Paul,
This patch series addresses the issues you brought up as well as
adds some more enhancements and fixes. This series is added on
top of the previous patch series.
The new patches are: (and are posted now)
5987225... powerpc/ppc32: static ftrace fixes for PPC32
382d6db... powerpc: ftrace, use create_branch
d7d0ab8... powerpc: ftrace, added missing icache flush
10ec622... powerpc: ftrace, fix cast aliasing and add code verification
d208ca5... powerpc: ftrace, do nothing in mcount call for dyn ftrace
The patches you already commented on:
5c4f5d7... powerpc/ppc32: ftrace, dynamic ftrace to handle modules
a73af3e... powerpc/ppc64: ftrace, handle module trampolines for dyn ftrace
009104f... powerpc: ftrace, use probe_kernel API to modify code
a352036... powerpc: ftrace, convert to new dynamic ftrace arch API
6d07bb4... powerpc: ftrace, do not latency trace idle
Note, I also fixed the spelling of your name in the change log of commit
a352036... powerpc: ftrace, convert to new dynamic ftrace arch API
I'm only posting the new patches. I've tested this on both my
PPC64 and my PPC32 boxes. You can test this as well by checking out
my tip/ppc branch which is based off of an older version of tip
and has the ppc dynamic ftrace code enabled. That branch is not to pull
from, but is there for you to try out this code if you like.
The previous patch series, which have not changed except for the
spelling fix of Paul's last name, can be found here:
http://lkml.org/lkml/2008/11/20/356
The following patches are in:
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
branch: ppc/ftrace
Steven Rostedt (5):
powerpc: ftrace, do nothing in mcount call for dyn ftrace
powerpc: ftrace, fix cast aliasing and add code verification
powerpc: ftrace, added missing icache flush
powerpc: ftrace, use create_branch
powerpc/ppc32: static ftrace fixes for PPC32
----
arch/powerpc/kernel/Makefile | 1 +
arch/powerpc/kernel/entry_32.S | 40 ++-------
arch/powerpc/kernel/entry_64.S | 12 ---
arch/powerpc/kernel/ftrace.c | 182 +++++++++++++++++++---------------------
arch/powerpc/lib/Makefile | 3 +
5 files changed, 98 insertions(+), 140 deletions(-)
On Wed, 26 Nov 2008, Steven Rostedt wrote:
> Paul,
>
> This patch series addresses the issues you brought up as well as
> adds some more enhancements and fixes. This series is added on
> top of the previous patch series.
>
> The new patches are: (and are posted now)
> 5987225... powerpc/ppc32: static ftrace fixes for PPC32
The new commit id with the fix in Author and SoB is:
fd90db4bdc1ccf71927365cd634188cec4d7b151
powerpc/ppc32: static ftrace fixes for
-- Steve
> 382d6db... powerpc: ftrace, use create_branch
> d7d0ab8... powerpc: ftrace, added missing icache flush
> 10ec622... powerpc: ftrace, fix cast aliasing and add code verification
> d208ca5... powerpc: ftrace, do nothing in mcount call for dyn ftrace
>
> The patches you already commented on:
> 5c4f5d7... powerpc/ppc32: ftrace, dynamic ftrace to handle modules
> a73af3e... powerpc/ppc64: ftrace, handle module trampolines for dyn ftrace
> 009104f... powerpc: ftrace, use probe_kernel API to modify code
> a352036... powerpc: ftrace, convert to new dynamic ftrace arch API
> 6d07bb4... powerpc: ftrace, do not latency trace idle
>
* Steven Rostedt <[email protected]> wrote:
> On Wed, 26 Nov 2008, Steven Rostedt wrote:
>
> > Paul,
> >
> > This patch series addresses the issues you brought up as well as
> > adds some more enhancements and fixes. This series is added on
> > top of the previous patch series.
> >
> > The new patches are: (and are posted now)
> > 5987225... powerpc/ppc32: static ftrace fixes for PPC32
>
> The new commit id with the fix in Author and SoB is:
> fd90db4bdc1ccf71927365cd634188cec4d7b151
> powerpc/ppc32: static ftrace fixes for
Steve, you rebased the previous commits, and that's a no-no. I sorted it
all out, find below the stable URI for stuff that we'd like Paul to pull
shortly before the merge window.
