel/entry.S Mon Dec 9 11:09:40 2002
@@ -520,6 +520,61 @@
pushl $do_spurious_interrupt_bug
jmp error_code
+
+#ifdef CONFIG_X86_STACK_CHECK
+.data
+ .globl stack_overflowed
+stack_overflowed:
+ .long 0
+.text
+
+ENTRY(mcount)
+ push %eax
+ movl $(THREAD_SIZE - 1),%eax
+ andl %esp,%eax
+ cmpl $STACK_WARN,%eax /* more than half the stack is used*/
+ jle 1f
+2:
+ popl %eax
+ ret
+1:
+ lock; btsl $0,stack_overflowed
+ jc 2b
+
+ # switch to overflow stack
+ movl %esp,%eax
+ movl $(stack_overflow_stack + THREAD_SIZE - 4),%esp
+
+ pushf
+ cli
+ pushl %eax
+
+ # push eip then esp of error for stack_overflow_panic
+ pushl 4(%eax)
+ pushl %eax
+
+ # update the task pointer and cpu in the overflow stack's thread_info.
+ GET_THREAD_INFO_WITH_ESP(%eax)
+ movl TI_TASK(%eax),%ebx
+ movl %ebx,stack_overflow_stack+TI_TASK
+ movl TI_CPU(%eax),%ebx
+ movl %ebx,stack_overflow_stack+TI_CPU
+
+ call stack_overflow
+
+ # pop off call arguments
+ addl $8,%esp
+
+ popl %eax
+ popf
+ movl %eax,%esp
+ popl %eax
+ movl $0,stack_overflowed
+ ret
+
+#warning stack check enabled
+#endif
+
.data
ENTRY(sys_call_table)
.long sys_restart_syscall /* 0 - old "setup()" system call, used for restarting */
diff -Nru a/arch/i386/kernel/i386_ksyms.c b/arch/i386/kernel/i386_ksyms.c
--- a/arch/i386/kernel/i386_ksyms.c Mon Dec 9 11:09:40 2002
+++ b/arch/i386/kernel/i386_ksyms.c Mon Dec 9 11:09:40 2002
@@ -216,3 +216,8 @@
EXPORT_SYMBOL(edd);
EXPORT_SYMBOL(eddnr);
#endif
+
+#ifdef CONFIG_X86_STACK_CHECK
+extern void mcount(void);
+EXPORT_SYMBOL(mcount);
+#endif
diff -Nru a/arch/i386/kernel/init_task.c b/arch/i386/kernel/init_task.c
--- a/arch/i386/kernel/init_task.c Mon Dec 9 11:09:40 2002
+++ b/arch/i386/kernel/init_task.c Mon Dec 9 11:09:40 2002
@@ -16,6 +16,10 @@
union thread_union init_irq_union
__attribute__((__section__(".data.init_task")));
+#ifdef CONFIG_X86_STACK_CHECK
+union thread_union stack_overflow_stack
+ __attribute__((__section__(".data.init_task")));
+#endif
/*
* Initial thread structure.
diff -Nru a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
--- a/arch/i386/kernel/process.c Mon Dec 9 11:09:40 2002
+++ b/arch/i386/kernel/process.c Mon Dec 9 11:09:40 2002
@@ -158,7 +158,25 @@
__setup("idle=", idle_setup);
-void show_regs(struct pt_regs * regs)
+void stack_overflow(unsigned long esp, unsigned long eip)
+{
+ int panicing = ((esp&(THREAD_SIZE-1)) <= STACK_PANIC);
+
+ printk( "esp: 0x%x masked: 0x%x STACK_PANIC:0x%x %d %d\n",
+ esp, (esp&(THREAD_SIZE-1)), STACK_PANIC, (((esp&(THREAD_SIZE-1)) <= STACK_PANIC)), panicing );
+
+ if (panicing)
+ print_symbol("stack overflow from %s\n", eip);
+ else
+ print_symbol("excessive stack use from %s\n", eip);
+ printk("esp: %p\n", (void*)esp);
+ show_trace((void*)esp);
+
+ if (panicing)
+ panic("stack overflow\n");
+}
+
+asmlinkage void show_regs(struct pt_regs * regs)
{
unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
diff -Nru a/include/asm-i386/thread_info.h b/include/asm-i386/thread_info.h
--- a/include/asm-i386/thread_info.h Mon Dec 9 11:09:40 2002
+++ b/include/asm-i386/thread_info.h Mon Dec 9 11:09:40 2002
@@ -63,6 +63,8 @@
*/
#define THREAD_ORDER 1
#define INIT_THREAD_SIZE THREAD_SIZE
+#define STACK_PANIC 0x200ul
+#define STACK_WARN ((THREAD_SIZE)>>1)
#ifndef __ASSEMBLY__
^ permalink raw reply [flat|nested] 2+ messages in thread
* [PATCH] (3/4) stack updates for x86
@ 2002-12-16 5:59 Dave Hansen
0 siblings, 0 replies; 2+ messages in thread
From: Dave Hansen @ 2002-12-16 5:59 UTC (permalink / raw)
To: Linus Torvalds; +Cc: Linux Kernel Mailing List
[-- Attachment #1: Type: text/plain, Size: 174 bytes --]
C-stack_usage_check-2.5.52+bk-6.patch
Check for stack overflows on entry to each funtion. Use gcc's
-p profiling feature to do it.
