[PATCH] s390: kernel stack options.
From: Martin Schwidefsky
Date: Mon Aug 30 2004 - 13:28:05 EST
[PATCH] s390: kernel stack options.
From: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
This adds support for the new compiler options -mkernel-backchain,
-mstack-size, -mstack-guard, -mwarn-dynamicstack and -mwarn-framesize.
The option -mkernel-backchain enables the use of modified layout for
the stack frames of kernel functions. This breaks the ABI, modules
compiled with the option won't work on a kernel compiled with the
option and vice versa. The positive effect of the option is a drastic
reduction of kernel stack use. The trick is that the new frame layout
allows to overlap the 96 (31 bit)/160 (64 bit) byte bias areas of the
functions on the call chain. This lowers the minimal stack usage of a
function from 96 bytes to 16 bytes (31 bit) and 160 bytes to 24 bytes
(64 bit). The kernel stack use is decreased to a point where it is
possible to use 4K (31 bit) / 8K (64 bit) stacks. The split into
process stack and interrupt stack is already in place.
The options -mstack-size and -mstack-guard are used to detect kernel
stack overflows. The compiler adds code to the prolog of every function
that causes an illegal operation if the kernel stack is about to overflow.
The options -mwarn-dynamicstack and -mwarn-framesize cause the compiler
to emit warnings if a function uses dynamic stack allocation or if the
function frame size is bigger then a specified limit.
To play safe all the new options are configuratable.
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
diffstat:
arch/s390/Kconfig | 126 ++++++++++++++++++++++++++++++++---------
arch/s390/Makefile | 26 +++++++-
arch/s390/defconfig | 14 +++-
arch/s390/kernel/asm-offsets.c | 4 +
arch/s390/kernel/entry.S | 85 +++++++++++++++++++--------
arch/s390/kernel/entry64.S | 91 ++++++++++++++++++++---------
arch/s390/kernel/head.S | 6 +
arch/s390/kernel/head64.S | 6 +
arch/s390/kernel/process.c | 68 ++++++++--------------
arch/s390/kernel/setup.c | 4 +
arch/s390/kernel/smp.c | 14 +++-
arch/s390/kernel/traps.c | 96 ++++++++++++++++++++++---------
include/asm-s390/lowcore.h | 8 +-
include/asm-s390/processor.h | 19 ++++++
include/asm-s390/thread_info.h | 38 +++++++-----
15 files changed, 428 insertions(+), 177 deletions(-)
diff -urN linux-2.6/arch/s390/Kconfig linux-2.6-s390/arch/s390/Kconfig
--- linux-2.6/arch/s390/Kconfig Mon Aug 30 19:14:07 2004
+++ linux-2.6-s390/arch/s390/Kconfig Mon Aug 30 19:14:22 2004
@@ -48,33 +48,6 @@
depends on ARCH_S390X = 'n'
default y
-choice
- prompt "Processor type"
- default MARCH_G5
-
-config MARCH_G5
- bool "S/390 model G5 and G6"
- depends on ARCH_S390_31
- help
- Select this to build a 31 bit kernel that works
- on all S/390 and zSeries machines.
-
-config MARCH_Z900
- bool "IBM eServer zSeries model z800 and z900"
- help
- Select this to optimize for zSeries machines. This
- will enable some optimizations that are not available
- on older 31 bit only CPUs.
-
-config MARCH_Z990
- bool "IBM eServer zSeries model z890 and z990"
- help
- Select this enable optimizations for model z890/z990.
- This will be slightly faster but does not work on
- older machines such as the z900.
-
-endchoice
-
config SMP
bool "Symmetric multi-processing support"
---help---
@@ -149,6 +122,105 @@
This allows you to run 32-bit Linux/ELF binaries on your zSeries
in 64 bit mode. Everybody wants this; say Y.
+comment "Code generation options"
+
+choice
+ prompt "Processor type"
+ default MARCH_G5
+
+config MARCH_G5
+ bool "S/390 model G5 and G6"
+ depends on ARCH_S390_31
+ help
+ Select this to build a 31 bit kernel that works
+ on all S/390 and zSeries machines.
+
+config MARCH_Z900
+ bool "IBM eServer zSeries model z800 and z900"
+ help
+ Select this to optimize for zSeries machines. This
+ will enable some optimizations that are not available
+ on older 31 bit only CPUs.
+
+config MARCH_Z990
+ bool "IBM eServer zSeries model z890 and z990"
+ help
+ Select this enable optimizations for model z890/z990.
+ This will be slightly faster but does not work on
+ older machines such as the z900.
+
+endchoice
+
+config PACK_STACK
+ bool "Pack kernel stack"
+ help
+ This option enables the compiler option -mkernel-backchain if it
+ is available. If the option is available the compiler supports
+ the new stack layout which dramatically reduces the minimum stack
+ frame size. With an old compiler a non-leaf function needs a
+ minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
+ -mkernel-backchain the minimum size drops to 16 byte on 31 bit
+ and 24 byte on 64 bit.
+
+ Say Y if you are unsure.
+
+config SMALL_STACK
+ bool "Use 4kb/8kb for kernel stack instead of 8kb/16kb"
+ depends on PACK_STACK
+ help
+ If you say Y here and the compiler supports the -mkernel-backchain
+ option the kernel will use a smaller kernel stack size. For 31 bit
+ the reduced size is 4kb instead of 8kb and for 64 bit it is 8kb
+ instead of 16kb. This allows to run more thread on a system and
+ reduces the pressure on the memory management for higher order
+ page allocations.
+
+ Say N if you are unsure.
+
+
+config CHECK_STACK
+ bool "Detect kernel stack overflow"
+ help
+ This option enables the compiler option -mstack-guard and
+ -mstack-size if they are available. If the compiler supports them
+ it will emit additional code to each function prolog to trigger
+ an illegal operation if the kernel stack is about to overflow.
+
+ Say N if you are unsure.
