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-rw-r--r--arch/powerpc/include/asm/ftrace.h14
-rw-r--r--arch/powerpc/include/asm/module.h16
-rw-r--r--arch/powerpc/kernel/ftrace.c473
-rw-r--r--arch/powerpc/kernel/idle.c5
-rw-r--r--arch/powerpc/kernel/module_32.c10
-rw-r--r--arch/powerpc/kernel/module_64.c13
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--arch/x86/include/asm/ftrace.h1
-rw-r--r--arch/x86/include/asm/thread_info.h29
-rw-r--r--arch/x86/kernel/ftrace.c29
-rw-r--r--arch/x86/kernel/stacktrace.c64
11 files changed, 569 insertions, 86 deletions
diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h
index b298f7a631e6..e5f2ae8362f7 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 e5f14b13ccf0..08454880a2c0 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/ftrace.c b/arch/powerpc/kernel/ftrace.c
index f4b006ed0ab1..3271cd698e4c 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 +76,434 @@ 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)
+{
+ long diff;
+
+ /*
+ * Can we get to addr from ip in 24 bits?
+ * (26 really, since we mulitply by 4 for 4 byte alignment)
+ */
+ diff = addr - ip;
+
+ /*
+ * Return true if diff is less than 1 << 25
+ * and greater than -1 << 26.
+ */
+ return (diff < (1 << 25)) && (diff > (-1 << 26));
+}
+
+static int is_bl_op(unsigned int op)
+{
+ return (op & 0xfc000003) == 0x48000001;
+}
+
+static int test_offset(unsigned long offset)
+{
+ return (offset + 0x2000000 > 0x3ffffff) || ((offset & 3) != 0);
+}
+
+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;
+}
+
+static unsigned int branch_offset(unsigned long offset)
+{
+ /* return "bl ip+offset" */
+ return 0x48000001 | (offset & 0x03fffffc);
+}
+
+#ifdef CONFIG_PPC64
+static int
+__ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char replaced[MCOUNT_INSN_SIZE * 2];
+ unsigned int *op = (unsigned *)&replaced;
+ unsigned char jmp[8];
+ unsigned long *ptr = (unsigned long *)&jmp;
+ unsigned long ip = rec->ip;
+ unsigned long tramp;
+ int offset;
+
+ /* read where this goes */
+ if (probe_kernel_read(replaced, (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 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, 8)) {
+ printk(KERN_ERR "Failed to read %lx\n", tramp);
+ return -EFAULT;
+ }
+
+ DEBUGP(" %08x %08x",
+ (unsigned)(*ptr >> 32),
+ (unsigned)*ptr);
+
+ offset = (unsigned)jmp[2] << 24 |
+ (unsigned)jmp[3] << 16 |
+ (unsigned)jmp[6] << 8 |
+ (unsigned)jmp[7];
+
+ 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",
+ (unsigned)(*ptr >> 32),
+ (unsigned)*ptr);
+
+ /* 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(replaced, (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[0] = 0x48000008; /* b +8 */
+
+ if (probe_kernel_write((void *)ip, replaced, MCOUNT_INSN_SIZE))
+ return -EPERM;
+
+ return 0;
+}
+
+#else /* !PPC64 */
+static int
+__ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char replaced[MCOUNT_INSN_SIZE];
+ unsigned int *op = (unsigned *)&replaced;
+ unsigned char jmp[8];
+ unsigned int *ptr = (unsigned int *)&jmp;
+ unsigned long ip = rec->ip;
+ unsigned long tramp;
+ int offset;
+
+ if (probe_kernel_read(replaced, (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:
+ * lis r11,sym@ha
+ * addi r11,r11,sym@l
+ * mtctr r11
+ * bctr
+ */
+
+ DEBUGP("ip:%lx jumps to %lx", ip, tramp);
+
+ /* Find where the trampoline jumps to */
+ if (probe_kernel_read(jmp, (void *)tramp, 8)) {
+ printk(KERN_ERR "Failed to read %lx\n", tramp);