Thanks,
Ingo
-------------------------->
Please pull the latest tracing/powerpc git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git tracing/powerpc
Thanks,
Ingo
------------------>
Steven Rostedt (10):
powerpc: ftrace, do not latency trace idle
powerpc: ftrace, convert to new dynamic ftrace arch API
powerpc: ftrace, use probe_kernel API to modify code
powerpc/ppc64: ftrace, handle module trampolines for dyn ftrace
powerpc/ppc32: ftrace, dynamic ftrace to handle modules
powerpc: ftrace, do nothing in mcount call for dyn ftrace
powerpc: ftrace, fix cast aliasing and add code verification
powerpc: ftrace, added missing icache flush
powerpc: ftrace, use create_branch
powerpc/ppc32: static ftrace fixes for PPC32
arch/powerpc/include/asm/ftrace.h | 14 +-
arch/powerpc/include/asm/module.h | 16 ++-
arch/powerpc/kernel/Makefile | 1 +
arch/powerpc/kernel/entry_32.S | 40 +---
arch/powerpc/kernel/entry_64.S | 12 -
arch/powerpc/kernel/ftrace.c | 461 +++++++++++++++++++++++++++++++++----
arch/powerpc/kernel/idle.c | 5 +
arch/powerpc/kernel/module_32.c | 10 +
arch/powerpc/kernel/module_64.c | 13 +
arch/powerpc/lib/Makefile | 3 +
10 files changed, 490 insertions(+), 85 deletions(-)
diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h
index b298f7a..e5f2ae8 100644
--- a/arch/powerpc/include/asm/ftrace.h
+++ b/arch/powerpc/include/asm/ftrace.h
@@ -7,7 +7,19 @@
#ifndef __ASSEMBLY__
extern void _mcount(void);
-#endif
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+static inline unsigned long ftrace_call_adjust(unsigned long addr)
+{
+ /* reloction of mcount call site is the same as the address */
+ return addr;
+}
+
+struct dyn_arch_ftrace {
+ struct module *mod;
+};
+#endif /* CONFIG_DYNAMIC_FTRACE */
+#endif /* __ASSEMBLY__ */
#endif
diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
index e5f14b1..0845488 100644
--- a/arch/powerpc/include/asm/module.h
+++ b/arch/powerpc/include/asm/module.h
@@ -34,11 +34,19 @@ struct mod_arch_specific {
#ifdef __powerpc64__
unsigned int stubs_section; /* Index of stubs section in module */
unsigned int toc_section; /* What section is the TOC? */
-#else
+#ifdef CONFIG_DYNAMIC_FTRACE
+ unsigned long toc;
+ unsigned long tramp;
+#endif
+
+#else /* powerpc64 */
/* Indices of PLT sections within module. */
unsigned int core_plt_section;
unsigned int init_plt_section;
+#ifdef CONFIG_DYNAMIC_FTRACE
+ unsigned long tramp;
#endif
+#endif /* powerpc64 */
/* List of BUG addresses, source line numbers and filenames */
struct list_head bug_list;
@@ -68,6 +76,12 @@ struct mod_arch_specific {
# endif /* MODULE */
#endif
+#ifdef CONFIG_DYNAMIC_FTRACE
+# ifdef MODULE
+ asm(".section .ftrace.tramp,\"ax\",@nobits; .align 3; .previous");
+# endif /* MODULE */
+#endif
+
struct exception_table_entry;
void sort_ex_table(struct exception_table_entry *start,
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 92673b4..d17edb4 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -17,6 +17,7 @@ ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_cputable.o = -pg -mno-sched-epilog
