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authorDavid S. Miller <davem@davemloft.net>2010-08-16 14:09:34 -0700
committerDavid S. Miller <davem@davemloft.net>2010-08-16 14:09:34 -0700
commit300a103d1504134f8c4a7e831f995e917ea9b1e4 (patch)
tree7f94d5fff513d132bd0b57a9e3bd96c4cc80d707 /arch/arm/kernel
parent0a492896ac07336c98f37ad7fab4a6387b6ada78 (diff)
parentda5cabf80e2433131bf0ed8993abc0f7ea618c73 (diff)
downloadop-kernel-dev-300a103d1504134f8c4a7e831f995e917ea9b1e4.zip
op-kernel-dev-300a103d1504134f8c4a7e831f995e917ea9b1e4.tar.gz
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/entry-common.S124
-rw-r--r--arch/arm/kernel/etm.c4
-rw-r--r--arch/arm/kernel/module.c34
-rw-r--r--arch/arm/kernel/sys_arm.c4
-rw-r--r--arch/arm/kernel/sys_oabi-compat.c6
5 files changed, 122 insertions, 50 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 2c1db77..f05a35a 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -92,75 +92,111 @@ ENDPROC(ret_from_fork)
#define CALL(x) .long x
#ifdef CONFIG_FUNCTION_TRACER
+/*
+ * When compiling with -pg, gcc inserts a call to the mcount routine at the
+ * start of every function. In mcount, apart from the function's address (in
+ * lr), we need to get hold of the function's caller's address.
+ *
+ * Older GCCs (pre-4.4) inserted a call to a routine called mcount like this:
+ *
+ * bl mcount
+ *
+ * These versions have the limitation that in order for the mcount routine to
+ * be able to determine the function's caller's address, an APCS-style frame
+ * pointer (which is set up with something like the code below) is required.
+ *
+ * mov ip, sp
+ * push {fp, ip, lr, pc}
+ * sub fp, ip, #4
+ *
+ * With EABI, these frame pointers are not available unless -mapcs-frame is
+ * specified, and if building as Thumb-2, not even then.
+ *
+ * Newer GCCs (4.4+) solve this problem by introducing a new version of mcount,
+ * with call sites like:
+ *
+ * push {lr}
+ * bl __gnu_mcount_nc
+ *
+ * With these compilers, frame pointers are not necessary.
+ *
+ * mcount can be thought of as a function called in the middle of a subroutine
+ * call. As such, it needs to be transparent for both the caller and the
+ * callee: the original lr needs to be restored when leaving mcount, and no
+ * registers should be clobbered. (In the __gnu_mcount_nc implementation, we
+ * clobber the ip register. This is OK because the ARM calling convention
+ * allows it to be clobbered in subroutines and doesn't use it to hold
+ * parameters.)
+ */
#ifdef CONFIG_DYNAMIC_FTRACE
ENTRY(mcount)
- stmdb sp!, {r0-r3, lr}
- mov r0, lr
- sub r0, r0, #MCOUNT_INSN_SIZE
+ stmdb sp!, {r0-r3, lr}
+ mov r0, lr
+ sub r0, r0, #MCOUNT_INSN_SIZE
.globl mcount_call
mcount_call:
- bl ftrace_stub
- ldr lr, [fp, #-4] @ restore lr
- ldmia sp!, {r0-r3, pc}
+ bl ftrace_stub
+ ldr lr, [fp, #-4] @ restore lr
+ ldmia sp!, {r0-r3, pc}
ENTRY(ftrace_caller)
- stmdb sp!, {r0-r3, lr}
- ldr r1, [fp, #-4]
- mov r0, lr