+
+config STACK_GUARD
+ int "Size of the guard area (128-1024)"
+ range 128 1024
+ depends on CHECK_STACK
+ default "256"
+ help
+ This allows you to specify the size of the guard area at the lower
+ end of the kernel stack. If the kernel stack points into the guard
+ area on function entry an illegal operation is triggered. The size
+ needs to be a power of 2. Please keep in mind that the size of an
+ interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
+ The minimum size for the stack guard should be 256 for 31 bit and
+ 512 for 64 bit.
+
+config WARN_STACK
+ bool "Emit compiler warnings for function with broken stack usage"
+ help
+ This option enables the compiler options -mwarn-framesize and
+ -mwarn-dynamicstack. If the compiler supports these options it
+ will generate warnings for function which either use alloca or
+ create a stack frame bigger then CONFIG_WARN_STACK_SIZE.
+
+ Say N if you are unsure.
+
+config WARN_STACK_SIZE
+ int "Maximum frame size considered safe (128-2048)"
+ range 128 2048
+ depends on WARN_STACK
+ default "256"
+ help
+ This allows you to specify the maximum frame size a function may
+ have without the compiler complaining about it.
+
comment "I/O subsystem configuration"
config MACHCHK_WARNING
diff -urN linux-2.6/arch/s390/Makefile linux-2.6-s390/arch/s390/Makefile
--- linux-2.6/arch/s390/Makefile Mon Aug 30 19:14:07 2004
+++ linux-2.6-s390/arch/s390/Makefile Mon Aug 30 19:14:22 2004
@@ -18,6 +18,7 @@
CFLAGS += -m31
AFLAGS += -m31
UTS_MACHINE := s390
+STACK_SIZE := 8192
endif
ifdef CONFIG_ARCH_S390X
@@ -26,16 +27,37 @@
CFLAGS += -m64
AFLAGS += -m64
UTS_MACHINE := s390x
+STACK_SIZE := 16384
endif
cflags-$(CONFIG_MARCH_G5) += $(call cc-option,-march=g5)
cflags-$(CONFIG_MARCH_Z900) += $(call cc-option,-march=z900)
cflags-$(CONFIG_MARCH_Z990) += $(call cc-option,-march=z990)
-CFLAGS += $(cflags-y)
+ifeq ($(call cc-option-yn,-mkernel-backchain),y)
+cflags-$(CONFIG_PACK_STACK) += -mkernel-backchain -D__PACK_STACK
+aflags-$(CONFIG_PACK_STACK) += -D__PACK_STACK
+cflags-$(CONFIG_SMALL_STACK) += -D__SMALL_STACK
+aflags-$(CONFIG_SMALL_STACK) += -D__SMALL_STACK
+ifdef CONFIG_SMALL_STACK
+STACK_SIZE := $(shell echo $$(($(STACK_SIZE)/2)) )
+endif
+endif
+
+ifeq ($(call cc-option-yn,-mstack-size=8192 -mstack-guard=128),y)
+cflags-$(CONFIG_CHECK_STACK) += -mstack-size=$(STACK_SIZE)
+cflags-$(CONFIG_CHECK_STACK) += -mstack-guard=$(CONFIG_STACK_GUARD)
+endif
+
+ifeq ($(call cc-option-yn,-mwarn-dynamicstack),y)
+cflags-$(CONFIG_WARN_STACK) += -mwarn-dynamicstack
+cflags-$(CONFIG_WARN_STACK) += -mwarn-framesize=$(CONFIG_WARN_STACK_SIZE)
+endif
+
+CFLAGS += -mbackchain $(cflags-y)
CFLAGS += $(call cc-option,-finline-limit=10000)
CFLAGS += -pipe -fno-strength-reduce -Wno-sign-compare
-CFLAGS += -mbackchain
+AFLAGS += $(aflags-y)
OBJCOPYFLAGS := -O binary
LDFLAGS_vmlinux := -e start
diff -urN linux-2.6/arch/s390/defconfig linux-2.6-s390/arch/s390/defconfig
--- linux-2.6/arch/s390/defconfig Mon Aug 30 19:14:22 2004
+++ linux-2.6-s390/arch/s390/defconfig Mon Aug 30 19:14:22 2004
@@ -58,15 +58,23 @@
# CONFIG_ARCH_S390X is not set
# CONFIG_64BIT is not set
CONFIG_ARCH_S390_31=y
-CONFIG_MARCH_G5=y
-# CONFIG_MARCH_Z900 is not set
-# CONFIG_MARCH_Z990 is not set
CONFIG_SMP=y
CONFIG_NR_CPUS=32
# CONFIG_HOTPLUG_CPU is not set
CONFIG_MATHEMU=y
#
+# Code generation options
+#
+CONFIG_MARCH_G5=y
+# CONFIG_MARCH_Z900 is not set
+# CONFIG_MARCH_Z990 is not set
+CONFIG_PACK_STACK=y
+# CONFIG_SMALL_STACK is not set
+# CONFIG_CHECK_STACK is not set
+# CONFIG_WARN_STACK is not set
+
+#
# I/O subsystem configuration
#
CONFIG_MACHCHK_WARNING=y
diff -urN linux-2.6/arch/s390/kernel/asm-offsets.c linux-2.6-s390/arch/s390/kernel/asm-offsets.c
--- linux-2.6/arch/s390/kernel/asm-offsets.c Sat Aug 14 12:55:09 2004
+++ linux-2.6-s390/arch/s390/kernel/asm-offsets.c Mon Aug 30 19:14:22 2004
@@ -39,5 +39,9 @@
DEFINE(__PT_ILC, offsetof(struct pt_regs, ilc),);
DEFINE(__PT_TRAP, offsetof(struct pt_regs, trap),);
DEFINE(__PT_SIZE, sizeof(struct pt_regs),);
+ BLANK();
+ DEFINE(__SF_BACKCHAIN, offsetof(struct stack_frame, back_chain),);
+ DEFINE(__SF_GPRS, offsetof(struct stack_frame, gprs),);
+ DEFINE(__SF_EMPTY, offsetof(struct stack_frame, empty1),);
return 0;
}
diff -urN linux-2.6/arch/s390/kernel/entry.S linux-2.6-s390/arch/s390/kernel/entry.S
--- linux-2.6/arch/s390/kernel/entry.S Mon Aug 30 19:14:22 2004
+++ linux-2.6-s390/arch/s390/kernel/entry.S Mon Aug 30 19:14:22 2004
@@ -19,6 +19,7 @@
#include <asm/thread_info.h>
#include <asm/offsets.h>
#include <asm/unistd.h>
+#include <asm/page.h>
/*
* Stack layout for the system_call stack entry.
