[PATCH] LTT for 2.5.38 4/9: i386 trace support

Karim Yaghmour (karim@opersys.com)
Sun, 22 Sep 2002 01:44:02 -0400


This patch adds i386 trace support.

Here are the file modifications:
arch/i386/config.in | 2
arch/i386/kernel/entry.S | 18 +++++++
arch/i386/kernel/irq.c | 6 ++
arch/i386/kernel/process.c | 6 ++
arch/i386/kernel/sys_i386.c | 4 +
arch/i386/kernel/traps.c | 105 +++++++++++++++++++++++++++++++++++++++++++-
arch/i386/mm/fault.c | 11 ++++
include/asm-i386/trace.h | 15 ++++++
8 files changed, 166 insertions, 1 deletion

diff -urpN linux-2.5.38/arch/i386/config.in linux-2.5.38-ltt/arch/i386/config.in
--- linux-2.5.38/arch/i386/config.in Sun Sep 22 00:25:05 2002
+++ linux-2.5.38-ltt/arch/i386/config.in Sun Sep 22 00:51:51 2002
@@ -421,6 +421,8 @@ source drivers/usb/Config.in

source net/bluetooth/Config.in

+source drivers/trace/Config.in
+
mainmenu_option next_comment
comment 'Kernel hacking'
if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
diff -urpN linux-2.5.38/arch/i386/kernel/entry.S linux-2.5.38-ltt/arch/i386/kernel/entry.S
--- linux-2.5.38/arch/i386/kernel/entry.S Sun Sep 22 00:25:04 2002
+++ linux-2.5.38-ltt/arch/i386/kernel/entry.S Sun Sep 22 00:51:51 2002
@@ -233,9 +233,27 @@ ENTRY(system_call)
testb $_TIF_SYSCALL_TRACE,TI_FLAGS(%ebx)
jnz syscall_trace_entry
syscall_call:
+#if (CONFIG_TRACE || CONFIG_TRACE_MODULE)
+ movl syscall_entry_trace_active, %eax
+ cmpl $1, %eax # are we tracing system call entries
+ jne no_syscall_entry_trace
+ movl %esp, %eax # copy the stack pointer
+ pushl %eax # pass the stack pointer copy
+ call trace_real_syscall_entry
+ addl $4,%esp # return stack to state before pass
+no_syscall_entry_trace:
+ movl ORIG_EAX(%esp),%eax # restore eax to it's original content
+#endif
call *sys_call_table(,%eax,4)
movl %eax,EAX(%esp) # store the return value
syscall_exit:
+#if (CONFIG_TRACE || CONFIG_TRACE_MODULE)
+ movl syscall_exit_trace_active, %eax
+ cmpl $1, %eax # are we tracing system call exits
+ jne no_syscall_exit_trace
+ call trace_real_syscall_exit
+no_syscall_exit_trace:
+#endif
cli # make sure we don't miss an interrupt
# setting need_resched or sigpending
# between sampling and the iret
diff -urpN linux-2.5.38/arch/i386/kernel/irq.c linux-2.5.38-ltt/arch/i386/kernel/irq.c
--- linux-2.5.38/arch/i386/kernel/irq.c Sun Sep 22 00:25:00 2002
+++ linux-2.5.38-ltt/arch/i386/kernel/irq.c Sun Sep 22 00:51:51 2002
@@ -33,6 +33,8 @@
#include <linux/proc_fs.h>
#include <linux/seq_file.h>

+#include <linux/trace.h>
+
#include <asm/atomic.h>
#include <asm/io.h>
#include <asm/smp.h>
@@ -202,6 +204,8 @@ int handle_IRQ_event(unsigned int irq, s
{
int status = 1; /* Force the "do bottom halves" bit */

+ TRACE_IRQ_ENTRY(irq, !(user_mode(regs)));
+
if (!(action->flags & SA_INTERRUPT))
local_irq_enable();

@@ -213,6 +217,8 @@ int handle_IRQ_event(unsigned int irq, s
if (status & SA_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
local_irq_disable();
+
+ TRACE_IRQ_EXIT();

return status;
}
diff -urpN linux-2.5.38/arch/i386/kernel/process.c linux-2.5.38-ltt/arch/i386/kernel/process.c
--- linux-2.5.38/arch/i386/kernel/process.c Sun Sep 22 00:24:57 2002
+++ linux-2.5.38-ltt/arch/i386/kernel/process.c Sun Sep 22 00:51:51 2002
@@ -34,6 +34,8 @@
#include <linux/init.h>
#include <linux/mc146818rtc.h>