--
Dave Hansen
haveblue@us.ibm.com
[-- Attachment #2: C-stack_usage_check-2.5.52+bk6.patch --]
[-- Type: text/plain, Size: 6894 bytes --]
# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
# ChangeSet 1.860.1.2 -> 1.866
# arch/i386/kernel/process.c 1.32.1.3 -> 1.38
# arch/i386/kernel/irq.c 1.23.1.2 -> 1.26
# Makefile 1.344 -> 1.346
# include/asm-i386/thread_info.h 1.10.1.2 -> 1.14
# arch/i386/Kconfig 1.13 -> 1.15
# arch/i386/kernel/entry.S 1.38.1.6 -> 1.49
# arch/i386/Makefile 1.24.2.7 -> 1.30
# arch/i386/boot/compressed/misc.c 1.9 -> 1.10
# arch/i386/kernel/init_task.c 1.6.1.1 -> 1.8
# arch/i386/kernel/i386_ksyms.c 1.36.2.4 -> 1.41
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/12/15 haveblue@elm3b96.(none) 1.859.1.2
# Merge elm3b96.(none):/work/dave/bk/linux-2.5-thread_info_infra
# into elm3b96.(none):/work/dave/bk/linux-2.5-overflow-detect
# --------------------------------------------
# 02/12/15 haveblue@elm3b96.(none) 1.865
# Merge elm3b96.(none):/work/dave/bk/linux-2.5-irq-stack
# into elm3b96.(none):/work/dave/bk/linux-2.5-irq-stack+overflow-detect
# --------------------------------------------
# 02/12/15 haveblue@elm3b96.(none) 1.866
# Merge elm3b96.(none):/work/dave/bk/linux-2.5-overflow-detect
# into elm3b96.(none):/work/dave/bk/linux-2.5-irq-stack+overflow-detect
# --------------------------------------------
#
diff -Nru a/arch/i386/Kconfig b/arch/i386/Kconfig
--- a/arch/i386/Kconfig Sun Dec 15 21:16:27 2002
+++ b/arch/i386/Kconfig Sun Dec 15 21:16:27 2002
@@ -1573,6 +1573,25 @@
If you don't debug the kernel, you can say N, but we may not be able
to solve problems without frame pointers.
+config X86_STACK_CHECK
+ bool "Detect stack overflows"
+ depends on FRAME_POINTER
+ help
+ Say Y here to have the kernel attempt to detect when the per-task
+ kernel stack overflows. This is much more robust checking than
+ the above overflow check, which will only occasionally detect
+ an overflow. The level of guarantee here is much greater.
+
+ Some older versions of gcc don't handle the -p option correctly.
+ Kernprof is affected by the same problem, which is described here:
+ http://oss.sgi.com/projects/kernprof/faq.html#Q9
+
+ Basically, if you get oopses in __free_pages_ok during boot when
+ you have this turned on, you need to fix gcc. The Redhat 2.96
+ version and gcc-3.x seem to work.
+
+ If not debugging a stack overflow problem, say N
+
config X86_EXTRA_IRQS
bool
depends on X86_LOCAL_APIC
diff -Nru a/arch/i386/Makefile b/arch/i386/Makefile
--- a/arch/i386/Makefile Sun Dec 15 21:16:27 2002
+++ b/arch/i386/Makefile Sun Dec 15 21:16:27 2002
@@ -52,6 +52,10 @@
MACHINE := mach-generic
endif
+ifdef CONFIG_X86_STACK_CHECK
+CFLAGS += -p
+endif
+
HEAD := arch/i386/kernel/head.o arch/i386/kernel/init_task.o
libs-y += arch/i386/lib/
diff -Nru a/arch/i386/boot/compressed/misc.c b/arch/i386/boot/compressed/misc.c
--- a/arch/i386/boot/compressed/misc.c Sun Dec 15 21:16:27 2002
+++ b/arch/i386/boot/compressed/misc.c Sun Dec 15 21:16:27 2002
@@ -377,3 +377,7 @@
if (high_loaded) close_output_buffer_if_we_run_high(mv);
return high_loaded;
}
+
+/* We don't actually check for stack overflows this early. */
+__asm__(".globl mcount ; mcount: ret\n");
+
diff -Nru a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
--- a/arch/i386/kernel/entry.S Sun Dec 15 21:16:27 2002
+++ b/arch/i386/kernel/entry.S Sun Dec 15 21:16:27 2002
@@ -520,6 +520,61 @@
pushl $do_spurious_interrupt_bug
jmp error_code
+
+#ifdef CONFIG_X86_STACK_CHECK
+.data
+ .globl stack_overflowed
+stack_overflowed:
+ .long 0
+.text
+
+ENTRY(mcount)
+ push %eax
+ movl $(THREAD_SIZE - 1),%eax
+ andl %esp,%eax
+ cmpl $STACK_WARN,%eax /* more than half the stack is used*/
+ jle 1f
+2:
+ popl %eax
+ ret
+1:
+ lock; btsl $0,stack_overflowed
+ jc 2b
+
+ # switch to overflow stack
+ movl %esp,%eax
+ movl $(stack_overflow_stack + THREAD_SIZE - 4),%esp
+
+ pushf
+ cli
+ pushl %eax
+
+ # push eip then esp of error for stack_overflow_panic
+ pushl 4(%eax)
+ pushl %eax
+
+ # update the task pointer and cpu in the overflow stack's thread_info.
