[Xen-devel] [PATCH v3 20/23] x86, xsplice: Print payload's symbol name and module in backtraces

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

From: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>

Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
 xen/arch/x86/traps.c      |  6 +++---
 xen/common/vsprintf.c     | 18 ++++++++++++++--
 xen/common/xsplice.c      | 52 +++++++++++++++++++++++++++++++++++++++++++----
 xen/include/xen/xsplice.h | 11 ++++++++++
 4 files changed, 78 insertions(+), 9 deletions(-)

diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index f3adefa..36d42fe 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -341,7 +341,7 @@ static void _show_trace(unsigned long sp, unsigned long 
__maybe_unused bp)
     while ( stack <= bottom )
     {
         addr = *stack++;
-        if ( is_active_kernel_text(addr) )
+        if ( is_active_text(addr) )
             printk("   [<%p>] %pS\n", _p(addr), _p(addr));
     }
 }
@@ -403,8 +403,8 @@ static void show_trace(const struct cpu_user_regs *regs)
      * If RIP looks sensible, or the top of the stack doesn't, print RIP at
      * the top of the stack trace.
      */
-    if ( is_active_kernel_text(regs->rip) ||
-         !is_active_kernel_text(*sp) )
+    if ( is_active_text(regs->rip) ||
+         !is_active_text(*sp) )
         printk("   [<%p>] %pS\n", _p(regs->rip), _p(regs->rip));
     /*
      * Else RIP looks bad but the top of the stack looks good.  Perhaps we
diff --git a/xen/common/vsprintf.c b/xen/common/vsprintf.c
index 51b5e4e..cfe63a4 100644
--- a/xen/common/vsprintf.c
+++ b/xen/common/vsprintf.c
@@ -20,6 +20,7 @@
 #include <xen/symbols.h>
 #include <xen/lib.h>
 #include <xen/sched.h>
+#include <xen/xsplice.h>
 #include <asm/div64.h>
 #include <asm/page.h>
 
@@ -305,15 +306,21 @@ static char *pointer(char *str, char *end, const char 
**fmt_ptr,
     {
         unsigned long sym_size, sym_offset;
         char namebuf[KSYM_NAME_LEN+1];
+        const char *module = NULL;
 
         /* Advance parents fmt string, as we have consumed 's' or 'S' */
         ++*fmt_ptr;
 
         s = symbols_lookup((unsigned long)arg, &sym_size, &sym_offset, 
namebuf);
 
-        /* If the symbol is not found, fall back to printing the address */
         if ( !s )
-            break;
+        {
+            s = xsplice_symbols_lookup((unsigned long)arg, &sym_size,
+                                       &sym_offset, &module);
+            /* If the symbol is not found, fall back to printing the address */
+            if ( !s )
+                break;
+        }
 
         /* Print symbol name */
         str = string(str, end, s, -1, -1, 0);
@@ -328,6 +335,13 @@ static char *pointer(char *str, char *end, const char 
**fmt_ptr,
             str = number(str, end, sym_size, 16, -1, -1, SPECIAL);
         }
 
+        if ( module )
+        {
+            str = string(str, end, " [", -1, -1, 0);
+            str = string(str, end, module, -1, -1, 0);
+            str = string(str, end, "]", -1, -1, 0);
+        }
+
         return str;
     }
 
diff --git a/xen/common/xsplice.c b/xen/common/xsplice.c
index 0b42a16..ae2882f 100644
--- a/xen/common/xsplice.c
+++ b/xen/common/xsplice.c
@@ -873,7 +873,6 @@ static int build_symbol_table(struct payload *payload, 
struct xsplice_elf *elf)
             symtab[nsyms].name = strtab + strtab_len;
             symtab[nsyms].size = elf->sym[i].sym->st_size;
             symtab[nsyms].value = elf->sym[i].sym->st_value;
-            symtab[nsyms].flags = 0;
             strtab_len += strlcpy(strtab + strtab_len, elf->sym[i].name,
                                   KSYM_NAME_LEN) + 1;
             nsyms++;
@@ -1276,7 +1275,7 @@ struct bug_frame *xsplice_find_bug(const char *eip, int 
*id)
 {
     struct payload *data;
     struct bug_frame *bug;
-    int i;
+    unsigned int i;
 
     /* No locking since this list is only ever changed during apply or revert
      * context. */
@@ -1286,10 +1285,12 @@ struct bug_frame *xsplice_find_bug(const char *eip, int 
*id)
             if (!data->start_bug_frames[i])
                 continue;
             if ( !((void *)eip >= data->payload_address &&
-                   (void *)eip < (data->payload_address + 
data->core_text_size)))
+                   (void *)eip < (data->payload_address + 
data->core_text_size)) )
                 continue;
 
-            for ( bug = data->start_bug_frames[i]; bug != 
data->stop_bug_frames[i]; ++bug ) {
+            for ( bug = data->start_bug_frames[i];
+                  bug != data->stop_bug_frames[i]; ++bug )
+            {
                 if ( bug_loc(bug) == eip )
                 {
                     *id = i;
@@ -1385,6 +1386,49 @@ out:
     return value;
 }
 
+const char *xsplice_symbols_lookup(unsigned long addr,
+                                   unsigned long *symbolsize,
+                                   unsigned long *offset,
+                                   const char **module)
+{
+    struct payload *data;
+    unsigned int i;
+    int best;
+
+    /* No locking since this list is only ever changed during apply or revert
+     * context. */
+    list_for_each_entry ( data, &applied_list, applied_list )
+    {
+        if ( !((void *)addr >= data->payload_address &&
+               (void *)addr < (data->payload_address + data->core_text_size)) )
+            continue;
+
+        best = -1;
+
+        for ( i = 0; i < data->nsyms; i++ )
+        {
+            if ( data->symtab[i].value <= addr &&
+                 ( best == -1 ||
+                   data->symtab[best].value < data->symtab[i].value) )
+                best = i;
+        }
+
+        if ( best == -1 )
+            return NULL;
+
+        if ( symbolsize )
+            *symbolsize = data->symtab[best].size;
+        if ( offset )
+            *offset = addr - data->symtab[best].value;
+        if ( module )
+            *module = data->name;
+
+        return data->symtab[best].name;
+    }
+
+    return NULL;
+}
+
 static int __init xsplice_init(void)
 {
     register_keyhandler('x', xsplice_printall, "print xsplicing info", 1);
diff --git a/xen/include/xen/xsplice.h b/xen/include/xen/xsplice.h
index 1045213..482483b 100644
--- a/xen/include/xen/xsplice.h
+++ b/xen/include/xen/xsplice.h
@@ -43,6 +43,10 @@ bool_t is_module(const void *addr);
 bool_t is_active_module_text(unsigned long addr);
 unsigned long search_module_extables(unsigned long addr);
 uint64_t xsplice_symbols_lookup_by_name(const char *symname);
+const char *xsplice_symbols_lookup(unsigned long addr,
+                                   unsigned long *symbolsize,
+                                   unsigned long *offset,
+                                   const char **module);
 
 /* Arch hooks */
 int xsplice_verify_elf(struct xsplice_elf *elf, uint8_t *data);
@@ -77,5 +81,12 @@ static inline unsigned long search_module_extables(unsigned 
long addr)
 {
        return 0;
 }
+static inline const char *xsplice_symbols_lookup(unsigned long addr,
+                                                 unsigned long *symbolsize,
+                                                 unsigned long *offset,
+                                                 const char **module)
+{
+    return NULL;
+}
 #endif
 #endif /* __XEN_XSPLICE_H__ */
-- 
2.1.0


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