am 90e6f931: Merge "Show maps near native fault address" (08df672a) · Commits · e / os / android_system_core

debuggerd/arm/machine.c

+70 −0

Original line number	Diff line number	Diff line
		@@ -50,6 +50,74 @@ extern int unwind_backtrace_with_ptrace(int tfd, pid_t pid, mapinfo *map,
		int *frame0_pc_sane,
		bool at_fault);

		/*
		* If this isn't clearly a null pointer dereference, dump the
		* /proc/maps entries near the fault address.
		*/
		static void show_nearby_maps(int tfd, int pid, mapinfo *map)
		{
		siginfo_t si;

		memset(&si, 0, sizeof(si));
		if (ptrace(PTRACE_GETSIGINFO, pid, 0, &si)) {
		_LOG(tfd, false, "cannot get siginfo: %s\n", strerror(errno));
		return;
		}
		if (!signal_has_address(si.si_signo))
		return;

		uintptr_t addr = (uintptr_t) si.si_addr;
		addr &= ~0xfff; /* round to 4K page boundary */
		if (addr == 0) /* null-pointer deref */
		return;

		_LOG(tfd, false, "\nmemory map around addr %08x:\n", si.si_addr);

		/*
		* Search for a match, or for a hole where the match would be. The list
		* is backward from the file content, so it starts at high addresses.
		*/
		bool found = false;
		mapinfo *next = NULL;
		mapinfo *prev = NULL;
		while (map != NULL) {
		if (addr >= map->start && addr < map->end) {
		found = true;
		next = map->next;
		break;
		} else if (addr >= map->end) {
		/* map would be between "prev" and this entry */
		next = map;
		map = NULL;
		break;
		}

		prev = map;
		map = map->next;
		}

		/*
		* Show "next" then "match" then "prev" so that the addresses appear in
		* ascending order (like /proc/pid/maps).
		*/
		if (next != NULL) {
		_LOG(tfd, false, "%08x-%08x %s\n", next->start, next->end, next->name);
		} else {
		_LOG(tfd, false, "(no map below)\n");
		}
		if (map != NULL) {
		_LOG(tfd, false, "%08x-%08x %s\n", map->start, map->end, map->name);
		} else {
		_LOG(tfd, false, "(no map for address)\n");
		}
		if (prev != NULL) {
		_LOG(tfd, false, "%08x-%08x %s\n", prev->start, prev->end, prev->name);
		} else {
		_LOG(tfd, false, "(no map above)\n");
		}
		}


		void dump_stack_and_code(int tfd, int pid, mapinfo *map,
		int unwind_depth, unsigned int sp_list[],
		bool at_fault)
		@@ -123,6 +191,8 @@ void dump_stack_and_code(int tfd, int pid, mapinfo *map,
		}
		}

		show_nearby_maps(tfd, pid, map);

		p = sp - 64;
		if (p > sp)
		p = 0;

debuggerd/debuggerd.c

+20 −7

Original line number	Diff line number	Diff line
		@@ -70,15 +70,18 @@ mapinfo parse_maps_line(char line)
		mapinfo *mi;
		int len = strlen(line);

		if(len < 1) return 0;
		if (len < 1) return 0; /* not expected */
		line[--len] = 0;

		if(len < 50) return 0;
		if(line[20] != 'x') return 0;

		if (len < 50) {
		mi = malloc(sizeof(mapinfo) + 1);
		} else {
		mi = malloc(sizeof(mapinfo) + (len - 47));
		}
		if (mi == 0) return 0;

		mi->isExecutable = (line[20] == 'x');

		mi->start = strtoul(line, 0, 16);
		mi->end = strtoul(line + 9, 0, 16);
		/* To be filled in parse_elf_info if the mapped section starts with
		@@ -87,7 +90,11 @@ mapinfo parse_maps_line(char line)
		mi->exidx_start = mi->exidx_end = 0;
		mi->symbols = 0;
		mi->next = 0;
		if (len < 50) {
		mi->name[0] = '\0';
		} else {
		strcpy(mi->name, line + 49);
		}

		return mi;
		}
		@@ -165,11 +172,14 @@ void dump_fault_addr(int tfd, int pid, int sig)
		memset(&si, 0, sizeof(si));
		if(ptrace(PTRACE_GETSIGINFO, pid, 0, &si)){
		_LOG(tfd, false, "cannot get siginfo: %s\n", strerror(errno));
		} else {
		} else if (signal_has_address(sig)) {
		_LOG(tfd, false, "signal %d (%s), code %d (%s), fault addr %08x\n",
		sig, get_signame(sig),
		si.si_code, get_sigcode(sig, si.si_code),
		si.si_addr);
		} else {
		_LOG(tfd, false, "signal %d (%s), code %d (%s), fault addr --------\n",
		sig, get_signame(sig), si.si_code, get_sigcode(sig, si.si_code));
		}
		}

		@@ -199,6 +209,9 @@ static void parse_elf_info(mapinfo *milist, pid_t pid)
		{
		mapinfo *mi;
		for (mi = milist; mi != NULL; mi = mi->next) {
		if (!mi->isExecutable)
		continue;

		Elf32_Ehdr ehdr;

		memset(&ehdr, 0, sizeof(Elf32_Ehdr));

debuggerd/utility.c

+18 −0

Original line number	Diff line number	Diff line
		@@ -17,6 +17,7 @@

		#include <sys/ptrace.h>
		#include <sys/exec_elf.h>
		#include <signal.h>
		#include <assert.h>
		#include <string.h>
		#include <errno.h>
		@@ -82,3 +83,20 @@ const mapinfo pc_to_mapinfo(mapinfo mi, unsigned pc, unsigned *rel_pc)
		}
		return NULL;
		}

		/*
		* Returns true if the specified signal has an associated address (i.e. it
		* sets siginfo_t.si_addr).
		*/
		bool signal_has_address(int sig)
		{
		switch (sig) {
		case SIGILL:
		case SIGFPE:
		case SIGSEGV:
		case SIGBUS:
		return true;
		default:
		return false;
		}
		}

debuggerd/utility.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -36,6 +36,7 @@ typedef struct mapinfo {
		unsigned exidx_start;
		unsigned exidx_end;
		struct symbol_table *symbols;
		bool isExecutable;
		char name[];
		} mapinfo;

		@@ -56,6 +57,9 @@ const char map_to_name(mapinfo mi, unsigned pc, const char* def);
		/* Log information onto the tombstone */
		extern void _LOG(int tfd, bool in_tombstone_only, const char *fmt, ...);

		/* Determine whether si_addr is valid for this signal */
		bool signal_has_address(int sig);

		#define LOG(fmt...) _LOG(-1, 0, fmt)

		/* Set to 1 for normal debug traces */