[PATCH] 5/8 LTT for 2.5.33: PowerPC trace support

Karim Yaghmour (karim@opersys.com)
Fri, 06 Sep 2002 18:16:38 -0400


This patch adds trace support for the PowerPC. Here are the files
modified:
arch/ppc/config.in
arch/ppc/kernel/entry.S
arch/ppc/kernel/irq.c
arch/ppc/kernel/misc.S
arch/ppc/kernel/process.c
arch/ppc/kernel/syscalls.c
arch/ppc/kernel/time.c
arch/ppc/kernel/traps.c
arch/ppc/mm/fault.c
include/asm-ppc/trace.h

At this time, this patch doesn't include the syscall entry/exit
tests provided in the i386 patch. This is on the to-do list and
should be relatively easy for someone familiar with PPC assembly.

--- linux-2.5.33/arch/ppc/config.in Sat Aug 31 18:04:45 2002
+++ linux-2.5.33-ltt/arch/ppc/config.in Fri Sep 6 12:03:20 2002
@@ -588,6 +588,8 @@

source lib/Config.in

+source drivers/trace/Config.in
+
mainmenu_option next_comment
comment 'Kernel hacking'

diff -urN linux-2.5.33/arch/ppc/kernel/entry.S linux-2.5.33-ltt/arch/ppc/kernel/entry.S
--- linux-2.5.33/arch/ppc/kernel/entry.S Sat Aug 31 18:05:34 2002
+++ linux-2.5.33-ltt/arch/ppc/kernel/entry.S Fri Sep 6 12:03:20 2002
@@ -106,6 +106,32 @@
RFI
#endif /* CONFIG_PPC_ISERIES */

+/* LTT stuff */
+#if (CONFIG_TRACE || CONFIG_TRACE_MODULE)
+#define TRACE_REAL_ASM_SYSCALL_ENTRY \
+ addi r3,r1,STACK_FRAME_OVERHEAD; /* Put pointer to registers into r3 */ \
+ mflr r29; /* Save LR */ \
+ bl trace_real_syscall_entry; /* Call real trace function */ \
+ mtlr r29; /* Restore LR */ \
+ lwz r0,GPR0(r1); /* Restore original registers */ \
+ lwz r3,GPR3(r1); \
+ lwz r4,GPR4(r1); \
+ lwz r5,GPR5(r1); \
+ lwz r6,GPR6(r1); \
+ lwz r7,GPR7(r1); \
+ lwz r8,GPR8(r1);
+#define TRACE_REAL_ASM_SYSCALL_EXIT \
+ bl trace_real_syscall_exit; /* Call real trace function */ \
+ lwz r0,GPR0(r1); /* Restore original registers */ \
+ lwz r3,RESULT(r1); \
+ lwz r4,GPR4(r1); \
+ lwz r5,GPR5(r1); \
+ lwz r6,GPR6(r1); \
+ lwz r7,GPR7(r1); \
+ lwz r8,GPR8(r1); \
+ addi r9,r1,STACK_FRAME_OVERHEAD;
+#endif
+
/*
* Handle a system call.
*/
@@ -136,12 +162,19 @@
slwi r0,r0,2
lwzx r10,r10,r0 /* Fetch system call handler [ptr] */
mtlr r10
+#if (CONFIG_TRACE || CONFIG_TRACE_MODULE)
+ TRACE_REAL_ASM_SYSCALL_ENTRY ;
+#endif
addi r9,r1,STACK_FRAME_OVERHEAD
blrl /* Call handler */
.globl ret_from_syscall
ret_from_syscall:
#ifdef SHOW_SYSCALLS
bl do_show_syscall_exit
+#endif
+#if (CONFIG_TRACE || CONFIG_TRACE_MODULE)
+ stw r3,RESULT(r1) /* Save result */
+ TRACE_REAL_ASM_SYSCALL_EXIT ;
#endif
mr r6,r3
li r11,-_LAST_ERRNO
diff -urN linux-2.5.33/arch/ppc/kernel/irq.c linux-2.5.33-ltt/arch/ppc/kernel/irq.c
--- linux-2.5.33/arch/ppc/kernel/irq.c Sat Aug 31 18:04:53 2002
+++ linux-2.5.33-ltt/arch/ppc/kernel/irq.c Fri Sep 6 12:03:20 2002
@@ -49,6 +49,8 @@
#include <linux/random.h>
#include <linux/seq_file.h>

