Merge "Show maps near native fault address"
diff --git a/debuggerd/arm/machine.c b/debuggerd/arm/machine.c
index 88bf054..58a7839 100644
--- a/debuggerd/arm/machine.c
+++ b/debuggerd/arm/machine.c
@@ -50,6 +50,74 @@
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 @@
}
}
+ show_nearby_maps(tfd, pid, map);
+
p = sp - 64;
if (p > sp)
p = 0;
diff --git a/debuggerd/debuggerd.c b/debuggerd/debuggerd.c
index d03c214..97a6b9e 100644
--- a/debuggerd/debuggerd.c
+++ b/debuggerd/debuggerd.c
@@ -70,14 +70,17 @@
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 = 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);
@@ -87,7 +90,11 @@
mi->exidx_start = mi->exidx_end = 0;
mi->symbols = 0;
mi->next = 0;
- strcpy(mi->name, line + 49);
+ if (len < 50) {
+ mi->name[0] = '\0';
+ } else {
+ strcpy(mi->name, line + 49);
+ }
return mi;
}
@@ -165,11 +172,14 @@
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 @@
{
mapinfo *mi;
for (mi = milist; mi != NULL; mi = mi->next) {
+ if (!mi->isExecutable)
+ continue;
+
Elf32_Ehdr ehdr;
memset(&ehdr, 0, sizeof(Elf32_Ehdr));
diff --git a/debuggerd/utility.c b/debuggerd/utility.c
index 2afdb46..409209c 100644
--- a/debuggerd/utility.c
+++ b/debuggerd/utility.c
@@ -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 @@
}
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;
+ }
+}
diff --git a/debuggerd/utility.h b/debuggerd/utility.h
index 45e2067..4a935d2 100644
--- a/debuggerd/utility.h
+++ b/debuggerd/utility.h
@@ -36,6 +36,7 @@
unsigned exidx_start;
unsigned exidx_end;
struct symbol_table *symbols;
+ bool isExecutable;
char name[];
} mapinfo;
@@ -56,6 +57,9 @@
/* 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 */