+#include <linux/trace.h>
+
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
@@ -224,6 +226,10 @@ int kernel_thread(int (*fn)(void *), voi

/* Ok, create the new process.. */
p = do_fork(flags | CLONE_VM, 0, &regs, 0, NULL);
+#if (CONFIG_TRACE || CONFIG_TRACE_MODULE)
+ if(!IS_ERR(p))
+ TRACE_PROCESS(TRACE_EV_PROCESS_KTHREAD, p->pid, (int) fn);
+#endif
return IS_ERR(p) ? PTR_ERR(p) : p->pid;
}

diff -urpN linux-2.5.38/arch/i386/kernel/sys_i386.c linux-2.5.38-ltt/arch/i386/kernel/sys_i386.c
--- linux-2.5.38/arch/i386/kernel/sys_i386.c Sun Sep 22 00:25:09 2002
+++ linux-2.5.38-ltt/arch/i386/kernel/sys_i386.c Sun Sep 22 00:51:51 2002
@@ -19,6 +19,8 @@
#include <linux/file.h>
#include <linux/utsname.h>

+#include <linux/trace.h>
+
#include <asm/uaccess.h>
#include <asm/ipc.h>

@@ -136,6 +138,8 @@ asmlinkage int sys_ipc (uint call, int f

version = call >> 16; /* hack for backward compatibility */
call &= 0xffff;
+
+ TRACE_IPC(TRACE_EV_IPC_CALL, call, first);

switch (call) {
case SEMOP:
diff -urpN linux-2.5.38/arch/i386/kernel/traps.c linux-2.5.38-ltt/arch/i386/kernel/traps.c
--- linux-2.5.38/arch/i386/kernel/traps.c Sun Sep 22 00:25:02 2002
+++ linux-2.5.38-ltt/arch/i386/kernel/traps.c Sun Sep 22 00:51:51 2002
@@ -28,6 +28,8 @@
#include <linux/ioport.h>
#endif

+#include <linux/trace.h>
+
#ifdef CONFIG_MCA
#include <linux/mca.h>
#include <asm/processor.h>
@@ -278,6 +280,76 @@ bug:
printk("Kernel BUG\n");
}

+/* Trace related code */
+#if (CONFIG_TRACE || CONFIG_TRACE_MODULE)
+asmlinkage void trace_real_syscall_entry(struct pt_regs *regs)
+{
+ int use_depth;
+ int use_bounds;
+ int depth = 0;
+ int seek_depth;
+ unsigned long lower_bound;
+ unsigned long upper_bound;
+ unsigned long addr;
+ unsigned long *stack;
+ trace_syscall_entry trace_syscall_event;
+
+ /* Set the syscall ID */
+ trace_syscall_event.syscall_id = (uint8_t) regs->orig_eax;
+
+ /* Set the address in any case */
+ trace_syscall_event.address = regs->eip;
+
+ /* Are we in the kernel (This is a kernel thread)? */
+ if (!(regs->xcs & 3))
+ /* Don't go digining anywhere */
+ goto trace_syscall_end;
+
+ /* Get the trace configuration */
+ if (trace_get_config(&use_depth,
+ &use_bounds,
+ &seek_depth,
+ (void *) &lower_bound,
+ (void *) &upper_bound) < 0)
+ goto trace_syscall_end;
+
+ /* Do we have to search for an eip address range */
+ if ((use_depth == 1) || (use_bounds == 1)) {
+ /* Start at the top of the stack (bottom address since stacks grow downward) */
+ stack = (unsigned long *) regs->esp;
+
+ /* Keep on going until we reach the end of the process' stack limit (wherever it may be) */
+ while (!get_user(addr, stack)) {
+ /* Does this LOOK LIKE an address in the program */
+ if ((addr > current->mm->start_code)
+ && (addr < current->mm->end_code)) {
+ /* Does this address fit the description */
+ if (((use_depth == 1) && (depth == seek_depth))
+ || ((use_bounds == 1) && (addr > lower_bound) && (addr < upper_bound))) {
+ /* Set the address */
+ trace_syscall_event.address = addr;
+
+ /* We're done */
+ goto trace_syscall_end;
+ } else
+ /* We're one depth more */
+ depth++;
+ }
+ /* Go on to the next address */
+ stack++;
+ }
+ }
+trace_syscall_end:
+ /* Trace the event */
+ trace_event(TRACE_EV_SYSCALL_ENTRY, &trace_syscall_event);
+}
+
+asmlinkage void trace_real_syscall_exit(void)
+{
+ trace_event(TRACE_EV_SYSCALL_EXIT, NULL);
+}
+#endif /* (CONFIG_TRACE || CONFIG_TRACE_MODULE) */
+
spinlock_t die_lock = SPIN_LOCK_UNLOCKED;