@@ -52,6 +53,9 @@
_TIF_RESTART_SVC | _TIF_SINGLE_STEP )
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED)
+STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
+STACK_SIZE = 1 << STACK_SHIFT
+
#define BASED(name) name-system_call(%r13)
/*
@@ -86,10 +90,16 @@
bnz BASED(1f)
0: l %r14,__LC_ASYNC_STACK # are we already on the async stack ?
slr %r14,%r15
- sra %r14,13
+ sra %r14,STACK_SHIFT
be BASED(2f)
1: l %r15,__LC_ASYNC_STACK
.endif
+#ifdef CONFIG_CHECK_STACK
+ b BASED(3f)
+2: tml %r15,STACK_SIZE - CONFIG_STACK_GUARD
+ bz BASED(stack_overflow)
+3:
+#endif
2: s %r15,BASED(.Lc_spsize) # make room for registers & psw
mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack
la %r12,\psworg
@@ -99,7 +109,7 @@
st %r12,SP_ILC(%r15)
mvc SP_R12(16,%r15),\savearea # move %r12-%r15 to stack
la %r12,0
- st %r12,0(%r15) # clear back chain
+ st %r12,__SF_BACKCHAIN(%r15) # clear back chain
.endm
.macro RESTORE_ALL sync
@@ -124,19 +134,19 @@
__switch_to_base:
tm __THREAD_per(%r3),0xe8 # new process is using per ?
bz __switch_to_noper-__switch_to_base(%r1) # if not we're fine
- stctl %c9,%c11,24(%r15) # We are using per stuff
- clc __THREAD_per(12,%r3),24(%r15)
+ stctl %c9,%c11,__SF_EMPTY(%r15) # We are using per stuff
+ clc __THREAD_per(12,%r3),__SF_EMPTY(%r15)
be __switch_to_noper-__switch_to_base(%r1) # we got away w/o bashing TLB's
lctl %c9,%c11,__THREAD_per(%r3) # Nope we didn't
__switch_to_noper:
- stm %r6,%r15,24(%r15) # store __switch_to registers of prev task
+ stm %r6,%r15,__SF_GPRS(%r15)# store __switch_to registers of prev task
st %r15,__THREAD_ksp(%r2) # store kernel stack to prev->tss.ksp
l %r15,__THREAD_ksp(%r3) # load kernel stack from next->tss.ksp
- lm %r6,%r15,24(%r15) # load __switch_to registers of next task
+ lm %r6,%r15,__SF_GPRS(%r15)# load __switch_to registers of next task
st %r3,__LC_CURRENT # __LC_CURRENT = current task struct
l %r3,__THREAD_info(%r3) # load thread_info from task struct
st %r3,__LC_THREAD_INFO
- ahi %r3,8192
+ ahi %r3,STACK_SIZE
st %r3,__LC_KERNEL_STACK # __LC_KERNEL_STACK = new kernel stack
br %r14
@@ -146,24 +156,24 @@
*/
.global do_call_softirq
do_call_softirq:
- stnsm 24(%r15),0xfc
- stm %r12,%r15,28(%r15)
+ stnsm __SF_EMPTY(%r15),0xfc
+ stm %r12,%r15,__SF_GPRS(%r15)
lr %r12,%r15
basr %r13,0
do_call_base:
l %r0,__LC_ASYNC_STACK
slr %r0,%r15
- sra %r0,13
+ sra %r0,STACK_SHIFT
be 0f-do_call_base(%r13)
l %r15,__LC_ASYNC_STACK
0: sl %r15,.Lc_overhead-do_call_base(%r13)
- st %r12,0(%r15) # store backchain
+ st %r12,__SF_BACKCHAIN(%r15) # store backchain
l %r1,.Ldo_softirq-do_call_base(%r13)
basr %r14,%r1
- lm %r12,%r15,28(%r12)
- ssm 24(%r15)
+ lm %r12,%r15,__SF_GPRS(%r12)
+ ssm __SF_EMPTY(%r15)
br %r14
-
+
__critical_start:
/*
* SVC interrupt handler routine. System calls are synchronous events and
@@ -309,7 +319,7 @@
st %r15,SP_R15(%r15) # store stack pointer for new kthread
0: l %r1,BASED(.Lschedtail)
basr %r14,%r1
- stosm 24(%r15),0x03 # reenable interrupts
+ stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
b BASED(sysc_return)
#
@@ -460,7 +470,7 @@
mvc __THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS
mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
oi __TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
- stosm 24(%r15),0x03 # reenable interrupts
+ stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
b BASED(sysc_do_svc)
/*
@@ -496,16 +506,16 @@
l %r1,SP_R15(%r15)
s %r1,BASED(.Lc_spsize)
mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
- xc 0(4,%r1),0(%r1) # clear back chain
+ xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain
lr %r15,%r1
io_resume_loop:
tm __TI_flags+3(%r9),_TIF_NEED_RESCHED
bno BASED(io_leave)
mvc __TI_precount(4,%r9),BASED(.Lc_pactive)
- stosm 24(%r15),0x03 # reenable interrupts
+ stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
l %r1,BASED(.Lschedule)
basr %r14,%r1 # call schedule
- stnsm 24(%r15),0xfc # disable I/O and ext. interrupts
+ stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
xc __TI_precount(4,%r9),__TI_precount(%r9)
b BASED(io_resume_loop)
#endif
@@ -517,7 +527,7 @@
l %r1,__LC_KERNEL_STACK
s %r1,BASED(.Lc_spsize)
mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
- xc 0(4,%r1),0(%r1) # clear back chain
+ xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain
lr %r15,%r1
#
# One of the work bits is on. Find out which one.
@@ -535,9 +545,9 @@
#
io_reschedule:
l %r1,BASED(.Lschedule)
- stosm 24(%r15),0x03 # reenable interrupts
+ stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
basr %r14,%r1 # call scheduler
- stnsm 24(%r15),0xfc # disable I/O and ext. interrupts
+ stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
tm __TI_flags+3(%r9),_TIF_WORK_INT
bz BASED(io_leave) # there is no work to do
b BASED(io_work_loop)
@@ -546,12 +556,12 @@
# _TIF_SIGPENDING is set, call do_signal
#
io_sigpending:
- stosm 24(%r15),0x03 # reenable interrupts
+ stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
la %r2,SP_PTREGS(%r15) # load pt_regs
sr %r3,%r3 # clear *oldset
l %r1,BASED(.Ldo_signal)
basr %r14,%r1 # call do_signal
- stnsm 24(%r15),0xfc # disable I/O and ext. interrupts
+ stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
b BASED(io_leave) # out of here, do NOT recheck
/*
@@ -593,7 +603,7 @@
lctl %c0,%c15,__LC_CREGS_SAVE_AREA # get new ctl regs
lam %a0,%a15,__LC_AREGS_SAVE_AREA
stosm 0(%r15),0x04 # now we can turn dat on
- lm %r6,%r15,24(%r15) # load registers from clone
+ lm %r6,%r15,__SF_GPRS(%r15) # load registers from clone
basr %r14,0
l %r14,restart_addr-.(%r14)
br %r14 # branch to start_secondary
@@ -614,6 +624,31 @@
restart_go:
#endif
+#ifdef CONFIG_CHECK_STACK
+/*
+ * The synchronous or the asynchronous stack overflowed. We are dead.
+ * No need to properly save the registers, we are going to panic anyway.
+ * Setup a pt_regs so that show_trace can provide a good call trace.
+ */
+stack_overflow:
+ l %r15,__LC_PANIC_STACK # change to panic stack
+ sl %r15,BASED(.Lc_spsize)
+ mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack
+ stm %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack
+ la %r1,__LC_SAVE_AREA
+ ch %r12,BASED(.L0x020) # old psw addr == __LC_SVC_OLD_PSW ?
+ be BASED(0f)
+ ch %r12,BASED(.L0x028) # old psw addr == __LC_PGM_OLD_PSW ?
+ be BASED(0f)
+ la %r1,__LC_SAVE_AREA+16
+0: mvc SP_R12(16,%r15),0(%r1) # move %r12-%r15 to stack
+ xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear back chain
+ l %r1,BASED(1f) # branch to kernel_stack_overflow
+ la %r2,SP_PTREGS(%r15) # load pt_regs
+ br %r1
+1: .long kernel_stack_overflow
+#endif
+
cleanup_table_system_call:
.long system_call + 0x80000000, sysc_do_svc + 0x80000000
cleanup_table_sysc_return:
diff -urN linux-2.6/arch/s390/kernel/entry64.S linux-2.6-s390/arch/s390/kernel/entry64.S
--- linux-2.6/arch/s390/kernel/entry64.S Mon Aug 30 19:14:22 2004
+++ linux-2.6-s390/arch/s390/kernel/entry64.S Mon Aug 30 19:14:22 2004
@@ -19,6 +19,7 @@
#include <asm/thread_info.h>
#include <asm/offsets.h>
#include <asm/unistd.h>
+#include <asm/page.h>
/*
* Stack layout for the system_call stack entry.
@@ -48,6 +49,9 @@
SP_TRAP = STACK_FRAME_OVERHEAD + __PT_TRAP
SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE
+STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
+STACK_SIZE = 1 << STACK_SHIFT
+
_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
_TIF_RESTART_SVC | _TIF_SINGLE_STEP )
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED)
@@ -85,10 +89,16 @@
jnz 1f
0: lg %r14,__LC_ASYNC_STACK # are we already on the async. stack ?
slgr %r14,%r15
- srag %r14,%r14,14
+ srag %r14,%r14,STACK_SHIFT
jz 2f
1: lg %r15,__LC_ASYNC_STACK # load async stack
.endif
+#ifdef CONFIG_CHECK_STACK
+ j 3f
+2: tml %r15,STACK_SIZE - CONFIG_STACK_GUARD
+ jz stack_overflow
+3:
+#endif
2: aghi %r15,-SP_SIZE # make room for registers & psw
mvc SP_PSW(16,%r15),0(%r12) # move user PSW to stack
la %r12,\psworg
@@ -98,7 +108,7 @@
st %r12,SP_ILC(%r15)
mvc SP_R12(32,%r15),\savearea # move %r12-%r15 to stack
la %r12,0
- stg %r12,0(%r15)
+ stg %r12,__SF_BACKCHAIN(%r15)
.endm
.macro RESTORE_ALL sync
@@ -121,19 +131,19 @@
__switch_to:
tm __THREAD_per+4(%r3),0xe8 # is the new process using per ?