CFLAGS_REMOVE_prom_init.o = -pg -mno-sched-epilog
CFLAGS_REMOVE_btext.o = -pg -mno-sched-epilog
+CFLAGS_REMOVE_prom.o = -pg -mno-sched-epilog
ifdef CONFIG_DYNAMIC_FTRACE
# dynamic ftrace setup.
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 7ecc0d1..6f7eb7e 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1162,39 +1162,17 @@ machine_check_in_rtas:
#ifdef CONFIG_DYNAMIC_FTRACE
_GLOBAL(mcount)
_GLOBAL(_mcount)
- stwu r1,-48(r1)
- stw r3, 12(r1)
- stw r4, 16(r1)
- stw r5, 20(r1)
- stw r6, 24(r1)
- mflr r3
- stw r7, 28(r1)
- mfcr r5
- stw r8, 32(r1)
- stw r9, 36(r1)
- stw r10,40(r1)
- stw r3, 44(r1)
- stw r5, 8(r1)
- subi r3, r3, MCOUNT_INSN_SIZE
- .globl mcount_call
-mcount_call:
- bl ftrace_stub
- nop
- lwz r6, 8(r1)
- lwz r0, 44(r1)
- lwz r3, 12(r1)
+ /*
+ * It is required that _mcount on PPC32 must preserve the
+ * link register. But we have r0 to play with. We use r0
+ * to push the return address back to the caller of mcount
+ * into the ctr register, restore the link register and
+ * then jump back using the ctr register.
+ */
+ mflr r0
mtctr r0
- lwz r4, 16(r1)
- mtcr r6
- lwz r5, 20(r1)
- lwz r6, 24(r1)
- lwz r0, 52(r1)
- lwz r7, 28(r1)
- lwz r8, 32(r1)
+ lwz r0, 4(r1)
mtlr r0
- lwz r9, 36(r1)
- lwz r10,40(r1)
- addi r1, r1, 48
bctr
_GLOBAL(ftrace_caller)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index e6d5284..b00982e 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -888,18 +888,6 @@ _GLOBAL(enter_prom)
#ifdef CONFIG_DYNAMIC_FTRACE
_GLOBAL(mcount)
_GLOBAL(_mcount)
- /* Taken from output of objdump from lib64/glibc */
- mflr r3
- stdu r1, -112(r1)
- std r3, 128(r1)
- subi r3, r3, MCOUNT_INSN_SIZE
- .globl mcount_call
-mcount_call:
- bl ftrace_stub
- nop
- ld r0, 128(r1)
- mtlr r0
- addi r1, r1, 112
blr
_GLOBAL(ftrace_caller)
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index f4b006e..5355244 100644
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c
@@ -9,22 +9,30 @@
#include <linux/spinlock.h>
#include <linux/hardirq.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
#include <linux/ftrace.h>
#include <linux/percpu.h>
#include <linux/init.h>
#include <linux/list.h>
#include <asm/cacheflush.h>
+#include <asm/code-patching.h>
#include <asm/ftrace.h>
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(fmt , ...) do { } while (0)
+#endif
-static unsigned int ftrace_nop = 0x60000000;
+static unsigned int ftrace_nop = PPC_NOP_INSTR;
#ifdef CONFIG_PPC32
# define GET_ADDR(addr) addr
#else
/* PowerPC64's functions are data that points to the functions */
-# define GET_ADDR(addr) *(unsigned long *)addr
+# define GET_ADDR(addr) (*(unsigned long *)addr)
#endif
@@ -33,12 +41,12 @@ static unsigned int ftrace_calc_offset(long ip, long addr)
return (int)(addr - ip);
}
-unsigned char *ftrace_nop_replace(void)
+static unsigned char *ftrace_nop_replace(void)
{
return (char *)&ftrace_nop;
}
-unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
+static unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
{
static unsigned int op;
@@ -68,49 +76,422 @@ unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
# define _ASM_PTR " .long "
#endif
-int
+static int
ftrace_modify_code(unsigned long ip, unsigned char *old_code,
unsigned char *new_code)
{
- unsigned replaced;
- unsigned old = *(unsigned *)old_code;
- unsigned new = *(unsigned *)new_code;
- int faulted = 0;
+ unsigned char replaced[MCOUNT_INSN_SIZE];
/*
* Note: Due to modules and __init, code can
* disappear and change, we need to protect against faulting
- * as well as code changing.
