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-rw-r--r--arch/mips/kernel/ftrace.c184
-rw-r--r--arch/mips/kernel/mcount.S55
-rw-r--r--arch/mips/kernel/mips-mt-fpaff.c87
-rw-r--r--arch/mips/kernel/traps.c2
4 files changed, 208 insertions, 120 deletions
diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c
index e9e64e0..5a84a1f 100644
--- a/arch/mips/kernel/ftrace.c
+++ b/arch/mips/kernel/ftrace.c
@@ -2,7 +2,7 @@
* Code for replacing ftrace calls with jumps.
*
* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
- * Copyright (C) 2009 DSLab, Lanzhou University, China
+ * Copyright (C) 2009, 2010 DSLab, Lanzhou University, China
* Author: Wu Zhangjin <wuzhangjin@gmail.com>
*
* Thanks goes to Steven Rostedt for writing the original x86 version.
@@ -12,18 +12,62 @@
#include <linux/init.h>
#include <linux/ftrace.h>
-#include <asm/cacheflush.h>
#include <asm/asm.h>
#include <asm/asm-offsets.h>
+#include <asm/cacheflush.h>
+#include <asm/uasm.h>
+
+/*
+ * If the Instruction Pointer is in module space (0xc0000000), return true;
+ * otherwise, it is in kernel space (0x80000000), return false.
+ *
+ * FIXME: This will not work when the kernel space and module space are the
+ * same. If they are the same, we need to modify scripts/recordmcount.pl,
+ * ftrace_make_nop/call() and the other related parts to ensure the
+ * enabling/disabling of the calling site to _mcount is right for both kernel
+ * and module.
+ */
+
+static inline int in_module(unsigned long ip)
+{
+ return ip & 0x40000000;
+}
#ifdef CONFIG_DYNAMIC_FTRACE
#define JAL 0x0c000000 /* jump & link: ip --> ra, jump to target */
#define ADDR_MASK 0x03ffffff /* op_code|addr : 31...26|25 ....0 */
-#define jump_insn_encode(op_code, addr) \
- ((unsigned int)((op_code) | (((addr) >> 2) & ADDR_MASK)))
-static unsigned int ftrace_nop = 0x00000000;
+#define INSN_B_1F_4 0x10000004 /* b 1f; offset = 4 */
+#define INSN_B_1F_5 0x10000005 /* b 1f; offset = 5 */
+#define INSN_NOP 0x00000000 /* nop */
+#define INSN_JAL(addr) \
+ ((unsigned int)(JAL | (((addr) >> 2) & ADDR_MASK)))
+
+static unsigned int insn_jal_ftrace_caller __read_mostly;
+static unsigned int insn_lui_v1_hi16_mcount __read_mostly;
+static unsigned int insn_j_ftrace_graph_caller __maybe_unused __read_mostly;
+
+static inline void ftrace_dyn_arch_init_insns(void)
+{
+ u32 *buf;
+ unsigned int v1;
+
+ /* lui v1, hi16_mcount */
+ v1 = 3;
+ buf = (u32 *)&insn_lui_v1_hi16_mcount;
+ UASM_i_LA_mostly(&buf, v1, MCOUNT_ADDR);
+
+ /* jal (ftrace_caller + 8), jump over the first two instruction */
+ buf = (u32 *)&insn_jal_ftrace_caller;
+ uasm_i_jal(&buf, (FTRACE_ADDR + 8));
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ /* j ftrace_graph_caller */
+ buf = (u32 *)&insn_j_ftrace_graph_caller;
+ uasm_i_j(&buf, (unsigned long)ftrace_graph_caller);
+#endif
+}
static int ftrace_modify_code(unsigned long ip, unsigned int new_code)
{
@@ -40,67 +84,56 @@ static int ftrace_modify_code(unsigned long ip, unsigned int new_code)
return 0;
}
-static int lui_v1;
-static int jal_mcount;
-
int ftrace_make_nop(struct module *mod,
struct dyn_ftrace *rec, unsigned long addr)
{
unsigned int new;
- int faulted;
unsigned long ip = rec->ip;
- /* We have compiled module with -mlong-calls, but compiled the kernel
- * without it, we need to cope with them respectively. */
- if (ip & 0x40000000) {
- /* record it for ftrace_make_call */
- if (lui_v1 == 0) {
- /* lui_v1 = *(unsigned int *)ip; */
- safe_load_code(lui_v1, ip, faulted);
-
- if (unlikely(faulted))
- return -EFAULT;
- }
-
- /* lui v1, hi_16bit_of_mcount --> b 1f (0x10000004)
+ /*
+ * We have compiled module with -mlong-calls, but compiled the kernel
+ * without it, we need to cope with them respectively.
