[PATCH] Remove hardcoded offsets from i386 asm

From: Brian Gerst
Date: Thu May 13 2004 - 21:38:14 EST

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Generate offsets for thread_info, cpuinfo_x86, and a few others instead of hardcoding them.

--
Brian Gerst
diff -urN linux-2.6.6-bk/arch/i386/kernel/asm-offsets.c linux/arch/i386/kernel/asm-offsets.c
--- linux-2.6.6-bk/arch/i386/kernel/asm-offsets.c 2004-05-11 10:26:40.000000000 -0400
+++ linux/arch/i386/kernel/asm-offsets.c 2004-05-13 10:19:07.000000000 -0400
@@ -6,30 +6,60 @@

#include <linux/sched.h>
#include <linux/signal.h>
+#include <linux/personality.h>
#include <asm/ucontext.h>
#include "sigframe.h"
#include <asm/fixmap.h>
+#include <asm/processor.h>
+#include <asm/thread_info.h>

#define DEFINE(sym, val) \
asm volatile("\n->" #sym " %0 " #val : : "i" (val))

#define BLANK() asm volatile("\n->" : : )

+#define OFFSET(sym, str, mem) \
+ DEFINE(sym, offsetof(struct str, mem));
+
void foo(void)
{
- DEFINE(SIGCONTEXT_eax, offsetof (struct sigcontext, eax));
- DEFINE(SIGCONTEXT_ebx, offsetof (struct sigcontext, ebx));
- DEFINE(SIGCONTEXT_ecx, offsetof (struct sigcontext, ecx));
- DEFINE(SIGCONTEXT_edx, offsetof (struct sigcontext, edx));
- DEFINE(SIGCONTEXT_esi, offsetof (struct sigcontext, esi));
- DEFINE(SIGCONTEXT_edi, offsetof (struct sigcontext, edi));
- DEFINE(SIGCONTEXT_ebp, offsetof (struct sigcontext, ebp));
- DEFINE(SIGCONTEXT_esp, offsetof (struct sigcontext, esp));
- DEFINE(SIGCONTEXT_eip, offsetof (struct sigcontext, eip));
+ OFFSET(SIGCONTEXT_eax, sigcontext, eax);
+ OFFSET(SIGCONTEXT_ebx, sigcontext, ebx);
+ OFFSET(SIGCONTEXT_ecx, sigcontext, ecx);
+ OFFSET(SIGCONTEXT_edx, sigcontext, edx);
+ OFFSET(SIGCONTEXT_esi, sigcontext, esi);
+ OFFSET(SIGCONTEXT_edi, sigcontext, edi);
+ OFFSET(SIGCONTEXT_ebp, sigcontext, ebp);
+ OFFSET(SIGCONTEXT_esp, sigcontext, esp);
+ OFFSET(SIGCONTEXT_eip, sigcontext, eip);
+ BLANK();
+
+ OFFSET(CPUINFO_x86, cpuinfo_x86, x86);
+ OFFSET(CPUINFO_x86_vendor, cpuinfo_x86, x86_vendor);
+ OFFSET(CPUINFO_x86_model, cpuinfo_x86, x86_model);
+ OFFSET(CPUINFO_x86_mask, cpuinfo_x86, x86_mask);
+ OFFSET(CPUINFO_hard_math, cpuinfo_x86, hard_math);
+ OFFSET(CPUINFO_cpuid_level, cpuinfo_x86, cpuid_level);
+ OFFSET(CPUINFO_x86_capability, cpuinfo_x86, x86_capability);
+ OFFSET(CPUINFO_x86_vendor_id, cpuinfo_x86, x86_vendor_id);
BLANK();

- DEFINE(RT_SIGFRAME_sigcontext,
- offsetof (struct rt_sigframe, uc.uc_mcontext));
+ OFFSET(TI_task, thread_info, task);
+ OFFSET(TI_exec_domain, thread_info, exec_domain);
+ OFFSET(TI_flags, thread_info, flags);
+ OFFSET(TI_status, thread_info, status);
+ OFFSET(TI_cpu, thread_info, cpu);
+ OFFSET(TI_preempt_count, thread_info, preempt_count);
+ OFFSET(TI_addr_limit, thread_info, addr_limit);
+ OFFSET(TI_restart_block, thread_info, restart_block);
+ BLANK();
+
+ OFFSET(EXEC_DOMAIN_handler, exec_domain, handler);
+ OFFSET(RT_SIGFRAME_sigcontext, rt_sigframe, uc.uc_mcontext);
+
+ /* Offset from the sysenter stack to tss.esp0 */
+ DEFINE(TSS_sysenter_esp0, offsetof(struct tss_struct, esp0) -
+ sizeof(struct tss_struct));