+ GET_THREAD_INFO_WITH_ESP(%eax)
+ movl TI_TASK(%eax),%ebx
+ movl %ebx,stack_overflow_stack+TI_TASK
+ movl TI_CPU(%eax),%ebx
+ movl %ebx,stack_overflow_stack+TI_CPU
+
+ call stack_overflow
+
+ # pop off call arguments
+ addl $8,%esp
+
+ popl %eax
+ popf
+ movl %eax,%esp
+ popl %eax
+ movl $0,stack_overflowed
+ ret
+
+#warning stack check enabled
+#endif
+
.data
ENTRY(sys_call_table)
.long sys_restart_syscall /* 0 - old "setup()" system call, used for restarting */
diff -Nru a/arch/i386/kernel/i386_ksyms.c b/arch/i386/kernel/i386_ksyms.c
--- a/arch/i386/kernel/i386_ksyms.c Sun Dec 15 21:16:27 2002
+++ b/arch/i386/kernel/i386_ksyms.c Sun Dec 15 21:16:27 2002
@@ -216,3 +216,8 @@
EXPORT_SYMBOL(edd);
EXPORT_SYMBOL(eddnr);
#endif
+
+#ifdef CONFIG_X86_STACK_CHECK
+extern void mcount(void);
+EXPORT_SYMBOL(mcount);
+#endif
diff -Nru a/arch/i386/kernel/init_task.c b/arch/i386/kernel/init_task.c
--- a/arch/i386/kernel/init_task.c Sun Dec 15 21:16:27 2002
+++ b/arch/i386/kernel/init_task.c Sun Dec 15 21:16:27 2002
@@ -16,6 +16,10 @@
union thread_union init_irq_union
__attribute__((__section__(".data.init_task")));
+#ifdef CONFIG_X86_STACK_CHECK
+union thread_union stack_overflow_stack
+ __attribute__((__section__(".data.init_task")));
+#endif
/*
* Initial thread structure.
diff -Nru a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
--- a/arch/i386/kernel/process.c Sun Dec 15 21:16:27 2002
+++ b/arch/i386/kernel/process.c Sun Dec 15 21:16:27 2002
@@ -158,7 +158,25 @@
__setup("idle=", idle_setup);
-void show_regs(struct pt_regs * regs)
+void stack_overflow(unsigned long esp, unsigned long eip)
+{
+ int panicing = ((esp&(THREAD_SIZE-1)) <= STACK_PANIC);
+
+ printk( "esp: 0x%x masked: 0x%x STACK_PANIC:0x%x %d %d\n",
+ esp, (esp&(THREAD_SIZE-1)), STACK_PANIC, (((esp&(THREAD_SIZE-1)) <= STACK_PANIC)), panicing );
+
+ if (panicing)
+ print_symbol("stack overflow from %s\n", eip);
+ else
+ print_symbol("excessive stack use from %s\n", eip);
+ printk("esp: %p\n", (void*)esp);
+ show_trace((void*)esp);
+
+ if (panicing)
+ panic("stack overflow\n");
+}
+
+asmlinkage void show_regs(struct pt_regs * regs)
{
unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
diff -Nru a/include/asm-i386/thread_info.h b/include/asm-i386/thread_info.h
--- a/include/asm-i386/thread_info.h Sun Dec 15 21:16:27 2002
+++ b/include/asm-i386/thread_info.h Sun Dec 15 21:16:27 2002
@@ -63,6 +63,8 @@
*/
#define THREAD_ORDER 1
#define INIT_THREAD_SIZE THREAD_SIZE
+#define STACK_PANIC 0x200ul
+#define STACK_WARN ((THREAD_SIZE)>>1)
#ifndef __ASSEMBLY__
^ permalink raw reply [flat|nested] 2+ messages in thread
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2002-12-09 22:09 [PATCH] (3/4) stack updates for x86 Dave Hansen
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