+ */
+ if (in_module(ip)) {
+#if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT)
+ /*
+ * lui v1, hi_16bit_of_mcount --> b 1f (0x10000005)
+ * addiu v1, v1, low_16bit_of_mcount
+ * move at, ra
+ * move $12, ra_address
+ * jalr v1
+ * sub sp, sp, 8
+ * 1: offset = 5 instructions
+ */
+ new = INSN_B_1F_5;
+#else
+ /*
+ * lui v1, hi_16bit_of_mcount --> b 1f (0x10000004)
* addiu v1, v1, low_16bit_of_mcount
* move at, ra
* jalr v1
- * nop
- * 1f: (ip + 12)
+ * nop | move $12, ra_address | sub sp, sp, 8
+ * 1: offset = 4 instructions
*/
- new = 0x10000004;
+ new = INSN_B_1F_4;
+#endif
} else {
- /* record/calculate it for ftrace_make_call */
- if (jal_mcount == 0) {
- /* We can record it directly like this:
- * jal_mcount = *(unsigned int *)ip;
- * Herein, jump over the first two nop instructions */
- jal_mcount = jump_insn_encode(JAL, (MCOUNT_ADDR + 8));
- }
-
- /* move at, ra
- * jalr v1 --> nop
+ /*
+ * move at, ra
+ * jal _mcount --> nop
*/
- new = ftrace_nop;
+ new = INSN_NOP;
}
return ftrace_modify_code(ip, new);
}
-static int modified; /* initialized as 0 by default */
-
int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
{
unsigned int new;
unsigned long ip = rec->ip;
- /* We just need to remove the "b ftrace_stub" at the fist time! */
- if (modified == 0) {
- modified = 1;
- ftrace_modify_code(addr, ftrace_nop);
- }
/* ip, module: 0xc0000000, kernel: 0x80000000 */
- new = (ip & 0x40000000) ? lui_v1 : jal_mcount;
+ new = in_module(ip) ? insn_lui_v1_hi16_mcount : insn_jal_ftrace_caller;
return ftrace_modify_code(ip, new);
}
@@ -111,44 +144,48 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
{
unsigned int new;
- new = jump_insn_encode(JAL, (unsigned long)func);
+ new = INSN_JAL((unsigned long)func);
return ftrace_modify_code(FTRACE_CALL_IP, new);
}
int __init ftrace_dyn_arch_init(void *data)
{
+ /* Encode the instructions when booting */
+ ftrace_dyn_arch_init_insns();
+
+ /* Remove "b ftrace_stub" to ensure ftrace_caller() is executed */
+ ftrace_modify_code(MCOUNT_ADDR, INSN_NOP);
+
/* The return code is retured via data */
*(unsigned long *)data = 0;
return 0;
}
-#endif /* CONFIG_DYNAMIC_FTRACE */
+#endif /* CONFIG_DYNAMIC_FTRACE */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
#ifdef CONFIG_DYNAMIC_FTRACE
extern void ftrace_graph_call(void);
-#define JMP 0x08000000 /* jump to target directly */
-#define CALL_FTRACE_GRAPH_CALLER \
- jump_insn_encode(JMP, (unsigned long)(&ftrace_graph_caller))
#define FTRACE_GRAPH_CALL_IP ((unsigned long)(&ftrace_graph_call))
int ftrace_enable_ftrace_graph_caller(void)
{
return ftrace_modify_code(FTRACE_GRAPH_CALL_IP,
- CALL_FTRACE_GRAPH_CALLER);
+ insn_j_ftrace_graph_caller);
}
int ftrace_disable_ftrace_graph_caller(void)
{
- return ftrace_modify_code(FTRACE_GRAPH_CALL_IP, ftrace_nop);
+ return ftrace_modify_code(FTRACE_GRAPH_CALL_IP, INSN_NOP);
}
-#endif /* !CONFIG_DYNAMIC_FTRACE */
+#endif /* CONFIG_DYNAMIC_FTRACE */
#ifndef KBUILD_MCOUNT_RA_ADDRESS
+
#define S_RA_SP (0xafbf << 16) /* s{d,w} ra, offset(sp) */
#define S_R_SP (0xafb0 << 16) /* s{d,w} R, offset(sp) */
#define OFFSET_MASK 0xffff /* stack offset range: 0 ~ PT_SIZE */
