 7c10cb38cc
			
		
	
	
		7c10cb38cc
		
	
	
	
	
		
			
			Add libdw-based functions for loading and querying debuginfo. Load debuginfo from the system and the linux-user loaders. This is useful for the upcoming perf support, which can then put human-readable guest symbols instead of raw guest PCs into perfmap and jitdump files. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Message-Id: <20230112152013.125680-3-iii@linux.ibm.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
		
			
				
	
	
		
			97 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			97 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Debug information support.
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|  *
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|  * SPDX-License-Identifier: GPL-2.0-or-later
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|  */
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| 
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| #include "qemu/osdep.h"
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| #include "qemu/lockable.h"
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| 
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| #include <elfutils/libdwfl.h>
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| 
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| #include "debuginfo.h"
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| 
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| static QemuMutex lock;
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| static Dwfl *dwfl;
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| static const Dwfl_Callbacks dwfl_callbacks = {
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|     .find_elf = NULL,
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|     .find_debuginfo = dwfl_standard_find_debuginfo,
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|     .section_address = NULL,
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|     .debuginfo_path = NULL,
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| };
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| 
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| __attribute__((constructor))
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| static void debuginfo_init(void)
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| {
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|     qemu_mutex_init(&lock);
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| }
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| 
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| void debuginfo_report_elf(const char *name, int fd, uint64_t bias)
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| {
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|     QEMU_LOCK_GUARD(&lock);
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| 
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|     if (dwfl) {
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|         dwfl_report_begin_add(dwfl);
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|     } else {
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|         dwfl = dwfl_begin(&dwfl_callbacks);
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|     }
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| 
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|     if (dwfl) {
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|         dwfl_report_elf(dwfl, name, name, fd, bias, true);
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|         dwfl_report_end(dwfl, NULL, NULL);
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|     }
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| }
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| 
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| void debuginfo_lock(void)
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| {
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|     qemu_mutex_lock(&lock);
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| }
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| 
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| void debuginfo_query(struct debuginfo_query *q, size_t n)
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| {
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|     const char *symbol, *file;
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|     Dwfl_Module *dwfl_module;
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|     Dwfl_Line *dwfl_line;
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|     GElf_Off dwfl_offset;
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|     GElf_Sym dwfl_sym;
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|     size_t i;
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|     int line;
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| 
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|     if (!dwfl) {
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|         return;
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|     }
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| 
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|     for (i = 0; i < n; i++) {
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|         dwfl_module = dwfl_addrmodule(dwfl, q[i].address);
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|         if (!dwfl_module) {
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|             continue;
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|         }
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| 
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|         if (q[i].flags & DEBUGINFO_SYMBOL) {
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|             symbol = dwfl_module_addrinfo(dwfl_module, q[i].address,
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|                                           &dwfl_offset, &dwfl_sym,
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|                                           NULL, NULL, NULL);
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|             if (symbol) {
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|                 q[i].symbol = symbol;
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|                 q[i].offset = dwfl_offset;
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|             }
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|         }
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| 
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|         if (q[i].flags & DEBUGINFO_LINE) {
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|             dwfl_line = dwfl_module_getsrc(dwfl_module, q[i].address);
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|             if (dwfl_line) {
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|                 file = dwfl_lineinfo(dwfl_line, NULL, &line, 0, NULL, NULL);
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|                 if (file) {
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|                     q[i].file = file;
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|                     q[i].line = line;
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|                 }
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|             }
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|         }
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|     }
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| }
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| 
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| void debuginfo_unlock(void)
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| {
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|     qemu_mutex_unlock(&lock);
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| }
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