+#include <linux/trace.h>
+
#include <asm/uaccess.h>
#include <asm/bitops.h>
#include <asm/system.h>
@@ -427,6 +429,8 @@
int cpu = smp_processor_id();
irq_desc_t *desc = irq_desc + irq;

+ TRACE_IRQ_ENTRY(irq, !(user_mode(regs)));
+
kstat.irqs[cpu][irq]++;
spin_lock(&desc->lock);
ack_irq(irq);
@@ -504,6 +508,8 @@
irq_desc[irq].handler->enable(irq);
}
spin_unlock(&desc->lock);
+
+ TRACE_IRQ_EXIT();
}

#ifndef CONFIG_PPC_ISERIES /* iSeries version is in iSeries_pic.c */
diff -urN linux-2.5.33/arch/ppc/kernel/misc.S linux-2.5.33-ltt/arch/ppc/kernel/misc.S
--- linux-2.5.33/arch/ppc/kernel/misc.S Sat Aug 31 18:04:56 2002
+++ linux-2.5.33-ltt/arch/ppc/kernel/misc.S Fri Sep 6 12:03:20 2002
@@ -1016,7 +1016,11 @@
* Create a kernel thread
* kernel_thread(fn, arg, flags)
*/
+#if (CONFIG_TRACE || CONFIG_TRACE_MODULE)
+_GLOBAL(original_kernel_thread)
+#else
_GLOBAL(kernel_thread)
+#endif /* (CONFIG_TRACE || CONFIG_TRACE_MODULE) */
stwu r1,-16(r1)
stw r30,8(r1)
stw r31,12(r1)
diff -urN linux-2.5.33/arch/ppc/kernel/process.c linux-2.5.33-ltt/arch/ppc/kernel/process.c
--- linux-2.5.33/arch/ppc/kernel/process.c Sat Aug 31 18:05:10 2002
+++ linux-2.5.33-ltt/arch/ppc/kernel/process.c Fri Sep 6 14:23:50 2002
@@ -37,6 +37,8 @@
#include <linux/prctl.h>
#include <linux/init_task.h>

+#include <linux/trace.h>
+
#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/system.h>
@@ -296,6 +298,19 @@
printk("\n");
show_stack((unsigned long *)regs->gpr[1]);
}
+
+#if (CONFIG_TRACE || CONFIG_TRACE_MODULE)
+long original_kernel_thread(int (*fn) (void *), void* arg, unsigned long flags);
+long kernel_thread(int (*fn) (void *), void* arg, unsigned long flags)
+{
+ long retval;
+
+ retval = original_kernel_thread(fn, arg, flags);
+ if (retval > 0)
+ TRACE_PROCESS(TRACE_EV_PROCESS_KTHREAD, retval, (int) fn);
+ return retval;
+}
+#endif /* (CONFIG_TRACE || CONFIG_TRACE_MODULE) */

void exit_thread(void)
{
diff -urN linux-2.5.33/arch/ppc/kernel/syscalls.c linux-2.5.33-ltt/arch/ppc/kernel/syscalls.c
--- linux-2.5.33/arch/ppc/kernel/syscalls.c Sat Aug 31 18:05:34 2002
+++ linux-2.5.33-ltt/arch/ppc/kernel/syscalls.c Fri Sep 6 12:03:20 2002
@@ -39,6 +39,8 @@
#include <linux/utsname.h>
#include <linux/file.h>