void die(const char * str, struct pt_regs * regs, long err)
@@ -311,6 +383,8 @@ static inline unsigned long get_cr2(void
static void inline do_trap(int trapnr, int signr, char *str, int vm86,
struct pt_regs * regs, long error_code, siginfo_t *info)
{
+ TRACE_TRAP_ENTRY(trapnr, regs->eip);
+
if (vm86 && regs->eflags & VM_MASK)
goto vm86_trap;

@@ -325,6 +399,7 @@ static void inline do_trap(int trapnr, i
force_sig_info(signr, info, tsk);
else
force_sig(signr, tsk);
+ TRACE_TRAP_EXIT();
return;
}

@@ -350,14 +425,17 @@ static void inline do_trap(int trapnr, i
regs->eip = fixup;
else
die(str, regs, error_code);
+ TRACE_TRAP_EXIT();
return;
}

vm86_trap: {
int ret = handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, trapnr);
if (ret) goto trap_signal;
+ TRACE_TRAP_EXIT();
return;
}
+ TRACE_TRAP_EXIT();
}

#define DO_ERROR(trapnr, signr, str, name) \
@@ -417,11 +495,15 @@ asmlinkage void do_general_protection(st

current->thread.error_code = error_code;
current->thread.trap_no = 13;
+ TRACE_TRAP_ENTRY(13, regs->eip);
force_sig(SIGSEGV, current);
+ TRACE_TRAP_EXIT();
return;

gp_in_vm86:
+ TRACE_TRAP_ENTRY(13, regs->eip);
handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
+ TRACE_TRAP_EXIT();
return;

gp_in_kernel:
@@ -481,6 +563,12 @@ asmlinkage void do_nmi(struct pt_regs *
{
unsigned char reason = inb(0x61);

+#ifndef CONFIG_X86_LOCAL_APIC
+/* On an machines with APIC enabled, NMIs are used to implement a watchdog
+and will hang the machine if traced. */
+ TRACE_TRAP_ENTRY(2, regs->eip);
+#endif
+
++nmi_count(smp_processor_id());

if (!(reason & 0xc0)) {
@@ -491,10 +579,14 @@ asmlinkage void do_nmi(struct pt_regs *
*/
if (nmi_watchdog) {
nmi_watchdog_tick(regs);
+ TRACE_TRAP_EXIT();
return;
}
#endif
unknown_nmi_error(reason, regs);
+#ifndef CONFIG_X86_LOCAL_APIC
+ TRACE_TRAP_EXIT();
+#endif
return;
}
if (reason & 0x80)
@@ -509,6 +601,10 @@ asmlinkage void do_nmi(struct pt_regs *
inb(0x71); /* dummy */
outb(0x0f, 0x70);
inb(0x71); /* dummy */
+
+#ifndef CONFIG_X86_LOCAL_APIC
+ TRACE_TRAP_EXIT();
+#endif
}

/*
@@ -582,7 +678,9 @@ asmlinkage void do_debug(struct pt_regs
*/
info.si_addr = ((regs->xcs & 3) == 0) ? (void *)tsk->thread.eip :
(void *)regs->eip;
+ TRACE_TRAP_ENTRY(1, regs->eip);
force_sig_info(SIGTRAP, &info, tsk);
+ TRACE_TRAP_EXIT();

