[pypy-commit] pypy vmprof: Rewrite addresses to point to the start of JIT code

[fijal]

Author: Maciej Fijalkowski <fijall at gmail.com>
Branch: vmprof
Changeset: r76672:a3d990e5c7d4
Date: 2015-04-01 14:16 +0200
http://bitbucket.org/pypy/pypy/changeset/a3d990e5c7d4/

Log:	Rewrite addresses to point to the start of JIT code

diff --git a/pypy/module/_vmprof/src/get_custom_offset.c b/pypy/module/_vmprof/src/get_custom_offset.c
--- a/pypy/module/_vmprof/src/get_custom_offset.c
+++ b/pypy/module/_vmprof/src/get_custom_offset.c
@@ -13,31 +13,37 @@
 
 int custom_sanity_check()
 {
-	return !pypy_codemap_currently_invalid;
+    return !pypy_codemap_currently_invalid;
 }
 
 static ptrdiff_t vmprof_unw_get_custom_offset(void* ip, unw_cursor_t *cp) {
-	intptr_t ip_l = (intptr_t)ip;
-	return pypy_jit_stack_depth_at_loc(ip_l);
+    intptr_t ip_l = (intptr_t)ip;
+    return pypy_jit_stack_depth_at_loc(ip_l);
 }
 
 static long vmprof_write_header_for_jit_addr(void **result, long n,
-											 void *ip, int max_depth)
+                                             void *ip, int max_depth)
 {
-	void *codemap;
-	long current_pos = 0;
-	intptr_t id;
-	intptr_t addr = (intptr_t)ip;
+    void *codemap;
+    long current_pos = 0;
+    intptr_t id;
+    long start_addr = 0;
+    intptr_t addr = (intptr_t)ip;
 
-	codemap = pypy_find_codemap_at_addr(addr);
-	if (codemap == NULL)
-		return n;
+    codemap = pypy_find_codemap_at_addr(addr, &start_addr);
+    if (codemap == NULL)
+        // not a jit code at all
+        return n;
 
-	while (n < max_depth) {
-		id = pypy_yield_codemap_at_addr(codemap, addr, &current_pos);
-		if (id == 0)
-			break;
-		result[n++] = (void *)id;
-	}
-	return n;
+    // modify the last entry to point to start address and not the random one
+    // in the middle
+    result[n - 1] = (void*)start_addr;
+    while (n < max_depth) {
+        id = pypy_yield_codemap_at_addr(codemap, addr, &current_pos);
+        if (id == 0)
+            // finish
+            break;
+        result[n++] = (void *)id;
+    }
+    return n;
 }
diff --git a/rpython/jit/backend/llsupport/src/codemap.c b/rpython/jit/backend/llsupport/src/codemap.c
--- a/rpython/jit/backend/llsupport/src/codemap.c
+++ b/rpython/jit/backend/llsupport/src/codemap.c
@@ -76,12 +76,13 @@
 /*** interface used from pypy/module/_vmprof ***/
 
 RPY_EXTERN
-void *pypy_find_codemap_at_addr(long addr)
+void *pypy_find_codemap_at_addr(long addr, long* start_addr)
 {
     skipnode_t *codemap = skiplist_search(&jit_codemap_head, addr);
     codemap_data_t *data;
     uintptr_t rel_addr;
 
+    *start_addr = 0;
     if (codemap == &jit_codemap_head)
         return NULL;
 
@@ -90,6 +91,7 @@
     if (rel_addr >= data->machine_code_size)
         return NULL;
 
+    *start_addr = (long)codemap->key;
     return (void *)codemap;
 }