@@ -162,17 +199,17 @@ unsigned long ftrace_get_parent_addr(unsigned long self_addr,
unsigned int code;
int faulted;
- /* in module or kernel? */
- if (self_addr & 0x40000000) {
- /* module: move to the instruction "lui v1, HI_16BIT_OF_MCOUNT" */
- ip = self_addr - 20;
- } else {
- /* kernel: move to the instruction "move ra, at" */
- ip = self_addr - 12;
- }
+ /*
+ * For module, move the ip from calling site of mcount to the
+ * instruction "lui v1, hi_16bit_of_mcount"(offset is 20), but for
+ * kernel, move to the instruction "move ra, at"(offset is 12)
+ */
+ ip = self_addr - (in_module(self_addr) ? 20 : 12);
- /* search the text until finding the non-store instruction or "s{d,w}
- * ra, offset(sp)" instruction */
+ /*
+ * search the text until finding the non-store instruction or "s{d,w}
+ * ra, offset(sp)" instruction
+ */
do {
ip -= 4;
@@ -181,10 +218,11 @@ unsigned long ftrace_get_parent_addr(unsigned long self_addr,
if (unlikely(faulted))
return 0;
-
- /* If we hit the non-store instruction before finding where the
+ /*
+ * If we hit the non-store instruction before finding where the
* ra is stored, then this is a leaf function and it does not
- * store the ra on the stack. */
+ * store the ra on the stack
+ */
if ((code & S_R_SP) != S_R_SP)
return parent_addr;
@@ -202,7 +240,7 @@ unsigned long ftrace_get_parent_addr(unsigned long self_addr,
return 0;
}
-#endif
+#endif /* !KBUILD_MCOUNT_RA_ADDRESS */
/*
* Hook the return address and push it in the stack of return addrs
@@ -220,7 +258,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
if (unlikely(atomic_read(&current->tracing_graph_pause)))
return;
- /* "parent" is the stack address saved the return address of the caller
+ /*
+ * "parent" is the stack address saved the return address of the caller
* of _mcount.
*
* if the gcc < 4.5, a leaf function does not save the return address
@@ -242,10 +281,11 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
goto out;
#ifndef KBUILD_MCOUNT_RA_ADDRESS
parent = (unsigned long *)ftrace_get_parent_addr(self_addr, old,
- (unsigned long)parent,
- fp);
- /* If fails when getting the stack address of the non-leaf function's
- * ra, stop function graph tracer and return */
+ (unsigned long)parent, fp);
+ /*
+ * If fails when getting the stack address of the non-leaf function's
+ * ra, stop function graph tracer and return
+ */
if (parent == 0)
goto out;
#endif
@@ -272,4 +312,4 @@ out:
ftrace_graph_stop();
WARN_ON(1);
}
-#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S
index 6851fc9..6bfcb7a 100644
--- a/arch/mips/kernel/mcount.S
+++ b/arch/mips/kernel/mcount.S
@@ -6,6 +6,7 @@
* more details.
*
* Copyright (C) 2009 Lemote Inc. & DSLab, Lanzhou University, China
+ * Copyright (C) 2010 DSLab, Lanzhou University, China
* Author: Wu Zhangjin <wuzhangjin@gmail.com>
*/
@@ -45,8 +46,6 @@
PTR_L a5, PT_R9(sp)
PTR_L a6, PT_R10(sp)
PTR_L a7, PT_R11(sp)
-#endif
-#ifdef CONFIG_64BIT
PTR_ADDIU sp, PT_SIZE
#else
PTR_ADDIU sp, (PT_SIZE + 8)
@@ -58,6 +57,12 @@
move ra, AT
.endm
+/*
+ * The -mmcount-ra-address option of gcc 4.5 uses register $12 to pass
+ * the location of the parent's return address.