/* Disable additional traps. They'll be re-enabled when
* the signal is delivered.
@@ -594,7 +692,9 @@ clear_dr7:
return;

debug_vm86:
+ TRACE_TRAP_ENTRY(1, regs->eip);
handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1);
+ TRACE_TRAP_EXIT();
return;

clear_TF:
@@ -743,10 +843,12 @@ asmlinkage void do_simd_coprocessor_erro
asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs,
long error_code)
{
+ TRACE_TRAP_ENTRY(16, regs->eip);
#if 0
/* No need to warn about this any longer. */
printk("Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
#endif
+ TRACE_TRAP_EXIT();
}

/*
@@ -775,8 +877,10 @@ asmlinkage void math_emulate(long arg)
{
printk("math-emulation not enabled and no coprocessor found.\n");
printk("killing %s.\n",current->comm);
+ TRACE_TRAP_ENTRY(7, 0);
force_sig(SIGFPE,current);
schedule();
+ TRACE_TRAP_EXIT();
}

#endif /* CONFIG_MATH_EMULATION */
@@ -807,7 +911,6 @@ do { \
:"i" ((short) (0x8000+(dpl<<13)+(type<<8))), \
"3" ((char *) (addr)),"2" (__KERNEL_CS << 16)); \
} while (0)
-

/*
* This needs to use 'idt_table' rather than 'idt', and
diff -urpN linux-2.5.38/arch/i386/mm/fault.c linux-2.5.38-ltt/arch/i386/mm/fault.c
--- linux-2.5.38/arch/i386/mm/fault.c Sun Sep 22 00:24:57 2002
+++ linux-2.5.38-ltt/arch/i386/mm/fault.c Sun Sep 22 00:51:51 2002
@@ -20,6 +20,8 @@
#include <linux/tty.h>
#include <linux/vt_kern.h> /* For unblank_screen() */

+#include <linux/trace.h>
+
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
@@ -180,6 +182,8 @@ asmlinkage void do_page_fault(struct pt_
mm = tsk->mm;
info.si_code = SEGV_MAPERR;

+ TRACE_TRAP_ENTRY(14, regs->eip);
+
/*
* If we're in an interrupt, have no user context or are running in an
* atomic region then we must not take the fault..
@@ -264,6 +268,7 @@ good_area:
tsk->thread.screen_bitmap |= 1 << bit;
}
up_read(&mm->mmap_sem);
+ TRACE_TRAP_EXIT();
return;

/*
@@ -283,6 +288,7 @@ bad_area:
/* info.si_code has been set above */
info.si_addr = (void *)address;
force_sig_info(SIGSEGV, &info, tsk);
+ TRACE_TRAP_EXIT();
return;
}

@@ -297,6 +303,7 @@ bad_area:

if (nr == 6) {
do_invalid_op(regs, 0);
+ TRACE_TRAP_EXIT();
return;
}
}
@@ -306,6 +313,7 @@ no_context:
/* Are we prepared to handle this kernel fault? */
if ((fixup = search_exception_table(regs->eip)) != 0) {
regs->eip = fixup;
+ TRACE_TRAP_EXIT();
return;
}

@@ -379,6 +387,7 @@ do_sigbus:
/* Kernel mode? Handle exceptions or die */
if (!(error_code & 4))
goto no_context;
+ TRACE_TRAP_EXIT();
return;

vmalloc_fault:
@@ -412,6 +421,8 @@ vmalloc_fault:
pte_k = pte_offset_kernel(pmd_k, address);
if (!pte_present(*pte_k))
goto no_context;
+ TRACE_TRAP_EXIT();
return;
}
+ TRACE_TRAP_EXIT();
}
diff -urpN linux-2.5.38/include/asm-i386/trace.h linux-2.5.38-ltt/include/asm-i386/trace.h
--- linux-2.5.38/include/asm-i386/trace.h Wed Dec 31 19:00:00 1969
+++ linux-2.5.38-ltt/include/asm-i386/trace.h Sun Sep 22 00:51:51 2002
@@ -0,0 +1,15 @@
+/*
+ * linux/include/asm-i386/trace.h
+ *
+ * Copyright (C) 2002, Karim Yaghmour
+ *
+ * i386 definitions for tracing system
+ */
+
+#include <linux/trace.h>
+
+/* Current arch type */
+#define TRACE_ARCH_TYPE TRACE_ARCH_TYPE_I386
+
+/* Current variant type */
+#define TRACE_ARCH_VARIANT TRACE_ARCH_VARIANT_NONE
-
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