DEFINE(PAGE_SIZE_asm, PAGE_SIZE);
}
diff -urN linux-2.6.6-bk/arch/i386/kernel/entry.S linux/arch/i386/kernel/entry.S
--- linux-2.6.6-bk/arch/i386/kernel/entry.S 2004-05-11 10:26:48.000000000 -0400
+++ linux/arch/i386/kernel/entry.S 2004-05-13 11:38:55.000000000 -0400
@@ -74,12 +74,6 @@
NT_MASK = 0x00004000
VM_MASK = 0x00020000

-/*
- * ESP0 is at offset 4. 0x200 is the size of the TSS, and
- * also thus the top-of-stack pointer offset of SYSENTER_ESP
- */
-TSS_ESP0_OFFSET = (4 - 0x200)
-
#ifdef CONFIG_PREEMPT
#define preempt_stop cli
#else
@@ -163,8 +157,8 @@
movl %edx,EIP(%ebp) # Now we move them to their "normal" places
movl %ecx,CS(%ebp) #
GET_THREAD_INFO_WITH_ESP(%ebp) # GET_THREAD_INFO
- movl TI_EXEC_DOMAIN(%ebp), %edx # Get the execution domain
- call *4(%edx) # Call the lcall7 handler for the domain
+ movl TI_exec_domain(%ebp), %edx # Get the execution domain
+ call *EXEC_DOMAIN_handler(%edx) # Call the handler for the domain
addl $4, %esp
popl %eax
jmp resume_userspace
@@ -208,7 +202,7 @@
cli # make sure we don't miss an interrupt
# setting need_resched or sigpending
# between sampling and the iret
- movl TI_FLAGS(%ebp), %ecx
+ movl TI_flags(%ebp), %ecx
andl $_TIF_WORK_MASK, %ecx # is there any work to be done on
# int/exception return?
jne work_pending
@@ -216,18 +210,18 @@

#ifdef CONFIG_PREEMPT
ENTRY(resume_kernel)
- cmpl $0,TI_PRE_COUNT(%ebp) # non-zero preempt_count ?
+ cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ?
jnz restore_all
need_resched:
- movl TI_FLAGS(%ebp), %ecx # need_resched set ?
+ movl TI_flags(%ebp), %ecx # need_resched set ?
testb $_TIF_NEED_RESCHED, %cl
jz restore_all
testl $IF_MASK,EFLAGS(%esp) # interrupts off (exception path) ?
jz restore_all
- movl $PREEMPT_ACTIVE,TI_PRE_COUNT(%ebp)
+ movl $PREEMPT_ACTIVE,TI_preempt_count(%ebp)
sti
call schedule
- movl $0,TI_PRE_COUNT(%ebp)
+ movl $0,TI_preempt_count(%ebp)
cli
jmp need_resched
#endif
@@ -237,7 +231,7 @@

# sysenter call handler stub
ENTRY(sysenter_entry)
- movl TSS_ESP0_OFFSET(%esp),%esp
+ movl TSS_sysenter_esp0(%esp),%esp
sysenter_past_esp:
sti
pushl $(__USER_DS)
@@ -264,12 +258,12 @@
cmpl $(nr_syscalls), %eax
jae syscall_badsys

- testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),TI_FLAGS(%ebp)
+ testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
jnz syscall_trace_entry
call *sys_call_table(,%eax,4)
movl %eax,EAX(%esp)
cli
- movl TI_FLAGS(%ebp), %ecx
+ movl TI_flags(%ebp), %ecx
testw $_TIF_ALLWORK_MASK, %cx
jne syscall_exit_work
/* if something modifies registers it must also disable sysexit */
@@ -287,7 +281,7 @@
cmpl $(nr_syscalls), %eax
jae syscall_badsys
# system call tracing in operation
- testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),TI_FLAGS(%ebp)
+ testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
jnz syscall_trace_entry
syscall_call:
call *sys_call_table(,%eax,4)
@@ -296,7 +290,7 @@
cli # make sure we don't miss an interrupt
# setting need_resched or sigpending
# between sampling and the iret
- movl TI_FLAGS(%ebp), %ecx
+ movl TI_flags(%ebp), %ecx
testw $_TIF_ALLWORK_MASK, %cx # current->work
jne syscall_exit_work
restore_all:
@@ -312,7 +306,7 @@
cli # make sure we don't miss an interrupt
# setting need_resched or sigpending
# between sampling and the iret
- movl TI_FLAGS(%ebp), %ecx
+ movl TI_flags(%ebp), %ecx
andl $_TIF_WORK_MASK, %ecx # is there any work to be done other
# than syscall tracing?
jz restore_all
@@ -473,7 +467,7 @@
* that sets up the real kernel stack. Check here, since we can't
* allow the wrong stack to be used.
*
- * "TSS_ESP0_OFFSET+12" is because the NMI/debug handler will have
+ * "TSS_sysenter_esp0+12" is because the NMI/debug handler will have
* already pushed 3 words if it hits on the sysenter instruction:
* eflags, cs and eip.
*
@@ -485,7 +479,7 @@
cmpw $__KERNEL_CS,4(%esp); \
jne ok; \
label: \
- movl TSS_ESP0_OFFSET+offset(%esp),%esp; \
+ movl TSS_sysenter_esp0+offset(%esp),%esp; \
pushfl; \
pushl $__KERNEL_CS; \
pushl $sysenter_past_esp
diff -urN linux-2.6.6-bk/arch/i386/kernel/head.S linux/arch/i386/kernel/head.S
--- linux-2.6.6-bk/arch/i386/kernel/head.S 2004-05-11 10:26:48.000000000 -0400
+++ linux/arch/i386/kernel/head.S 2004-05-13 09:59:26.000000000 -0400
@@ -24,15 +24,14 @@
* References to members of the new_cpu_data structure.
*/

