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138 lines
3.0 KiB
138 lines
3.0 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#include <linux/spinlock.h> |
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#include <linux/hardirq.h> |
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#include <linux/ftrace.h> |
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#include <linux/percpu.h> |
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#include <linux/init.h> |
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#include <linux/list.h> |
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#include <trace/syscall.h> |
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#include <asm/ftrace.h> |
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#ifdef CONFIG_DYNAMIC_FTRACE |
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static const u32 ftrace_nop = 0x01000000; |
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static u32 ftrace_call_replace(unsigned long ip, unsigned long addr) |
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{ |
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u32 call; |
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s32 off; |
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off = ((s32)addr - (s32)ip); |
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call = 0x40000000 | ((u32)off >> 2); |
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return call; |
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} |
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static int ftrace_modify_code(unsigned long ip, u32 old, u32 new) |
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{ |
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u32 replaced; |
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int faulted; |
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__asm__ __volatile__( |
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"1: cas [%[ip]], %[old], %[new]\n" |
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" flush %[ip]\n" |
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" mov 0, %[faulted]\n" |
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"2:\n" |
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" .section .fixup,#alloc,#execinstr\n" |
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" .align 4\n" |
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"3: sethi %%hi(2b), %[faulted]\n" |
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" jmpl %[faulted] + %%lo(2b), %%g0\n" |
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" mov 1, %[faulted]\n" |
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" .previous\n" |
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" .section __ex_table,\"a\"\n" |
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" .align 4\n" |
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" .word 1b, 3b\n" |
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" .previous\n" |
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: "=r" (replaced), [faulted] "=r" (faulted) |
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: [new] "0" (new), [old] "r" (old), [ip] "r" (ip) |
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: "memory"); |
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if (replaced != old && replaced != new) |
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faulted = 2; |
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return faulted; |
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} |
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int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) |
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{ |
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unsigned long ip = rec->ip; |
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u32 old, new; |
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old = ftrace_call_replace(ip, addr); |
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new = ftrace_nop; |
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return ftrace_modify_code(ip, old, new); |
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} |
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int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) |
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{ |
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unsigned long ip = rec->ip; |
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u32 old, new; |
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old = ftrace_nop; |
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new = ftrace_call_replace(ip, addr); |
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return ftrace_modify_code(ip, old, new); |
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} |
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int ftrace_update_ftrace_func(ftrace_func_t func) |
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{ |
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unsigned long ip = (unsigned long)(&ftrace_call); |
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u32 old, new; |
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old = *(u32 *) &ftrace_call; |
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new = ftrace_call_replace(ip, (unsigned long)func); |
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return ftrace_modify_code(ip, old, new); |
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} |
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int __init ftrace_dyn_arch_init(void) |
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{ |
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return 0; |
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} |
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#endif |
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER |
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#ifdef CONFIG_DYNAMIC_FTRACE |
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extern void ftrace_graph_call(void); |
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int ftrace_enable_ftrace_graph_caller(void) |
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{ |
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unsigned long ip = (unsigned long)(&ftrace_graph_call); |
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u32 old, new; |
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old = *(u32 *) &ftrace_graph_call; |
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new = ftrace_call_replace(ip, (unsigned long) &ftrace_graph_caller); |
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return ftrace_modify_code(ip, old, new); |
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} |
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int ftrace_disable_ftrace_graph_caller(void) |
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{ |
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unsigned long ip = (unsigned long)(&ftrace_graph_call); |
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u32 old, new; |
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old = *(u32 *) &ftrace_graph_call; |
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new = ftrace_call_replace(ip, (unsigned long) &ftrace_stub); |
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return ftrace_modify_code(ip, old, new); |
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} |
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#endif /* !CONFIG_DYNAMIC_FTRACE */ |
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/* |
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* Hook the return address and push it in the stack of return addrs |
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* in current thread info. |
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*/ |
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unsigned long prepare_ftrace_return(unsigned long parent, |
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unsigned long self_addr, |
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unsigned long frame_pointer) |
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{ |
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unsigned long return_hooker = (unsigned long) &return_to_handler; |
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if (unlikely(atomic_read(¤t->tracing_graph_pause))) |
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return parent + 8UL; |
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if (function_graph_enter(parent, self_addr, frame_pointer, NULL)) |
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return parent + 8UL; |
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return return_hooker; |
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} |
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#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
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