jz __switch_to_noper # if not we're fine
- stctg %c9,%c11,48(%r15) # We are using per stuff
- clc __THREAD_per(24,%r3),48(%r15)
+ stctg %c9,%c11,__SF_EMPTY(%r15)# We are using per stuff
+ clc __THREAD_per(24,%r3),__SF_EMPTY(%r15)
je __switch_to_noper # we got away without bashing TLB's
lctlg %c9,%c11,__THREAD_per(%r3) # Nope we didn't
__switch_to_noper:
- stmg %r6,%r15,48(%r15) # store __switch_to registers of prev task
+ stmg %r6,%r15,__SF_GPRS(%r15)# store __switch_to registers of prev task
stg %r15,__THREAD_ksp(%r2) # store kernel stack to prev->tss.ksp
lg %r15,__THREAD_ksp(%r3) # load kernel stack from next->tss.ksp
- lmg %r6,%r15,48(%r15) # load __switch_to registers of next task
+ lmg %r6,%r15,__SF_GPRS(%r15)# load __switch_to registers of next task
stg %r3,__LC_CURRENT # __LC_CURRENT = current task struct
lg %r3,__THREAD_info(%r3) # load thread_info from task struct
stg %r3,__LC_THREAD_INFO
- aghi %r3,16384
+ aghi %r3,STACK_SIZE
stg %r3,__LC_KERNEL_STACK # __LC_KERNEL_STACK = new kernel stack
br %r14
@@ -143,19 +153,19 @@
*/
.global do_call_softirq
do_call_softirq:
- stnsm 48(%r15),0xfc
- stmg %r12,%r15,56(%r15)
+ stnsm __SF_EMPTY(%r15),0xfc
+ stmg %r12,%r15,__SF_GPRS(%r15)
lgr %r12,%r15
lg %r0,__LC_ASYNC_STACK
slgr %r0,%r15
- srag %r0,%r0,14
+ srag %r0,%r0,STACK_SHIFT
je 0f
lg %r15,__LC_ASYNC_STACK
0: aghi %r15,-STACK_FRAME_OVERHEAD
- stg %r12,0(%r15) # store back chain
+ stg %r12,__SF_BACKCHAIN(%r15) # store back chain
brasl %r14,do_softirq
- lmg %r12,%r15,56(%r12)
- ssm 48(%r15)
+ lmg %r12,%r15,__SF_GPRS(%r12)
+ ssm __SF_EMPTY(%r15)
br %r14
__critical_start:
@@ -507,7 +517,7 @@
mvc __THREAD_per+__PER_address(8,%r1),__LC_PER_ADDRESS
mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
oi __TI_flags+7(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
- stosm 48(%r15),0x03 # reenable interrupts
+ stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
j sysc_do_svc
/*
@@ -542,16 +552,16 @@
lg %r1,SP_R15(%r15)
aghi %r1,-SP_SIZE
mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
- xc 0(8,%r1),0(%r1) # clear back chain
+ xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) # clear back chain
lgr %r15,%r1
io_resume_loop:
tm __TI_flags+7(%r9),_TIF_NEED_RESCHED
jno io_leave
larl %r1,.Lc_pactive
mvc __TI_precount(4,%r9),0(%r1)
- stosm 48(%r15),0x03 # reenable interrupts
+ stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
brasl %r14,schedule # call schedule
- stnsm 48(%r15),0xfc # disable I/O and ext. interrupts
+ stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
xc __TI_precount(4,%r9),__TI_precount(%r9)
j io_resume_loop
#endif
@@ -563,7 +573,7 @@
lg %r1,__LC_KERNEL_STACK
aghi %r1,-SP_SIZE
mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
- xc 0(8,%r1),0(%r1) # clear back chain
+ xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) # clear back chain
lgr %r15,%r1
#
# One of the work bits is on. Find out which one.
@@ -580,23 +590,23 @@
# _TIF_NEED_RESCHED is set, call schedule
#
io_reschedule:
- stosm 48(%r15),0x03 # reenable interrupts
- brasl %r14,schedule # call scheduler
- stnsm 48(%r15),0xfc # disable I/O and ext. interrupts
+ stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
+ brasl %r14,schedule # call scheduler
+ stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
tm __TI_flags+7(%r9),_TIF_WORK_INT
- jz io_leave # there is no work to do
+ jz io_leave # there is no work to do
j io_work_loop
#
# _TIF_SIGPENDING is set, call do_signal
#
io_sigpending:
- stosm 48(%r15),0x03 # reenable interrupts
- la %r2,SP_PTREGS(%r15) # load pt_regs
- slgr %r3,%r3 # clear *oldset
- brasl %r14,do_signal # call do_signal
- stnsm 48(%r15),0xfc # disable I/O and ext. interrupts
- j sysc_leave # out of here, do NOT recheck
+ stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
+ la %r2,SP_PTREGS(%r15) # load pt_regs
+ slgr %r3,%r3 # clear *oldset
+ brasl %r14,do_signal # call do_signal
+ stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
+ j sysc_leave # out of here, do NOT recheck
/*
* External interrupt handler routine
@@ -635,7 +645,7 @@
lghi %r10,__LC_AREGS_SAVE_AREA
lam %a0,%a15,0(%r10)
stosm 0(%r15),0x04 # now we can turn dat on
- lmg %r6,%r15,48(%r15) # load registers from clone
+ lmg %r6,%r15,__SF_GPRS(%r15) # load registers from clone
jg start_secondary
#else
/*
@@ -652,6 +662,29 @@
restart_go:
#endif
+#ifdef CONFIG_CHECK_STACK
+/*
+ * The synchronous or the asynchronous stack overflowed. We are dead.
+ * No need to properly save the registers, we are going to panic anyway.
+ * Setup a pt_regs so that show_trace can provide a good call trace.