+ */
+#define MCOUNT_RA_ADDRESS_REG $12
+
#ifdef CONFIG_DYNAMIC_FTRACE
NESTED(ftrace_caller, PT_SIZE, ra)
@@ -71,14 +76,14 @@ _mcount:
MCOUNT_SAVE_REGS
#ifdef KBUILD_MCOUNT_RA_ADDRESS
- PTR_S t0, PT_R12(sp) /* t0 saved the location of the return address(at) by -mmcount-ra-address */
+ PTR_S MCOUNT_RA_ADDRESS_REG, PT_R12(sp)
#endif
- move a0, ra /* arg1: next ip, selfaddr */
+ move a0, ra /* arg1: self return address */
.globl ftrace_call
ftrace_call:
nop /* a placeholder for the call to a real tracing function */
- move a1, AT /* arg2: the caller's next ip, parent */
+ move a1, AT /* arg2: parent's return address */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
.globl ftrace_graph_call
@@ -119,9 +124,9 @@ NESTED(_mcount, PT_SIZE, ra)
static_trace:
MCOUNT_SAVE_REGS
- move a0, ra /* arg1: next ip, selfaddr */
+ move a0, ra /* arg1: self return address */
jalr t2 /* (1) call *ftrace_trace_function */
- move a1, AT /* arg2: the caller's next ip, parent */
+ move a1, AT /* arg2: parent's return address */
MCOUNT_RESTORE_REGS
.globl ftrace_stub
@@ -134,28 +139,34 @@ ftrace_stub:
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
NESTED(ftrace_graph_caller, PT_SIZE, ra)
-#ifdef CONFIG_DYNAMIC_FTRACE
- PTR_L a1, PT_R31(sp) /* load the original ra from the stack */
-#ifdef KBUILD_MCOUNT_RA_ADDRESS
- PTR_L t0, PT_R12(sp) /* load the original t0 from the stack */
-#endif
-#else
+#ifndef CONFIG_DYNAMIC_FTRACE
MCOUNT_SAVE_REGS
- move a1, ra /* arg2: next ip, selfaddr */
#endif
+ /* arg1: Get the location of the parent's return address */
#ifdef KBUILD_MCOUNT_RA_ADDRESS
- bnez t0, 1f /* non-leaf func: t0 saved the location of the return address */
+#ifdef CONFIG_DYNAMIC_FTRACE
+ PTR_L a0, PT_R12(sp)
+#else
+ move a0, MCOUNT_RA_ADDRESS_REG
+#endif
+ bnez a0, 1f /* non-leaf func: stored in MCOUNT_RA_ADDRESS_REG */
nop
- PTR_LA t0, PT_R1(sp) /* leaf func: get the location of at(old ra) from our own stack */
-1: move a0, t0 /* arg1: the location of the return address */
+#endif
+ PTR_LA a0, PT_R1(sp) /* leaf func: the location in current stack */
+1:
+
+ /* arg2: Get self return address */
+#ifdef CONFIG_DYNAMIC_FTRACE
+ PTR_L a1, PT_R31(sp)
#else
- PTR_LA a0, PT_R1(sp) /* arg1: &AT -> a0 */
+ move a1, ra
#endif
- jal prepare_ftrace_return
+
+ /* arg3: Get frame pointer of current stack */
#ifdef CONFIG_FRAME_POINTER
- move a2, fp /* arg3: frame pointer */
-#else
+ move a2, fp
+#else /* ! CONFIG_FRAME_POINTER */
#ifdef CONFIG_64BIT
PTR_LA a2, PT_SIZE(sp)
#else
@@ -163,6 +174,8 @@ NESTED(ftrace_graph_caller, PT_SIZE, ra)
#endif
#endif
+ jal prepare_ftrace_return
+ nop
MCOUNT_RESTORE_REGS
RETURN_BACK
END(ftrace_graph_caller)
diff --git a/arch/mips/kernel/mips-mt-fpaff.c b/arch/mips/kernel/mips-mt-fpaff.c
index f5981c4..2340f11 100644
--- a/arch/mips/kernel/mips-mt-fpaff.c
+++ b/arch/mips/kernel/mips-mt-fpaff.c
@@ -3,6 +3,7 @@
* Copyright (C) 2005 Mips Technologies, Inc
*/
#include <linux/cpu.h>
+#include <linux/cpuset.h>
#include <linux/cpumask.h>
#include <linux/delay.h>
#include <linux/kernel.h>
@@ -39,6 +40,21 @@ static inline struct task_struct *find_process_by_pid(pid_t pid)
return pid ? find_task_by_vpid(pid) : current;
}
+/*
+ * check the target process has a UID that matches the current process's
+ */
+static bool check_same_owner(struct task_struct *p)
+{
+ const struct cred *cred = current_cred(), *pcred;
+ bool match;
+
+ rcu_read_lock();
+ pcred = __task_cred(p);
+ match = (cred->euid == pcred->euid ||
+ cred->euid == pcred->uid);