- sub r0, r0, #MCOUNT_INSN_SIZE
+ stmdb sp!, {r0-r3, lr}
+ ldr r1, [fp, #-4]
+ mov r0, lr
+ sub r0, r0, #MCOUNT_INSN_SIZE
.globl ftrace_call
ftrace_call:
- bl ftrace_stub
- ldr lr, [fp, #-4] @ restore lr
- ldmia sp!, {r0-r3, pc}
+ bl ftrace_stub
+ ldr lr, [fp, #-4] @ restore lr
+ ldmia sp!, {r0-r3, pc}
#else
ENTRY(__gnu_mcount_nc)
- stmdb sp!, {r0-r3, lr}
- ldr r0, =ftrace_trace_function
- ldr r2, [r0]
- adr r0, ftrace_stub
- cmp r0, r2
- bne gnu_trace
- ldmia sp!, {r0-r3, ip, lr}
- mov pc, ip
+ stmdb sp!, {r0-r3, lr}
+ ldr r0, =ftrace_trace_function
+ ldr r2, [r0]
+ adr r0, ftrace_stub
+ cmp r0, r2
+ bne gnu_trace
+ ldmia sp!, {r0-r3, ip, lr}
+ mov pc, ip
gnu_trace:
- ldr r1, [sp, #20] @ lr of instrumented routine
- mov r0, lr
- sub r0, r0, #MCOUNT_INSN_SIZE
- mov lr, pc
- mov pc, r2
- ldmia sp!, {r0-r3, ip, lr}
- mov pc, ip
+ ldr r1, [sp, #20] @ lr of instrumented routine
+ mov r0, lr
+ sub r0, r0, #MCOUNT_INSN_SIZE
+ mov lr, pc
+ mov pc, r2
+ ldmia sp!, {r0-r3, ip, lr}
+ mov pc, ip
ENTRY(mcount)
- stmdb sp!, {r0-r3, lr}
- ldr r0, =ftrace_trace_function
- ldr r2, [r0]
- adr r0, ftrace_stub
- cmp r0, r2
- bne trace
- ldr lr, [fp, #-4] @ restore lr
- ldmia sp!, {r0-r3, pc}
+ stmdb sp!, {r0-r3, lr}
+ ldr r0, =ftrace_trace_function
+ ldr r2, [r0]
+ adr r0, ftrace_stub
+ cmp r0, r2
+ bne trace
+ ldr lr, [fp, #-4] @ restore lr
+ ldmia sp!, {r0-r3, pc}
trace:
- ldr r1, [fp, #-4] @ lr of instrumented routine
- mov r0, lr
- sub r0, r0, #MCOUNT_INSN_SIZE
- mov lr, pc
- mov pc, r2
- ldr lr, [fp, #-4] @ restore lr
- ldmia sp!, {r0-r3, pc}
+ ldr r1, [fp, #-4] @ lr of instrumented routine
+ mov r0, lr
+ sub r0, r0, #MCOUNT_INSN_SIZE
+ mov lr, pc
+ mov pc, r2
+ ldr lr, [fp, #-4] @ restore lr
+ ldmia sp!, {r0-r3, pc}
#endif /* CONFIG_DYNAMIC_FTRACE */
.globl ftrace_stub
ftrace_stub:
- mov pc, lr
+ mov pc, lr
#endif /* CONFIG_FUNCTION_TRACER */
diff --git a/arch/arm/kernel/etm.c b/arch/arm/kernel/etm.c
index 8277539..56418f9 100644
--- a/arch/arm/kernel/etm.c
+++ b/arch/arm/kernel/etm.c
@@ -543,7 +543,9 @@ static int __init etm_probe(struct amba_device *dev, struct amba_id *id)
t->etm_portsz = 1;
etm_unlock(t);
- ret = etm_readl(t, CSCR_PRSR);
+ (void)etm_readl(t, ETMMR_PDSR);
+ /* dummy first read */
+ (void)etm_readl(&tracer, ETMMR_OSSRR);
t->ncmppairs = etm_readl(t, ETMR_CONFCODE) & 0xf;
etm_writel(t, 0x440, ETMR_CTRL);
diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c
index c628bdf..6b46058 100644
--- a/arch/arm/kernel/module.c
+++ b/arch/arm/kernel/module.c
@@ -102,7 +102,9 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
unsigned long loc;
Elf32_Sym *sym;
s32 offset;
+#ifdef CONFIG_THUMB2_KERNEL
u32 upper, lower, sign, j1, j2;
+#endif
offset = ELF32_R_SYM(rel->r_info);
if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
@@ -185,6 +187,7 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
(offset & 0x0fff);
break;
+#ifdef CONFIG_THUMB2_KERNEL
case R_ARM_THM_CALL:
