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author | Ingo Molnar <mingo@elte.hu> | 2008-07-30 19:36:55 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-07-30 19:36:55 +0200 |
commit | bc588df79ebfb710abc27342fccf336a68ed1216 (patch) | |
tree | e50e125eaa6da83fa715704e53c1bde013d1ef8e /arch/sparc64/kernel/ftrace.c | |
parent | bce7f793daec3e65ec5c5705d2457b81fe7b5725 (diff) | |
parent | 15dd859cacf312f606f54502d1f66537a1e5c78c (diff) |
Merge branch 'x86/core' into x86/xsave
Diffstat (limited to 'arch/sparc64/kernel/ftrace.c')
-rw-r--r-- | arch/sparc64/kernel/ftrace.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/arch/sparc64/kernel/ftrace.c b/arch/sparc64/kernel/ftrace.c new file mode 100644 index 00000000000..4298d0aee71 --- /dev/null +++ b/arch/sparc64/kernel/ftrace.c @@ -0,0 +1,94 @@ +#include <linux/spinlock.h> +#include <linux/hardirq.h> +#include <linux/ftrace.h> +#include <linux/percpu.h> +#include <linux/init.h> +#include <linux/list.h> + +#include <asm/ftrace.h> + +static const u32 ftrace_nop = 0x01000000; + +notrace unsigned char *ftrace_nop_replace(void) +{ + return (char *)&ftrace_nop; +} + +notrace unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr) +{ + static u32 call; + s32 off; + + off = ((s32)addr - (s32)ip); + call = 0x40000000 | ((u32)off >> 2); + + return (unsigned char *) &call; +} + +notrace int +ftrace_modify_code(unsigned long ip, unsigned char *old_code, + unsigned char *new_code) +{ + u32 old = *(u32 *)old_code; + u32 new = *(u32 *)new_code; + u32 replaced; + int faulted; + + __asm__ __volatile__( + "1: cas [%[ip]], %[old], %[new]\n" + " flush %[ip]\n" + " mov 0, %[faulted]\n" + "2:\n" + " .section .fixup,#alloc,#execinstr\n" + " .align 4\n" + "3: sethi %%hi(2b), %[faulted]\n" + " jmpl %[faulted] + %%lo(2b), %%g0\n" + " mov 1, %[faulted]\n" + " .previous\n" + " .section __ex_table,\"a\"\n" + " .align 4\n" + " .word 1b, 3b\n" + " .previous\n" + : "=r" (replaced), [faulted] "=r" (faulted) + : [new] "0" (new), [old] "r" (old), [ip] "r" (ip) + : "memory"); + + if (replaced != old && replaced != new) + faulted = 2; + + return faulted; +} + +notrace int ftrace_update_ftrace_func(ftrace_func_t func) +{ + unsigned long ip = (unsigned long)(&ftrace_call); + unsigned char old[MCOUNT_INSN_SIZE], *new; + + memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE); + new = ftrace_call_replace(ip, (unsigned long)func); + return ftrace_modify_code(ip, old, new); +} + +notrace int ftrace_mcount_set(unsigned long *data) +{ + unsigned long ip = (long)(&mcount_call); + unsigned long *addr = data; + unsigned char old[MCOUNT_INSN_SIZE], *new; + + /* + * Replace the mcount stub with a pointer to the + * ip recorder function. + */ + memcpy(old, &mcount_call, MCOUNT_INSN_SIZE); + new = ftrace_call_replace(ip, *addr); + *addr = ftrace_modify_code(ip, old, new); + + return 0; +} + + +int __init ftrace_dyn_arch_init(void *data) +{ + ftrace_mcount_set(data); + return 0; +} |