+ */
+stack_overflow:
+ lg %r15,__LC_PANIC_STACK # change to panic stack
+ aghi %r1,-SP_SIZE
+ mvc SP_PSW(16,%r15),0(%r12) # move user PSW to stack
+ stmg %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack
+ la %r1,__LC_SAVE_AREA
+ chi %r12,__LC_SVC_OLD_PSW
+ je 0f
+ chi %r12,__LC_PGM_OLD_PSW
+ je 0f
+ la %r1,__LC_SAVE_AREA+16
+0: mvc SP_R12(32,%r15),0(%r1) # move %r12-%r15 to stack
+ xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) # clear back chain
+ la %r2,SP_PTREGS(%r15) # load pt_regs
+ jg kernel_stack_overflow
+#endif
+
cleanup_table_system_call:
.quad system_call, sysc_do_svc
cleanup_table_sysc_return:
diff -urN linux-2.6/arch/s390/kernel/head.S linux-2.6-s390/arch/s390/kernel/head.S
--- linux-2.6/arch/s390/kernel/head.S Sat Aug 14 12:55:09 2004
+++ linux-2.6-s390/arch/s390/kernel/head.S Mon Aug 30 19:14:22 2004
@@ -31,6 +31,8 @@
#include <asm/setup.h>
#include <asm/lowcore.h>
#include <asm/offsets.h>
+#include <asm/thread_info.h>
+#include <asm/page.h>
#ifndef CONFIG_IPL
.org 0
@@ -741,10 +743,10 @@
#
l %r15,.Linittu-.LPG2(%r13)
mvc __LC_CURRENT(4),__TI_task(%r15)
- ahi %r15,8192 # init_task_union + 8192
+ ahi %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
st %r15,__LC_KERNEL_STACK # set end of kernel stack
ahi %r15,-96
- xc 0(4,%r15),0(%r15) # set backchain to zero
+ xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
# check control registers
stctl %c0,%c15,0(%r15)
diff -urN linux-2.6/arch/s390/kernel/head64.S linux-2.6-s390/arch/s390/kernel/head64.S
--- linux-2.6/arch/s390/kernel/head64.S Sat Aug 14 12:55:10 2004
+++ linux-2.6-s390/arch/s390/kernel/head64.S Mon Aug 30 19:14:22 2004
@@ -31,6 +31,8 @@
#include <asm/setup.h>
#include <asm/lowcore.h>
#include <asm/offsets.h>
+#include <asm/thread_info.h>
+#include <asm/page.h>
#ifndef CONFIG_IPL
.org 0
@@ -741,10 +743,10 @@
larl %r15,init_thread_union
lg %r14,__TI_task(%r15) # cache current in lowcore
stg %r14,__LC_CURRENT
- aghi %r15,16384 # init_task_union + 16384
+ aghi %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
stg %r15,__LC_KERNEL_STACK # set end of kernel stack
aghi %r15,-160
- xc 0(8,%r15),0(%r15) # set backchain to zero
+ xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
# check control registers
stctg %c0,%c15,0(%r15)
diff -urN linux-2.6/arch/s390/kernel/process.c linux-2.6-s390/arch/s390/kernel/process.c
--- linux-2.6/arch/s390/kernel/process.c Mon Aug 30 19:14:22 2004
+++ linux-2.6-s390/arch/s390/kernel/process.c Mon Aug 30 19:14:22 2004
@@ -58,14 +58,11 @@
*/
unsigned long thread_saved_pc(struct task_struct *tsk)
{
- unsigned long bc;
+ struct stack_frame *sf;
- bc = *((unsigned long *) tsk->thread.ksp);
-#ifndef CONFIG_ARCH_S390X
- return *((unsigned long *) (bc+56));
-#else
- return *((unsigned long *) (bc+112));
-#endif
+ sf = (struct stack_frame *) tsk->thread.ksp;
+ sf = (struct stack_frame *) sf->back_chain;
+ return sf->gprs[8];
}
/*
@@ -232,20 +229,13 @@
unsigned long unused,
struct task_struct * p, struct pt_regs * regs)
{
- struct stack_frame
+ struct fake_frame
{
- unsigned long back_chain;
- unsigned long eos;
- unsigned long glue1;
- unsigned long glue2;
- unsigned long scratch[2];
- unsigned long gprs[10]; /* gprs 6 -15 */
- unsigned int fprs[4]; /* fpr 4 and 6 */
- unsigned int empty[4];
+ struct stack_frame sf;
struct pt_regs childregs;
} *frame;
- frame = ((struct stack_frame *)
+ frame = ((struct fake_frame *)
(THREAD_SIZE + (unsigned long) p->thread_info)) - 1;
p->thread.ksp = (unsigned long) frame;
p->set_child_tid = p->clear_child_tid = NULL;
@@ -253,13 +243,13 @@
frame->childregs = *regs;
frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */
frame->childregs.gprs[15] = new_stackp;
- frame->back_chain = frame->eos = 0;
+ frame->sf.back_chain = 0;
/* new return point is ret_from_fork */
- frame->gprs[8] = (unsigned long) ret_from_fork;
+ frame->sf.gprs[8] = (unsigned long) ret_from_fork;
/* fake return stack for resume(), don't go back to schedule */
- frame->gprs[9] = (unsigned long) frame;
+ frame->sf.gprs[9] = (unsigned long) frame;
/* Save access registers to new thread structure. */
save_access_regs(&p->thread.acrs[0]);
@@ -402,30 +392,26 @@
unsigned long get_wchan(struct task_struct *p)
{
- unsigned long r14, r15, bc;
- unsigned long stack_page;
- int count = 0;
- if (!p || p == current || p->state == TASK_RUNNING)
+ struct stack_frame *sf, *low, *high;
+ unsigned long return_address;
+ int count;
+
+ if (!p || p == current || p->state == TASK_RUNNING || !p->thread_info)
return 0;
- stack_page = (unsigned long) p->thread_info;
- r15 = p->thread.ksp;
- if (!stack_page || r15 < stack_page ||
- r15 >= THREAD_SIZE - sizeof(unsigned long) + stack_page)
+ low = (struct stack_frame *) p->thread_info;
+ high = (struct stack_frame *)
+ ((unsigned long) p->thread_info + THREAD_SIZE) - 1;
+ sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN);
+ if (sf <= low || sf > high)
return 0;
- bc = (*(unsigned long *) r15) & PSW_ADDR_INSN;
- do {
- if (bc < stack_page ||
- bc >= THREAD_SIZE - sizeof(unsigned long) + stack_page)
+ for (count = 0; count < 16; count++) {
+ sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
+ if (sf <= low || sf > high)
return 0;
-#ifndef CONFIG_ARCH_S390X
- r14 = (*(unsigned long *) (bc+56)) & PSW_ADDR_INSN;
-#else
- r14 = *(unsigned long *) (bc+112);
-#endif
- if (!in_sched_functions(r14))
- return r14;
- bc = (*(unsigned long *) bc) & PSW_ADDR_INSN;
- } while (count++ < 16);
+ return_address = sf->gprs[8] & PSW_ADDR_INSN;
+ if (!in_sched_functions(return_address))
+ return return_address;