case R_ARM_THM_JUMP24:
upper = *(u16 *)loc;
@@ -233,9 +236,40 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
*(u16 *)(loc + 2) = (u16)((lower & 0xd000) |
(j1 << 13) | (j2 << 11) |
((offset >> 1) & 0x07ff));
+ break;
+
+ case R_ARM_THM_MOVW_ABS_NC:
+ case R_ARM_THM_MOVT_ABS:
upper = *(u16 *)loc;
lower = *(u16 *)(loc + 2);
+
+ /*
+ * MOVT/MOVW instructions encoding in Thumb-2:
+ *
+ * i = upper[10]
+ * imm4 = upper[3:0]
+ * imm3 = lower[14:12]
+ * imm8 = lower[7:0]
+ *
+ * imm16 = imm4:i:imm3:imm8
+ */
+ offset = ((upper & 0x000f) << 12) |
+ ((upper & 0x0400) << 1) |
+ ((lower & 0x7000) >> 4) | (lower & 0x00ff);
+ offset = (offset ^ 0x8000) - 0x8000;
+ offset += sym->st_value;
+
+ if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS)
+ offset >>= 16;
+
+ *(u16 *)loc = (u16)((upper & 0xfbf0) |
+ ((offset & 0xf000) >> 12) |
+ ((offset & 0x0800) >> 1));
+ *(u16 *)(loc + 2) = (u16)((lower & 0x8f00) |
+ ((offset & 0x0700) << 4) |
+ (offset & 0x00ff));
break;
+#endif
default:
printk(KERN_ERR "%s: unknown relocation: %u\n",
diff --git a/arch/arm/kernel/sys_arm.c b/arch/arm/kernel/sys_arm.c
index c235018..5b7c541 100644
--- a/arch/arm/kernel/sys_arm.c
+++ b/arch/arm/kernel/sys_arm.c
@@ -62,7 +62,7 @@ asmlinkage int sys_vfork(struct pt_regs *regs)
/* sys_execve() executes a new program.
* This is called indirectly via a small wrapper
*/
-asmlinkage int sys_execve(char __user *filenamei, char __user * __user *argv,
+asmlinkage int sys_execve(const char __user *filenamei, char __user * __user *argv,
char __user * __user *envp, struct pt_regs *regs)
{
int error;
@@ -84,7 +84,7 @@ int kernel_execve(const char *filename, char *const argv[], char *const envp[])
int ret;
memset(&regs, 0, sizeof(struct pt_regs));
- ret = do_execve((char *)filename, (char __user * __user *)argv,
+ ret = do_execve(filename, (char __user * __user *)argv,
(char __user * __user *)envp, &regs);
if (ret < 0)
goto out;
diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c
index 33ff678..4ad8da1 100644
--- a/arch/arm/kernel/sys_oabi-compat.c
+++ b/arch/arm/kernel/sys_oabi-compat.c
@@ -141,7 +141,7 @@ static long cp_oldabi_stat64(struct kstat *stat,
return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}
-asmlinkage long sys_oabi_stat64(char __user * filename,
+asmlinkage long sys_oabi_stat64(const char __user * filename,
struct oldabi_stat64 __user * statbuf)
{
struct kstat stat;
@@ -151,7 +151,7 @@ asmlinkage long sys_oabi_stat64(char __user * filename,
return error;
}
-asmlinkage long sys_oabi_lstat64(char __user * filename,
+asmlinkage long sys_oabi_lstat64(const char __user * filename,
struct oldabi_stat64 __user * statbuf)
{
struct kstat stat;
@@ -172,7 +172,7 @@ asmlinkage long sys_oabi_fstat64(unsigned long fd,
}
asmlinkage long sys_oabi_fstatat64(int dfd,
- char __user *filename,
+ const char __user *filename,
struct oldabi_stat64 __user *statbuf,
int flag)
{
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