+#include <linux/trace.h>
+
#include <asm/uaccess.h>
#include <asm/ipc.h>
#include <asm/semaphore.h>
@@ -84,6 +86,8 @@

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

ret = -EINVAL;
switch (call) {
diff -urN linux-2.5.33/arch/ppc/kernel/time.c linux-2.5.33-ltt/arch/ppc/kernel/time.c
--- linux-2.5.33/arch/ppc/kernel/time.c Sat Aug 31 18:04:52 2002
+++ linux-2.5.33-ltt/arch/ppc/kernel/time.c Fri Sep 6 14:26:12 2002
@@ -60,6 +60,8 @@
#include <linux/time.h>
#include <linux/init.h>

+#include <linux/trace.h>
+
#include <asm/segment.h>
#include <asm/io.h>
#include <asm/processor.h>
@@ -161,6 +163,8 @@
if (atomic_read(&ppc_n_lost_interrupts) != 0)
do_IRQ(regs);

+ TRACE_TRAP_ENTRY(regs->trap, instruction_pointer(regs));
+
irq_enter();

while ((next_dec = tb_ticks_per_jiffy - tb_delta(&jiffy_stamp)) < 0) {
@@ -215,6 +219,8 @@
ppc_md.heartbeat();

irq_exit();
+
+ TRACE_TRAP_EXIT();
}
#endif /* CONFIG_PPC_ISERIES */

diff -urN linux-2.5.33/arch/ppc/kernel/traps.c linux-2.5.33-ltt/arch/ppc/kernel/traps.c
--- linux-2.5.33/arch/ppc/kernel/traps.c Sat Aug 31 18:04:52 2002
+++ linux-2.5.33-ltt/arch/ppc/kernel/traps.c Fri Sep 6 12:03:20 2002
@@ -33,6 +33,8 @@
#include <linux/config.h>
#include <linux/init.h>

+#include <linux/trace.h>
+
#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/system.h>
@@ -111,7 +113,9 @@
debugger(regs);
die("Exception in kernel mode", regs, signr);
}
+ TRACE_TRAP_ENTRY(regs->trap, instruction_pointer(regs));
force_sig(signr, current);
+ TRACE_TRAP_EXIT();
}

void
@@ -369,6 +373,89 @@
show_regs(regs);
panic("kernel stack overflow");
}
+
+/* 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->gpr[0];
+
+ /* Set the address in any case */
+ trace_syscall_event.address = instruction_pointer(regs);
+
+ /* Are we in the kernel (This is a kernel thread)? */
+ if(!user_mode(regs))
+ /* 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->gpr[1];
+
+ /* Skip over first stack frame as the return address isn't valid */
+ if(get_user(addr, stack))
+ goto trace_syscall_end;
+ stack = (unsigned long*) addr;
+
+ /* Keep on going until we reach the end of the process' stack limit (wherever it may be) */
+ while(!get_user(addr, stack + 1)) /* "stack + 1", since this is where the IP is */
+ {
+ /* 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 */
+ if(get_user(addr, stack))
+ goto trace_syscall_end;
+ stack = (unsigned long*) addr;
+ }
+ }
+
+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) */

void nonrecoverable_exception(struct pt_regs *regs)
{
diff -urN linux-2.5.33/arch/ppc/mm/fault.c linux-2.5.33-ltt/arch/ppc/mm/fault.c
--- linux-2.5.33/arch/ppc/mm/fault.c Sat Aug 31 18:04:54 2002
+++ linux-2.5.33-ltt/arch/ppc/mm/fault.c Fri Sep 6 12:03:20 2002
@@ -31,6 +31,8 @@
#include <linux/interrupt.h>
#include <linux/highmem.h>

+#include <linux/trace.h>
+
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
@@ -88,22 +90,28 @@
is_write = error_code & 0x02000000;
#endif /* CONFIG_4xx */