+ * as well as code changing. We do this by using the
+ * probe_kernel_* functions.
*
* No real locking needed, this code is run through
- * kstop_machine.
+ * kstop_machine, or before SMP starts.
*/
- asm volatile (
- "1: lwz %1, 0(%2)\n"
- " cmpw %1, %5\n"
- " bne 2f\n"
- " stwu %3, 0(%2)\n"
- "2:\n"
- ".section .fixup, \"ax\"\n"
- "3: li %0, 1\n"
- " b 2b\n"
- ".previous\n"
- ".section __ex_table,\"a\"\n"
- _ASM_ALIGN "\n"
- _ASM_PTR "1b, 3b\n"
- ".previous"
- : "=r"(faulted), "=r"(replaced)
- : "r"(ip), "r"(new),
- "0"(faulted), "r"(old)
- : "memory");
-
- if (replaced != old && replaced != new)
- faulted = 2;
-
- if (!faulted)
- flush_icache_range(ip, ip + 8);
-
- return faulted;
+
+ /* read the text we want to modify */
+ if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ /* Make sure it is what we expect it to be */
+ if (memcmp(replaced, old_code, MCOUNT_INSN_SIZE) != 0)
+ return -EINVAL;
+
+ /* replace the text with the new text */
+ if (probe_kernel_write((void *)ip, new_code, MCOUNT_INSN_SIZE))
+ return -EPERM;
+
+ flush_icache_range(ip, ip + 8);
+
+ return 0;
+}
+
+/*
+ * Helper functions that are the same for both PPC64 and PPC32.
+ */
+static int test_24bit_addr(unsigned long ip, unsigned long addr)
+{
+
+ /* use the create_branch to verify that this offset can be branched */
+ return create_branch((unsigned int *)ip, addr, 0);
+}
+
+static int is_bl_op(unsigned int op)
+{
+ return (op & 0xfc000003) == 0x48000001;
+}
+
+static unsigned long find_bl_target(unsigned long ip, unsigned int op)
+{
+ static int offset;
+
+ offset = (op & 0x03fffffc);
+ /* make it signed */
+ if (offset & 0x02000000)
+ offset |= 0xfe000000;
+
+ return ip + (long)offset;
+}
+
+#ifdef CONFIG_PPC64
+static int
+__ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned int op;
+ unsigned int jmp[5];
+ unsigned long ptr;
+ unsigned long ip = rec->ip;
+ unsigned long tramp;
+ int offset;
+
+ /* read where this goes */
+ if (probe_kernel_read(&op, (void *)ip, sizeof(int)))
+ return -EFAULT;
+
+ /* Make sure that that this is still a 24bit jump */
+ if (!is_bl_op(op)) {
+ printk(KERN_ERR "Not expected bl: opcode is %x\n", op);
+ return -EINVAL;
+ }
+
+ /* lets find where the pointer goes */
+ tramp = find_bl_target(ip, op);
+
+ /*
+ * On PPC64 the trampoline looks like:
+ * 0x3d, 0x82, 0x00, 0x00, addis r12,r2, <high>
+ * 0x39, 0x8c, 0x00, 0x00, addi r12,r12, <low>
+ * Where the bytes 2,3,6 and 7 make up the 32bit offset
+ * to the TOC that holds the pointer.
+ * to jump to.
+ * 0xf8, 0x41, 0x00, 0x28, std r2,40(r1)
+ * 0xe9, 0x6c, 0x00, 0x20, ld r11,32(r12)
+ * The actually address is 32 bytes from the offset
+ * into the TOC.