-#define CPU_PARAMS new_cpu_data
-#define X86 CPU_PARAMS+0
-#define X86_VENDOR CPU_PARAMS+1
-#define X86_MODEL CPU_PARAMS+2
-#define X86_MASK CPU_PARAMS+3
-#define X86_HARD_MATH CPU_PARAMS+6
-#define X86_CPUID CPU_PARAMS+8
-#define X86_CAPABILITY CPU_PARAMS+12
-#define X86_VENDOR_ID CPU_PARAMS+36 /* offset dependent on NCAPINTS */
+#define X86 new_cpu_data+CPUINFO_x86
+#define X86_VENDOR new_cpu_data+CPUINFO_x86_vendor
+#define X86_MODEL new_cpu_data+CPUINFO_x86_model
+#define X86_MASK new_cpu_data+CPUINFO_x86_mask
+#define X86_HARD_MATH new_cpu_data+CPUINFO_hard_math
+#define X86_CPUID new_cpu_data+CPUINFO_cpuid_level
+#define X86_CAPABILITY new_cpu_data+CPUINFO_x86_capability
+#define X86_VENDOR_ID new_cpu_data+CPUINFO_x86_vendor_id

/*
* This is how much memory *in addition to the memory covered up to
diff -urN linux-2.6.6-bk/arch/i386/lib/getuser.S linux/arch/i386/lib/getuser.S
--- linux-2.6.6-bk/arch/i386/lib/getuser.S 2003-12-17 21:57:59.000000000 -0500
+++ linux/arch/i386/lib/getuser.S 2004-05-13 09:59:26.000000000 -0400
@@ -28,7 +28,7 @@
.globl __get_user_1
__get_user_1:
GET_THREAD_INFO(%edx)
- cmpl TI_ADDR_LIMIT(%edx),%eax
+ cmpl TI_addr_limit(%edx),%eax
jae bad_get_user
1: movzbl (%eax),%edx
xorl %eax,%eax
@@ -40,7 +40,7 @@
addl $1,%eax
jc bad_get_user
GET_THREAD_INFO(%edx)
- cmpl TI_ADDR_LIMIT(%edx),%eax
+ cmpl TI_addr_limit(%edx),%eax
jae bad_get_user
2: movzwl -1(%eax),%edx
xorl %eax,%eax
@@ -52,7 +52,7 @@
addl $3,%eax
jc bad_get_user
GET_THREAD_INFO(%edx)
- cmpl TI_ADDR_LIMIT(%edx),%eax
+ cmpl TI_addr_limit(%edx),%eax
jae bad_get_user
3: movl -3(%eax),%edx
xorl %eax,%eax
diff -urN linux-2.6.6-bk/include/asm-i386/thread_info.h linux/include/asm-i386/thread_info.h
--- linux-2.6.6-bk/include/asm-i386/thread_info.h 2004-05-11 10:26:57.000000000 -0400
+++ linux/include/asm-i386/thread_info.h 2004-05-13 09:59:26.000000000 -0400
@@ -47,15 +47,7 @@

#else /* !__ASSEMBLY__ */

-/* offsets into the thread_info struct for assembly code access */
-#define TI_TASK 0x00000000
-#define TI_EXEC_DOMAIN 0x00000004
-#define TI_FLAGS 0x00000008
-#define TI_STATUS 0x0000000C
-#define TI_CPU 0x00000010
-#define TI_PRE_COUNT 0x00000014
-#define TI_ADDR_LIMIT 0x00000018
-#define TI_RESTART_BLOCK 0x000001C
+#include <asm/asm_offsets.h>

#endif

Next message: Andrew Morton: "Re: [PATCH] allow console drivers to be called early"
Previous message: Andrew Morton: "Re: [PATCH][RFC] truncate vs add_to_page_cache race"
Next in thread: Vincent Hanquez: "Re: [PATCH] Remove hardcoded offsets from i386 asm"
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