+ TRACE_TRAP_ENTRY(regs->trap, instruction_pointer(regs));
+
#if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
if (debugger_fault_handler && TRAP(regs) == 0x300) {
debugger_fault_handler(regs);
+ TRACE_TRAP_EXIT();
return;
}
#if !defined(CONFIG_4xx)
if (error_code & 0x00400000) {
/* DABR match */
- if (debugger_dabr_match(regs))
+ if (debugger_dabr_match(regs)){
+ TRACE_TRAP_EXIT();
return;
+ }
}
#endif /* !CONFIG_4xx */
#endif /* CONFIG_XMON || CONFIG_KGDB */

if (in_interrupt() || mm == NULL) {
bad_page_fault(regs, address, SIGSEGV);
+ TRACE_TRAP_EXIT();
return;
}
down_read(&mm->mmap_sem);
@@ -168,6 +176,7 @@
_tlbie(address);
pte_unmap(ptep);
up_read(&mm->mmap_sem);
+ TRACE_TRAP_EXIT();
return;
}
if (ptep != NULL)
@@ -210,6 +219,7 @@
* -- Cort
*/
pte_misses++;
+ TRACE_TRAP_EXIT();
return;

bad_area:
@@ -223,10 +233,12 @@
info.si_code = code;
info.si_addr = (void *) address;
force_sig_info(SIGSEGV, &info, current);
+ TRACE_TRAP_EXIT();
return;
}

bad_page_fault(regs, address, SIGSEGV);
+ TRACE_TRAP_EXIT();
return;

/*
@@ -244,6 +256,7 @@
if (user_mode(regs))
do_exit(SIGKILL);
bad_page_fault(regs, address, SIGKILL);
+ TRACE_TRAP_EXIT();
return;

do_sigbus:
@@ -255,6 +268,7 @@
force_sig_info (SIGBUS, &info, current);
if (!user_mode(regs))
bad_page_fault(regs, address, SIGBUS);
+ TRACE_TRAP_EXIT();
}

/*
diff -urN linux-2.5.33/include/asm-ppc/trace.h linux-2.5.33-ltt/include/asm-ppc/trace.h
--- linux-2.5.33/include/asm-ppc/trace.h Wed Dec 31 19:00:00 1969
+++ linux-2.5.33-ltt/include/asm-ppc/trace.h Fri Sep 6 12:03:21 2002
@@ -0,0 +1,30 @@
+/*
+ * linux/include/asm-ppc/trace.h
+ *
+ * Copyright (C) 2002, Karim Yaghmour
+ *
+ * PowerPC definitions for tracing system
+ */
+
+#include <linux/config.h>
+#include <linux/trace.h>
+
+/* Current arch type */
+#define TRACE_ARCH_TYPE TRACE_ARCH_TYPE_PPC
+
+/* PowerPC variants */
+#define TRACE_ARCH_VARIANT_PPC_4xx 1 /* 4xx systems (IBM embedded series) */
+#define TRACE_ARCH_VARIANT_PPC_6xx 2 /* 6xx/7xx/74xx/8260/POWER3 systems (desktop flavor) */
+#define TRACE_ARCH_VARIANT_PPC_8xx 3 /* 8xx system (Motoral embedded series) */
+#define TRACE_ARCH_VARIANT_PPC_ISERIES 4 /* 8xx system (iSeries) */
+
+/* Current variant type */
+#if defined(CONFIG_4xx)
+#define TRACE_ARCH_VARIANT TRACE_ARCH_VARIANT_PPC_4xx
+#elif defined(CONFIG_6xx)
+#define TRACE_ARCH_VARIANT TRACE_ARCH_VARIANT_PPC_6xx
+#elif defined(CONFIG_8xx)
+#define TRACE_ARCH_VARIANT TRACE_ARCH_VARIANT_PPC_8xx
+#elif defined(CONFIG_PPC_ISERIES)
+#define TRACE_ARCH_VARIANT TRACE_ARCH_VARIANT_PPC_ISERIES
+#endif
-
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