Re: [PATCH v4] kdb: kdb_support: Fix debugging information problem

[Daniel Thompson]

On Thu, Feb 04, 2021 at 08:07:09PM +0800, Stephen Zhang wrote:
> There are several common patterns.
> 
> 0:
> kdb_printf("...",...);
> 
> which is the normal one.
> 
> 1:
> kdb_printf("%s: "...,__func__,...)
> 
> We could improve '1' to this :
> 
> #define kdb_func_printf(format, args...) \
>kdb_printf("%s: " format, __func__, ## args)
> 
> 2:
> if(KDB_DEBUG(AR))
> kdb_printf("%s "...,__func__,...);
> 
> We could improve '2' to this :
> #define kdb_dbg_printf(mask, format, args...) \
>do { \
> if (KDB_DEBUG(mask)) \
> kdb_func_printf(format, ## 
> args); \

This line is picked up by checkpatch as being overlong.

>} while (0)
> 
> In additon, we changed the format code of size_t to %zu.

Should be `addition`.



> Signed-off-by: Stephen Zhang 

It is arguable that there should be a Reviewed-by: from Doug here...
although given the big changes in v3 I don't think you were wrong
to drop it.

Nevertheless... given the implicit R-b ("when Daniel merges") in Doug's
comments on v3 I decided to reinstate it.

No action needed from you on this. I have fixed up all these issues
when I applied the patch. Thanks!


Daniel.

[PATCH v4] kdb: kdb_support: Fix debugging information problem

[Stephen Zhang]

There are several common patterns.

0:
kdb_printf("...",...);

which is the normal one.

1:
kdb_printf("%s: "...,__func__,...)

We could improve '1' to this :

#define kdb_func_printf(format, args...) \
   kdb_printf("%s: " format, __func__, ## args)

2:
if(KDB_DEBUG(AR))
kdb_printf("%s "...,__func__,...);

We could improve '2' to this :
#define kdb_dbg_printf(mask, format, args...) \
   do { \
if (KDB_DEBUG(mask)) \
kdb_func_printf(format, ## 
args); \
   } while (0)

In additon, we changed the format code of size_t to %zu.

Signed-off-by: Stephen Zhang 
---
v1->v2 Changelog:
- Add 'mask' parameter in kdb_dbg_printf()

Thanks to Daniel and Doug's suggestions and review.

v2->v4 Changelog:
- Adjust alignment for some lines.

Suggested by Douglas Anderson.

 kernel/debug/kdb/kdb_private.h | 10 
 kernel/debug/kdb/kdb_support.c | 53 --
 2 files changed, 30 insertions(+), 33 deletions(-)

diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index a4281fb..0a56d35 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -254,4 +254,14 @@ extern unsigned long kdb_task_state(const struct 
task_struct *p,
 #defineKDB_WORD_SIZE   ((int)sizeof(unsigned long))
 
 #endif /* CONFIG_KGDB_KDB */
+
+#define kdb_func_printf(format, args...) \
+   kdb_printf("%s: " format, __func__, ## args)
+
+#define kdb_dbg_printf(mask, format, args...) \
+   do { \
+   if (KDB_DEBUG(mask)) \
+   kdb_func_printf(format, ## args); \
+   } while (0)
+
 #endif /* !_KDBPRIVATE_H */
diff --git a/kernel/debug/kdb/kdb_support.c b/kernel/debug/kdb/kdb_support.c
index 6226502..f7c1885 100644
--- a/kernel/debug/kdb/kdb_support.c
+++ b/kernel/debug/kdb/kdb_support.c
@@ -39,20 +39,15 @@
  */
 int kdbgetsymval(const char *symname, kdb_symtab_t *symtab)
 {
-   if (KDB_DEBUG(AR))
-   kdb_printf("kdbgetsymval: symname=%s, symtab=%px\n", symname,
-  symtab);
+   kdb_dbg_printf(AR, "symname=%s, symtab=%px\n", symname, symtab);
memset(symtab, 0, sizeof(*symtab));
symtab->sym_start = kallsyms_lookup_name(symname);
if (symtab->sym_start) {
-   if (KDB_DEBUG(AR))
-   kdb_printf("kdbgetsymval: returns 1, "
-  "symtab->sym_start=0x%lx\n",
-  symtab->sym_start);
+   kdb_dbg_printf(AR, "returns 1, symtab->sym_start=0x%lx\n",
+  symtab->sym_start);
return 1;
}
-   if (KDB_DEBUG(AR))
-   kdb_printf("kdbgetsymval: returns 0\n");
+   kdb_dbg_printf(AR, "returns 0\n");
return 0;
 }
 EXPORT_SYMBOL(kdbgetsymval);
@@ -87,16 +82,14 @@ int kdbnearsym(unsigned long addr, kdb_symtab_t *symtab)
 #define knt1_size 128  /* must be >= kallsyms table size */
char *knt1 = NULL;
 
-   if (KDB_DEBUG(AR))
-   kdb_printf("kdbnearsym: addr=0x%lx, symtab=%px\n", addr, 
symtab);
+   kdb_dbg_printf(AR, "addr=0x%lx, symtab=%px\n", addr, symtab);
memset(symtab, 0, sizeof(*symtab));
 
if (addr < 4096)
goto out;
knt1 = debug_kmalloc(knt1_size, GFP_ATOMIC);
if (!knt1) {
-   kdb_printf("kdbnearsym: addr=0x%lx cannot kmalloc knt1\n",
-  addr);
+   kdb_func_printf("addr=0x%lx cannot kmalloc knt1\n", addr);
goto out;
}
symtab->sym_name = kallsyms_lookup(addr,  , ,
@@ -147,11 +140,8 @@ int kdbnearsym(unsigned long addr, kdb_symtab_t *symtab)
 
if (symtab->mod_name == NULL)
symtab->mod_name = "kernel";
-   if (KDB_DEBUG(AR))
-   kdb_printf("kdbnearsym: returns %d symtab->sym_start=0x%lx, "
-  "symtab->mod_name=%px, symtab->sym_name=%px (%s)\n", ret,
-  symtab->sym_start, symtab->mod_name, symtab->sym_name,
-  symtab->sym_name);
+   kdb_dbg_printf(AR, "returns %d symtab->sym_start=0x%lx, 
symtab->mod_name=%px, symtab->sym_name=%px (%s)\n",
+  ret, symtab->sym_start, symtab->mod_name, 
symtab->sym_name, symtab->sym_name);
 
 out:
debug_kfree(knt1);
@@ -328,7 +318,7 @@ int kdb_getarea_size(void *res, unsigned long addr, size_t 
size)
int ret = copy_from_kernel_nofault((char *)res, (char *)addr, size);
if (ret) {
if (!KDB_STATE(SUPPRESS)) {
-   kdb_printf("kdb_getarea: Bad address 0x%lx\n", addr);
+   kdb_func_printf("Bad address 0x%lx\n", addr);
KDB_STATE_SET(SUPPRESS);
}
ret = KDB_BADADDR;
@@