+ return -EFAULT;
+ }
+
+ DEBUGP(" %08x %08x ", ptr[0], ptr[1]);
+
+ tramp = (ptr[1] & 0xffff) |
+ ((ptr[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[0] = PPC_NOP_INSTR;
+
+ if (probe_kernel_write((void *)ip, replaced, MCOUNT_INSN_SIZE))
+ return -EPERM;
+
+ 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 char replaced[MCOUNT_INSN_SIZE * 2];
+ unsigned int *op = (unsigned *)&replaced;
+ unsigned long ip = rec->ip;
+ unsigned long offset;
+
+ /* read where this goes */
+ if (probe_kernel_read(replaced, (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;
+ }
+
+ /* now calculate a jump to the ftrace caller trampoline */
+ offset = rec->arch.mod->arch.tramp - ip;
+
+ if (test_offset(offset)) {
+ printk(KERN_ERR "REL24 %li out of range!\n",
+ (long int)offset);
+ return -EINVAL;
+ }
+
+ /* Set to "bl addr" */
+ op[0] = branch_offset(offset);
+ /* ld r2,40(r1) */
+ op[1] = 0xe8410028;
+
+ DEBUGP("write to %lx\n", rec->ip);
+
+ if (probe_kernel_write((void *)ip, replaced, MCOUNT_INSN_SIZE * 2))
+ return -EPERM;
+
+ return 0;
+}
+#else
+static int
+__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char replaced[MCOUNT_INSN_SIZE];
+ unsigned int *op = (unsigned *)&replaced;
+ unsigned long ip = rec->ip;
+ unsigned long offset;
+
+ /* read where this goes */
+ if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ /* It should be pointing to a nop */
+ if (op[0] != PPC_NOP_INSTR) {
+ printk(KERN_ERR "Expected NOP but have %x\n", op[0]);
+ 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;
+ }
+
+ /* now calculate a jump to the ftrace caller trampoline */
+ offset = rec->arch.mod->arch.tramp - ip;
+
+ if (test_offset(offset)) {
+ printk(KERN_ERR "REL24 %li out of range!\n",
+ (long int)offset);
+ return -EINVAL;
+ }
+
+ /* Set to "bl addr" */
+ op[0] = branch_offset(offset);
+
+ DEBUGP("write to %lx\n", rec->ip);
+
+ if (probe_kernel_write((void *)ip, replaced, MCOUNT_INSN_SIZE))
+ return -EPERM;
+
+ 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 +521,10 @@ 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 31982d05d81a..88d9c1d5e5fb 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 2df91a03462a..f832773fc28e 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 1af2377e4992..8992b031a7b6 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/x86/Kconfig b/arch/x86/Kconfig
index 7a146baaa990..e49a4fd718fe 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -36,6 +36,7 @@ config X86
select HAVE_ARCH_TRACEHOOK
select HAVE_GENERIC_DMA_COHERENT if X86_32
select HAVE_EFFICIENT_UNALIGNED_ACCESS
+ select USER_STACKTRACE_SUPPORT
config ARCH_DEFCONFIG
string
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 2bb43b433e07..754a3e082f94 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -29,7 +29,6 @@ struct dyn_arch_ftrace {
#endif /* CONFIG_FUNCTION_TRACER */
#ifdef CONFIG_FUNCTION_RET_TRACER
-#define FTRACE_RET_STACK_SIZE 20
#ifndef __ASSEMBLY__
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index e90e81ef6ab9..0921b4018c11 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -40,36 +40,8 @@ struct thread_info {
*/
__u8 supervisor_stack[0];
#endif
-
-#ifdef CONFIG_FUNCTION_RET_TRACER
- /* Index of current stored adress in ret_stack */
- int curr_ret_stack;
- /* Stack of return addresses for return function tracing */
- struct ftrace_ret_stack ret_stack[FTRACE_RET_STACK_SIZE];
- /*
- * Number of functions that haven't been traced
- * because of depth overrun.