+ }
return 0;
}
diff -urN linux-2.6/arch/s390/kernel/setup.c linux-2.6-s390/arch/s390/kernel/setup.c
--- linux-2.6/arch/s390/kernel/setup.c Sat Aug 14 12:54:48 2004
+++ linux-2.6-s390/arch/s390/kernel/setup.c Mon Aug 30 19:14:22 2004
@@ -503,6 +503,10 @@
lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
lc->async_stack = (unsigned long)
__alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
+#ifdef CONFIG_CHECK_STACK
+ lc->panic_stack = (unsigned long)
+ __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
+#endif
lc->current_task = (unsigned long) init_thread_union.thread_info.task;
lc->thread_info = (unsigned long) &init_thread_union;
#ifdef CONFIG_ARCH_S390X
diff -urN linux-2.6/arch/s390/kernel/smp.c linux-2.6-s390/arch/s390/kernel/smp.c
--- linux-2.6/arch/s390/kernel/smp.c Mon Aug 30 19:14:07 2004
+++ linux-2.6-s390/arch/s390/kernel/smp.c Mon Aug 30 19:14:22 2004
@@ -741,7 +741,7 @@
void __init smp_prepare_cpus(unsigned int max_cpus)
{
- unsigned long async_stack;
+ unsigned long stack;
unsigned int cpu;
int i;
@@ -761,12 +761,18 @@
lowcore_ptr[i] = (struct _lowcore *)
__get_free_pages(GFP_KERNEL|GFP_DMA,
sizeof(void*) == 8 ? 1 : 0);
- async_stack = __get_free_pages(GFP_KERNEL,ASYNC_ORDER);
- if (lowcore_ptr[i] == NULL || async_stack == 0ULL)
+ stack = __get_free_pages(GFP_KERNEL,ASYNC_ORDER);
+ if (lowcore_ptr[i] == NULL || stack == 0ULL)
panic("smp_boot_cpus failed to allocate memory\n");
*(lowcore_ptr[i]) = S390_lowcore;
- lowcore_ptr[i]->async_stack = async_stack + (ASYNC_SIZE);
+ lowcore_ptr[i]->async_stack = stack + (ASYNC_SIZE);
+#ifdef CONFIG_CHECK_STACK
+ stack = __get_free_pages(GFP_KERNEL,0);
+ if (stack == 0ULL)
+ panic("smp_boot_cpus failed to allocate memory\n");
+ lowcore_ptr[i]->panic_stack = stack + (PAGE_SIZE);
+#endif
}
set_prefix((u32)(unsigned long) lowcore_ptr[smp_processor_id()]);
diff -urN linux-2.6/arch/s390/kernel/traps.c linux-2.6-s390/arch/s390/kernel/traps.c
--- linux-2.6/arch/s390/kernel/traps.c Sat Aug 14 12:55:10 2004
+++ linux-2.6-s390/arch/s390/kernel/traps.c Mon Aug 30 19:14:22 2004
@@ -67,54 +67,93 @@
#define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
#ifndef CONFIG_ARCH_S390X
-#define RET_ADDR 56
#define FOURLONG "%08lx %08lx %08lx %08lx\n"
static int kstack_depth_to_print = 12;
-
#else /* CONFIG_ARCH_S390X */
-#define RET_ADDR 112
#define FOURLONG "%016lx %016lx %016lx %016lx\n"
static int kstack_depth_to_print = 20;
-
#endif /* CONFIG_ARCH_S390X */
-void show_trace(struct task_struct *task, unsigned long * stack)
+/*
+ * For show_trace we have tree different stack to consider:
+ * - the panic stack which is used if the kernel stack has overflown
+ * - the asynchronous interrupt stack (cpu related)
+ * - the synchronous kernel stack (process related)
+ * The stack trace can start at any of the three stack and can potentially
+ * touch all of them. The order is: panic stack, async stack, sync stack.
+ */
+static unsigned long
+__show_trace(unsigned long sp, unsigned long low, unsigned long high)
{
- unsigned long backchain, low_addr, high_addr, ret_addr;
+ struct stack_frame *sf;
+ struct pt_regs *regs;
- if (!stack)
- stack = (task == NULL) ? *stack_pointer : &(task->thread.ksp);
+ while (1) {
+ sp = sp & PSW_ADDR_INSN;
+ if (sp < low || sp > high - sizeof(*sf))
+ return sp;
+ sf = (struct stack_frame *) sp;
+ printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
+ print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
+ /* Follow the backchain. */
+ while (1) {
+ low = sp;
+ sp = sf->back_chain & PSW_ADDR_INSN;
+ if (!sp)
+ break;
+ if (sp <= low || sp > high - sizeof(*sf))
+ return sp;
+ sf = (struct stack_frame *) sp;
+ printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
+ print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
+ }
+ /* Zero backchain detected, check for interrupt frame. */
+ sp = (unsigned long) (sf + 1);
+ if (sp <= low || sp > high - sizeof(*regs))
+ return sp;
+ regs = (struct pt_regs *) sp;
+ printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
+ print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
+ low = sp;
+ sp = regs->gprs[15];
+ }
+}
+void show_trace(struct task_struct *task, unsigned long * stack)
+{
+ register unsigned long __r15 asm ("15");
+ unsigned long sp;
+
+ sp = (unsigned long) stack;
+ if (!sp)
+ sp = task ? task->thread.ksp : __r15;
printk("Call Trace:\n");
- low_addr = ((unsigned long) stack) & PSW_ADDR_INSN;
- high_addr = (low_addr & (-THREAD_SIZE)) + THREAD_SIZE;
- /* Skip the first frame (biased stack) */
- backchain = *((unsigned long *) low_addr) & PSW_ADDR_INSN;
- /* Print up to 8 lines */
- while (backchain > low_addr && backchain <= high_addr) {
- ret_addr = *((unsigned long *) (backchain+RET_ADDR)) & PSW_ADDR_INSN;
- printk(" [<%016lx>] ", ret_addr);
- print_symbol("%s\n", ret_addr);
- low_addr = backchain;
- backchain = *((unsigned long *) backchain) & PSW_ADDR_INSN;
- }
+#ifdef CONFIG_CHECK_STACK
+ sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
+ S390_lowcore.panic_stack);
+#endif
+ sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
+ S390_lowcore.async_stack);
+ if (task)
+ __show_trace(sp, (unsigned long) task->thread_info,
+ (unsigned long) task->thread_info + THREAD_SIZE);
+ else
+ __show_trace(sp, S390_lowcore.thread_info - THREAD_SIZE,
+ S390_lowcore.thread_info);
printk("\n");
}
void show_stack(struct task_struct *task, unsigned long *sp)
{
+ register unsigned long * __r15 asm ("15");
unsigned long *stack;
int i;
// debugging aid: "show_stack(NULL);" prints the
// back trace for this cpu.