+ * 0xe8, 0x4c, 0x00, 0x28, ld r2,40(r12)
+ */
+
+ DEBUGP("ip:%lx jumps to %lx r2: %lx", ip, tramp, mod->arch.toc);
+
+ /* Find where the trampoline jumps to */
+ if (probe_kernel_read(jmp, (void *)tramp, sizeof(jmp))) {
+ printk(KERN_ERR "Failed to read %lx\n", tramp);
+ return -EFAULT;
+ }
+
+ DEBUGP(" %08x %08x", jmp[0], jmp[1]);
+
+ /* verify that this is what we expect it to be */
+ if (((jmp[0] & 0xffff0000) != 0x3d820000) ||
+ ((jmp[1] & 0xffff0000) != 0x398c0000) ||
+ (jmp[2] != 0xf8410028) ||
+ (jmp[3] != 0xe96c0020) ||
+ (jmp[4] != 0xe84c0028)) {
+ printk(KERN_ERR "Not a trampoline\n");
+ return -EINVAL;
+ }
+
+ offset = (unsigned)((unsigned short)jmp[0]) << 16 |
+ (unsigned)((unsigned short)jmp[1]);
+
+ DEBUGP(" %x ", offset);
+
+ /* get the address this jumps too */
+ tramp = mod->arch.toc + offset + 32;
+ DEBUGP("toc: %lx", tramp);
+
+ if (probe_kernel_read(jmp, (void *)tramp, 8)) {
+ printk(KERN_ERR "Failed to read %lx\n", tramp);
+ return -EFAULT;
+ }
+
+ DEBUGP(" %08x %08x\n", jmp[0], jmp[1]);
+
+ ptr = ((unsigned long)jmp[0] << 32) + jmp[1];
+
+ /* This should match what was called */
+ if (ptr != GET_ADDR(addr)) {
+ printk(KERN_ERR "addr does not match %lx\n", ptr);
+ return -EINVAL;
+ }
+
+ /*
+ * We want to nop the line, but the next line is
+ * 0xe8, 0x41, 0x00, 0x28 ld r2,40(r1)
+ * This needs to be turned to a nop too.
+ */
+ if (probe_kernel_read(&op, (void *)(ip+4), MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ if (op != 0xe8410028) {
+ printk(KERN_ERR "Next line is not ld! (%08x)\n", op);
+ return -EINVAL;
+ }
+
+ /*
+ * Milton Miller pointed out that we can not blindly do nops.
+ * If a task was preempted when calling a trace function,
+ * the nops will remove the way to restore the TOC in r2
+ * and the r2 TOC will get corrupted.
+ */
+
+ /*
+ * Replace:
+ * bl <tramp> <==== will be replaced with "b 1f"
+ * ld r2,40(r1)
+ * 1:
+ */
+ op = 0x48000008; /* b +8 */
+
+ if (probe_kernel_write((void *)ip, &op, MCOUNT_INSN_SIZE))
+ return -EPERM;
+
+
+ flush_icache_range(ip, ip + 8);
+
+ return 0;
+}
+
+#else /* !PPC64 */
+static int
+__ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned int op;
+ unsigned int jmp[4];
+ unsigned long ip = rec->ip;
+ unsigned long tramp;
+
+ if (probe_kernel_read(&op, (void *)ip, MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ /* Make sure that that this is still a 24bit jump */
+ if (!is_bl_op(op)) {
+ printk(KERN_ERR "Not expected bl: opcode is %x\n", op);
+ return -EINVAL;
+ }
+
+ /* lets find where the pointer goes */
+ tramp = find_bl_target(ip, op);
+
+ /*
+ * On PPC32 the trampoline looks like:
+ * 0x3d, 0x60, 0x00, 0x00 lis r11,sym@ha
+ * 0x39, 0x6b, 0x00, 0x00 addi r11,r11,sym@l
+ * 0x7d, 0x69, 0x03, 0xa6 mtctr r11
+ * 0x4e, 0x80, 0x04, 0x20 bctr
+ */
+
+ DEBUGP("ip:%lx jumps to %lx", ip, tramp);
+
+ /* Find where the trampoline jumps to */
+ if (probe_kernel_read(jmp, (void *)tramp, sizeof(jmp))) {
+ printk(KERN_ERR "Failed to read %lx\n", tramp);
+ return -EFAULT;
+ }
+
+ DEBUGP(" %08x %08x ", jmp[0], jmp[1]);
+
+ /* verify that this is what we expect it to be */
+ if (((jmp[0] & 0xffff0000) != 0x3d600000) ||
+ ((jmp[1] & 0xffff0000) != 0x396b0000) ||
+ (jmp[2] != 0x7d6903a6) ||
+ (jmp[3] != 0x4e800420)) {
+ printk(KERN_ERR "Not a trampoline\n");
+ return -EINVAL;
+ }
+
+ tramp = (jmp[1] & 0xffff) |
+ ((jmp[0] & 0xffff) << 16);
+ if (tramp & 0x8000)
+ tramp -= 0x10000;
+
+ DEBUGP(" %x ", tramp);
+
+ if (tramp != addr) {
+ printk(KERN_ERR
+ "Trampoline location %08lx does not match addr\n",
+ tramp);
+ return -EINVAL;
+ }
+
+ op = PPC_NOP_INSTR;
+
+ if (probe_kernel_write((void *)ip, &op, MCOUNT_INSN_SIZE))
+ return -EPERM;
+
+ flush_icache_range(ip, ip + 8);
+
+ return 0;
+}
+#endif /* PPC64 */
+
+int ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char *old, *new;
+ unsigned long ip = rec->ip;
+
+ /*
+ * If the calling address is more that 24 bits away,
+ * then we had to use a trampoline to make the call.