- */
- atomic_t trace_overrun;
-#endif
};
-#ifdef CONFIG_FUNCTION_RET_TRACER
-#define INIT_THREAD_INFO(tsk) \
-{ \
- .task = &tsk, \
- .exec_domain = &default_exec_domain, \
- .flags = 0, \
- .cpu = 0, \
- .preempt_count = 1, \
- .addr_limit = KERNEL_DS, \
- .restart_block = { \
- .fn = do_no_restart_syscall, \
- }, \
- .curr_ret_stack = -1,\
- .trace_overrun = ATOMIC_INIT(0) \
-}
-#else
#define INIT_THREAD_INFO(tsk) \
{ \
.task = &tsk, \
@@ -82,7 +54,6 @@ struct thread_info {
.fn = do_no_restart_syscall, \
}, \
}
-#endif
#define init_thread_info (init_thread_union.thread_info)
#define init_stack (init_thread_union.stack)
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 356bb1eb6e9a..bb137f7297ed 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -350,19 +350,21 @@ static int push_return_trace(unsigned long ret, unsigned long long time,
unsigned long func)
{
int index;
- struct thread_info *ti = current_thread_info();
+
+ if (!current->ret_stack)
+ return -EBUSY;
/* The return trace stack is full */
- if (ti->curr_ret_stack == FTRACE_RET_STACK_SIZE - 1) {
- atomic_inc(&ti->trace_overrun);
+ if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
+ atomic_inc(&current->trace_overrun);
return -EBUSY;
}
- index = ++ti->curr_ret_stack;
+ index = ++current->curr_ret_stack;
barrier();
- ti->ret_stack[index].ret = ret;
- ti->ret_stack[index].func = func;
- ti->ret_stack[index].calltime = time;
+ current->ret_stack[index].ret = ret;
+ current->ret_stack[index].func = func;
+ current->ret_stack[index].calltime = time;
return 0;
}
@@ -373,13 +375,12 @@ static void pop_return_trace(unsigned long *ret, unsigned long long *time,
{
int index;
- struct thread_info *ti = current_thread_info();
- index = ti->curr_ret_stack;
- *ret = ti->ret_stack[index].ret;
- *func = ti->ret_stack[index].func;
- *time = ti->ret_stack[index].calltime;
- *overrun = atomic_read(&ti->trace_overrun);
- ti->curr_ret_stack--;
+ index = current->curr_ret_stack;
+ *ret = current->ret_stack[index].ret;
+ *func = current->ret_stack[index].func;
+ *time = current->ret_stack[index].calltime;
+ *overrun = atomic_read(&current->trace_overrun);
+ current->curr_ret_stack--;
}
/*
diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index a03e7f6d90c3..10786af95545 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -6,6 +6,7 @@
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <linux/module.h>
+#include <linux/uaccess.h>
#include <asm/stacktrace.h>
static void save_stack_warning(void *data, char *msg)
@@ -83,3 +84,66 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
+
+/* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */
+
+struct stack_frame {
+ const void __user *next_fp;
+ unsigned long ret_addr;
+};
+
+static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)
+{
+ int ret;
+
+ if (!access_ok(VERIFY_READ, fp, sizeof(*frame)))
+ return 0;
+
+ ret = 1;
+ pagefault_disable();
+ if (__copy_from_user_inatomic(frame, fp, sizeof(*frame)))
+ ret = 0;
+ pagefault_enable();
+
+ return ret;
+}
+
+static inline void __save_stack_trace_user(struct stack_trace *trace)
+{
+ const struct pt_regs *regs = task_pt_regs(current);
+ const void __user *fp = (const void __user *)regs->bp;
+
+ if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = regs->ip;
+
+ while (trace->nr_entries < trace->max_entries) {
+ struct stack_frame frame;
+
+ frame.next_fp = NULL;
+ frame.ret_addr = 0;
+ if (!copy_stack_frame(fp, &frame))
+ break;
+ if ((unsigned long)fp < regs->sp)
+ break;
+ if (frame.ret_addr) {
+ trace->entries[trace->nr_entries++] =
+ frame.ret_addr;
+ }
+ if (fp == frame.next_fp)
+ break;
+ fp = frame.next_fp;
+ }
+}
+
+void save_stack_trace_user(struct stack_trace *trace)
+{
+ /*
+ * Trace user stack if we are not a kernel thread
+ */
+ if (current->mm) {
+ __save_stack_trace_user(trace);
+ }
+ if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-14 18:45:46 +0000