- if (!sp) {
- if (task)
- sp = (unsigned long *) task->thread.ksp;
- else
- sp = *stack_pointer;
- }
+ if (!sp)
+ sp = task ? (unsigned long *) task->thread.ksp : __r15;
stack = sp;
for (i = 0; i < kstack_depth_to_print; i++) {
@@ -591,6 +630,11 @@
}
}
+asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
+{
+ die("Kernel stack overflow", regs, 0);
+ panic("Corrupt kernel stack, can't continue.");
+}
/* init is done in lowcore.S and head.S */
diff -urN linux-2.6/include/asm-s390/lowcore.h linux-2.6-s390/include/asm-s390/lowcore.h
--- linux-2.6/include/asm-s390/lowcore.h Sat Aug 14 12:55:32 2004
+++ linux-2.6-s390/include/asm-s390/lowcore.h Mon Aug 30 19:14:22 2004
@@ -68,6 +68,7 @@
#define __LC_ASYNC_STACK 0xC48
#define __LC_KERNEL_ASCE 0xC4C
#define __LC_USER_ASCE 0xC50
+#define __LC_PANIC_STACK 0xC54
#define __LC_CPUID 0xC60
#define __LC_CPUADDR 0xC68
#define __LC_IPLDEV 0xC7C
@@ -80,6 +81,7 @@
#define __LC_ASYNC_STACK 0xD50
#define __LC_KERNEL_ASCE 0xD58
#define __LC_USER_ASCE 0xD60
+#define __LC_PANIC_STACK 0xD68
#define __LC_CPUID 0xD90
#define __LC_CPUADDR 0xD98
#define __LC_IPLDEV 0xDB8
@@ -176,7 +178,8 @@
__u32 async_stack; /* 0xc48 */
__u32 kernel_asce; /* 0xc4c */
__u32 user_asce; /* 0xc50 */
- __u8 pad10[0xc60-0xc54]; /* 0xc54 */
+ __u32 panic_stack; /* 0xc54 */
+ __u8 pad10[0xc60-0xc58]; /* 0xc58 */
/* entry.S sensitive area start */
struct cpuinfo_S390 cpu_data; /* 0xc60 */
__u32 ipl_device; /* 0xc7c */
@@ -257,7 +260,8 @@
__u64 async_stack; /* 0xd50 */
__u64 kernel_asce; /* 0xd58 */
__u64 user_asce; /* 0xd60 */
- __u8 pad10[0xd80-0xd68]; /* 0xd68 */
+ __u64 panic_stack; /* 0xd68 */
+ __u8 pad10[0xd80-0xd70]; /* 0xd70 */
/* entry.S sensitive area start */
struct cpuinfo_S390 cpu_data; /* 0xd80 */
__u32 ipl_device; /* 0xdb8 */
diff -urN linux-2.6/include/asm-s390/processor.h linux-2.6-s390/include/asm-s390/processor.h
--- linux-2.6/include/asm-s390/processor.h Mon Aug 30 19:14:12 2004
+++ linux-2.6-s390/include/asm-s390/processor.h Mon Aug 30 19:14:22 2004
@@ -103,6 +103,25 @@
typedef struct thread_struct thread_struct;
+/*
+ * Stack layout of a C stack frame.
+ */
+#ifndef __PACK_STACK
+struct stack_frame {
+ unsigned long back_chain;
+ unsigned long empty1[5];
+ unsigned long gprs[10];
+ unsigned int empty2[8];
+};
+#else
+struct stack_frame {
+ unsigned long empty1[5];
+ unsigned int empty2[8];
+ unsigned long gprs[10];
+ unsigned long back_chain;
+};
+#endif
+
#define ARCH_MIN_TASKALIGN 8
#ifndef __s390x__
diff -urN linux-2.6/include/asm-s390/thread_info.h linux-2.6-s390/include/asm-s390/thread_info.h
--- linux-2.6/include/asm-s390/thread_info.h Sat Aug 14 12:55:47 2004
+++ linux-2.6-s390/include/asm-s390/thread_info.h Mon Aug 30 19:14:22 2004
@@ -11,6 +11,30 @@
#ifdef __KERNEL__
+/*
+ * Size of kernel stack for each process
+ */
+#ifndef __s390x__
+#ifndef __SMALL_STACK
+#define THREAD_ORDER 1
+#define ASYNC_ORDER 1
+#else
+#define THREAD_ORDER 0
+#define ASYNC_ORDER 0
+#endif
+#else /* __s390x__ */
+#ifndef __SMALL_STACK_STACK
+#define THREAD_ORDER 2
+#define ASYNC_ORDER 2
+#else
+#define THREAD_ORDER 1
+#define ASYNC_ORDER 1
+#endif
+#endif /* __s390x__ */
+
+#define THREAD_SIZE (PAGE_SIZE << THREAD_ORDER)
+#define ASYNC_SIZE (PAGE_SIZE << ASYNC_ORDER)
+
#ifndef __ASSEMBLY__
#include <asm/processor.h>
#include <asm/lowcore.h>
@@ -47,20 +71,6 @@
#define init_thread_info (init_thread_union.thread_info)
#define init_stack (init_thread_union.stack)
-/*
- * Size of kernel stack for each process
- */
-#ifndef __s390x__
-#define THREAD_ORDER 1
-#define ASYNC_ORDER 1
-#else /* __s390x__ */
-#define THREAD_ORDER 2
-#define ASYNC_ORDER 2
-#endif /* __s390x__ */
-
-#define THREAD_SIZE (PAGE_SIZE << THREAD_ORDER)
-#define ASYNC_SIZE (PAGE_SIZE << ASYNC_ORDER)
-
/* how to get the thread information struct from C */
static inline struct thread_info *current_thread_info(void)
{
-
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