+ * Otherwise just update the call site.
+ */
+ if (test_24bit_addr(ip, addr)) {
+ /* within range */
+ old = ftrace_call_replace(ip, addr);
+ new = ftrace_nop_replace();
+ return ftrace_modify_code(ip, old, new);
+ }
+
+ /*
+ * Out of range jumps are called from modules.
+ * We should either already have a pointer to the module
+ * or it has been passed in.
+ */
+ if (!rec->arch.mod) {
+ if (!mod) {
+ printk(KERN_ERR "No module loaded addr=%lx\n",
+ addr);
+ return -EFAULT;
+ }
+ rec->arch.mod = mod;
+ } else if (mod) {
+ if (mod != rec->arch.mod) {
+ printk(KERN_ERR
+ "Record mod %p not equal to passed in mod %p\n",
+ rec->arch.mod, mod);
+ return -EINVAL;
+ }
+ /* nothing to do if mod == rec->arch.mod */
+ } else
+ mod = rec->arch.mod;
+
+ return __ftrace_make_nop(mod, rec, addr);
+
+}
+
+#ifdef CONFIG_PPC64
+static int
+__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned int op[2];
+ unsigned long ip = rec->ip;
+
+ /* read where this goes */
+ if (probe_kernel_read(op, (void *)ip, MCOUNT_INSN_SIZE * 2))
+ return -EFAULT;
+
+ /*
+ * It should be pointing to two nops or
+ * b +8; ld r2,40(r1)
+ */
+ if (((op[0] != 0x48000008) || (op[1] != 0xe8410028)) &&
+ ((op[0] != PPC_NOP_INSTR) || (op[1] != PPC_NOP_INSTR))) {
+ printk(KERN_ERR "Expected NOPs but have %x %x\n", op[0], op[1]);
+ return -EINVAL;
+ }
+
+ /* If we never set up a trampoline to ftrace_caller, then bail */
+ if (!rec->arch.mod->arch.tramp) {
+ printk(KERN_ERR "No ftrace trampoline\n");
+ return -EINVAL;
+ }
+
+ /* create the branch to the trampoline */
+ op[0] = create_branch((unsigned int *)ip,
+ rec->arch.mod->arch.tramp, BRANCH_SET_LINK);
+ if (!op[0]) {
+ printk(KERN_ERR "REL24 out of range!\n");
+ return -EINVAL;
+ }
+
+ /* ld r2,40(r1) */
+ op[1] = 0xe8410028;
+
+ DEBUGP("write to %lx\n", rec->ip);
+
+ if (probe_kernel_write((void *)ip, op, MCOUNT_INSN_SIZE * 2))
+ return -EPERM;
+
+ flush_icache_range(ip, ip + 8);
+
+ return 0;
+}
+#else
+static int
+__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned int op;
+ unsigned long ip = rec->ip;
+
+ /* read where this goes */
+ if (probe_kernel_read(&op, (void *)ip, MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ /* It should be pointing to a nop */
+ if (op != PPC_NOP_INSTR) {
+ printk(KERN_ERR "Expected NOP but have %x\n", op);
+ return -EINVAL;
+ }
+
+ /* If we never set up a trampoline to ftrace_caller, then bail */
+ if (!rec->arch.mod->arch.tramp) {
+ printk(KERN_ERR "No ftrace trampoline\n");
+ return -EINVAL;
+ }
+
+ /* create the branch to the trampoline */
+ op = create_branch((unsigned int *)ip,
+ rec->arch.mod->arch.tramp, BRANCH_SET_LINK);
+ if (!op) {
+ printk(KERN_ERR "REL24 out of range!\n");
+ return -EINVAL;
+ }
+
+ DEBUGP("write to %lx\n", rec->ip);
+
+ if (probe_kernel_write((void *)ip, &op, MCOUNT_INSN_SIZE))
+ return -EPERM;
+
+ flush_icache_range(ip, ip + 8);
+
+ return 0;
+}
+#endif /* CONFIG_PPC64 */
+
+int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char *old, *new;
+ unsigned long ip = rec->ip;
+
+ /*
+ * If the calling address is more that 24 bits away,
+ * then we had to use a trampoline to make the call.