+ rcu_read_unlock();
+ return match;
+}
/*
* mipsmt_sys_sched_setaffinity - set the cpu affinity of a process
@@ -46,12 +62,10 @@ static inline struct task_struct *find_process_by_pid(pid_t pid)
asmlinkage long mipsmt_sys_sched_setaffinity(pid_t pid, unsigned int len,
unsigned long __user *user_mask_ptr)
{
- cpumask_t new_mask;
- cpumask_t effective_mask;
- int retval;
- struct task_struct *p;
+ cpumask_var_t cpus_allowed, new_mask, effective_mask;
struct thread_info *ti;
- uid_t euid;
+ struct task_struct *p;
+ int retval;
if (len < sizeof(new_mask))
return -EINVAL;
@@ -60,53 +74,74 @@ asmlinkage long mipsmt_sys_sched_setaffinity(pid_t pid, unsigned int len,
return -EFAULT;
get_online_cpus();
- read_lock(&tasklist_lock);
+ rcu_read_lock();
p = find_process_by_pid(pid);
if (!p) {
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
put_online_cpus();
return -ESRCH;
}
- /*
- * It is not safe to call set_cpus_allowed with the
- * tasklist_lock held. We will bump the task_struct's
- * usage count and drop tasklist_lock before invoking
- * set_cpus_allowed.
- */
+ /* Prevent p going away */
get_task_struct(p);
+ rcu_read_unlock();
- euid = current_euid();
+ if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
+ retval = -ENOMEM;
+ goto out_put_task;
+ }
+ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
+ retval = -ENOMEM;
+ goto out_free_cpus_allowed;
+ }
+ if (!alloc_cpumask_var(&effective_mask, GFP_KERNEL)) {
+ retval = -ENOMEM;
+ goto out_free_new_mask;
+ }
retval = -EPERM;
- if (euid != p->cred->euid && euid != p->cred->uid &&
- !capable(CAP_SYS_NICE)) {
- read_unlock(&tasklist_lock);
+ if (!check_same_owner(p) && !capable(CAP_SYS_NICE))
goto out_unlock;
- }
retval = security_task_setscheduler(p, 0, NULL);
if (retval)
goto out_unlock;
/* Record new user-specified CPU set for future reference */
- p->thread.user_cpus_allowed = new_mask;
-
- /* Unlock the task list */
- read_unlock(&tasklist_lock);
+ cpumask_copy(&p->thread.user_cpus_allowed, new_mask);
+ again:
/* Compute new global allowed CPU set if necessary */
ti = task_thread_info(p);
if (test_ti_thread_flag(ti, TIF_FPUBOUND) &&
- cpus_intersects(new_mask, mt_fpu_cpumask)) {
- cpus_and(effective_mask, new_mask, mt_fpu_cpumask);
- retval = set_cpus_allowed_ptr(p, &effective_mask);
+ cpus_intersects(*new_mask, mt_fpu_cpumask)) {
+ cpus_and(*effective_mask, *new_mask, mt_fpu_cpumask);
+ retval = set_cpus_allowed_ptr(p, effective_mask);
} else {
+ cpumask_copy(effective_mask, new_mask);
clear_ti_thread_flag(ti, TIF_FPUBOUND);
- retval = set_cpus_allowed_ptr(p, &new_mask);
+ retval = set_cpus_allowed_ptr(p, new_mask);
}
+ if (!retval) {
+ cpuset_cpus_allowed(p, cpus_allowed);
+ if (!cpumask_subset(effective_mask, cpus_allowed)) {
+ /*
+ * We must have raced with a concurrent cpuset
+ * update. Just reset the cpus_allowed to the
+ * cpuset's cpus_allowed
+ */
+ cpumask_copy(new_mask, cpus_allowed);
+ goto again;
+ }
+ }
out_unlock:
+ free_cpumask_var(effective_mask);
+out_free_new_mask:
+ free_cpumask_var(new_mask);
+out_free_cpus_allowed:
+ free_cpumask_var(cpus_allowed);
+out_put_task:
put_task_struct(p);
put_online_cpus();
return retval;
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 8bdd6a6..8527808 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -976,7 +976,7 @@ asmlinkage void do_cpu(struct pt_regs *regs)
case 2:
raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
- break;
+ return;
case 3:
break;
generated by cgit v0.10.2 at 2024-08-01 13:38:13 (GMT)