+ * Otherwise just update the call site.
+ */
+ if (test_24bit_addr(ip, addr)) {
+ /* within range */
+ old = ftrace_nop_replace();
+ new = ftrace_call_replace(ip, addr);
+ return ftrace_modify_code(ip, old, new);
+ }
+
+ /*
+ * Out of range jumps are called from modules.
+ * Being that we are converting from nop, it had better
+ * already have a module defined.
+ */
+ if (!rec->arch.mod) {
+ printk(KERN_ERR "No module loaded\n");
+ return -EINVAL;
+ }
+
+ return __ftrace_make_call(rec, addr);
}
int ftrace_update_ftrace_func(ftrace_func_t func)
@@ -128,10 +509,10 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
int __init ftrace_dyn_arch_init(void *data)
{
- /* This is running in kstop_machine */
+ /* caller expects data to be zero */
+ unsigned long *p = data;
- ftrace_mcount_set(data);
+ *p = 0;
return 0;
}
-
diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c
index 31982d0..88d9c1d 100644
--- a/arch/powerpc/kernel/idle.c
+++ b/arch/powerpc/kernel/idle.c
@@ -69,10 +69,15 @@ void cpu_idle(void)
smp_mb();
local_irq_disable();
+ /* Don't trace irqs off for idle */
+ stop_critical_timings();
+
/* check again after disabling irqs */
if (!need_resched() && !cpu_should_die())
ppc_md.power_save();
+ start_critical_timings();
+
local_irq_enable();
set_thread_flag(TIF_POLLING_NRFLAG);
diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c
index 2df91a0..f832773 100644
--- a/arch/powerpc/kernel/module_32.c
+++ b/arch/powerpc/kernel/module_32.c
@@ -22,6 +22,7 @@
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
+#include <linux/ftrace.h>
#include <linux/cache.h>
#include <linux/bug.h>
#include <linux/sort.h>
@@ -53,6 +54,9 @@ static unsigned int count_relocs(const Elf32_Rela *rela, unsigned int num)
r_addend = rela[i].r_addend;
}
+#ifdef CONFIG_DYNAMIC_FTRACE
+ _count_relocs++; /* add one for ftrace_caller */
+#endif
return _count_relocs;
}
@@ -306,5 +310,11 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
return -ENOEXEC;
}
}
+#ifdef CONFIG_DYNAMIC_FTRACE
+ module->arch.tramp =
+ do_plt_call(module->module_core,
+ (unsigned long)ftrace_caller,
+ sechdrs, module);
+#endif
return 0;
}
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 1af2377..8992b03 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -20,6 +20,7 @@
#include <linux/moduleloader.h>
#include <linux/err.h>
#include <linux/vmalloc.h>
+#include <linux/ftrace.h>
#include <linux/bug.h>
#include <asm/module.h>
#include <asm/firmware.h>
@@ -163,6 +164,11 @@ static unsigned long get_stubs_size(const Elf64_Ehdr *hdr,
}
}
+#ifdef CONFIG_DYNAMIC_FTRACE
+ /* make the trampoline to the ftrace_caller */
+ relocs++;
+#endif
+
DEBUGP("Looks like a total of %lu stubs, max\n", relocs);
return relocs * sizeof(struct ppc64_stub_entry);
}
@@ -441,5 +447,12 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
}
}
+#ifdef CONFIG_DYNAMIC_FTRACE
+ me->arch.toc = my_r2(sechdrs, me);
+ me->arch.tramp = stub_for_addr(sechdrs,
+ (unsigned long)ftrace_caller,
+ me);
+#endif
+
return 0;
}
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index d69912c..8db3527 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -6,6 +6,9 @@ ifeq ($(CONFIG_PPC64),y)
EXTRA_CFLAGS += -mno-minimal-toc
endif
+CFLAGS_REMOVE_code-patching.o = -pg
+CFLAGS_REMOVE_feature-fixups.o = -pg
+
obj-y := string.o alloc.o \
checksum_$(CONFIG_WORD_SIZE).o
obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o
On Fri, 28 Nov 2008, Ingo Molnar wrote:
>
> * Steven Rostedt <[email protected]> wrote:
>
> > On Wed, 26 Nov 2008, Steven Rostedt wrote:
> >
> > > Paul,
> > >
> > > This patch series addresses the issues you brought up as well as
> > > adds some more enhancements and fixes. This series is added on
> > > top of the previous patch series.
> > >
> > > The new patches are: (and are posted now)
> > > 5987225... powerpc/ppc32: static ftrace fixes for PPC32
> >
> > The new commit id with the fix in Author and SoB is:
> > fd90db4bdc1ccf71927365cd634188cec4d7b151
> > powerpc/ppc32: static ftrace fixes for
>
> Steve, you rebased the previous commits, and that's a no-no. I sorted it
> all out, find below the stable URI for stuff that we'd like Paul to pull
> shortly before the merge window.
Sorry, I rebased to edit the change log where I mispelled Paul's name.
-- Steve
Steven Rostedt writes:
> Sorry, I rebased to edit the change log where I mispelled Paul's name.
So, what commits should I be pulling into powerpc.git, or what patches
should I be committing, for dynamic ftrace on powerpc?
Paul.
On Fri, 19 Dec 2008, Paul Mackerras wrote:
> Steven Rostedt writes:
>
> > Sorry, I rebased to edit the change log where I mispelled Paul's name.
>
> So, what commits should I be pulling into powerpc.git, or what patches
> should I be committing, for dynamic ftrace on powerpc?
Ingo did not like the rebase and kept the original commits (the one with
the change log with the incorrect spelling).
From: git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git
tracing/powerpc
====================================
commit 8fd6e5a8c81e2e9b912ea33c8425a10729db469b
Author: Steven Rostedt <[email protected]>
Date: Fri Nov 14 16:21:19 2008 -0800
powerpc: ftrace, convert to new dynamic ftrace arch API
Impact: update to PowerPC ftrace arch API
This patch converts PowerPC to use the new dynamic ftrace arch API.
Thanks to Paul Mackennas for pointing out the mistakes of my original
test_24bit_addr function.
Signed-off-by: Steven Rostedt <[email protected]>
====================================
The branch in my tree 'ppc/ftrace' has not been changed since. The only
reason the commits in my tree are different than the ones in tip was
because I rebased to fixed the spelling in the change log.
From: git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
ppc/ftrace
====================================
commit a3520364f9376943e4d6c76931bf4df8569fa555
Author: Steven Rostedt <[email protected]>
Date: Fri Nov 14 16:21:19 2008 -0800
powerpc: ftrace, convert to new dynamic ftrace arch API
Impact: update to PowerPC ftrace arch API
This patch converts PowerPC to use the new dynamic ftrace arch API.
Thanks to Paul Mackerras for pointing out the mistakes of my original
test_24bit_addr function.
Signed-off-by: Steven Rostedt <[email protected]>
====================================
Take your pick for which to pull from.
Thanks,
-- Steve