[PATCHv3 4/9] modpost: provide better diagnostics for __init / __exit strings

Mathias Krause
2014-08-21T12:26:32Z

Modpost will detect wrong usage of the pe_*() / pi_*() macros or the
__init_str() / __exit_str() annotations in general. But it'll print
cryptic diagnoses in this case that don't really help fixing the issue
in the code. Detect __init / __exit string section mismatches by there
unique symbol name pattern and provide better help texts in this case.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
---
This patch generates quite a few checkpatch warnings related to strings
split across lines. But I choose to do so anyway to not make the code
differ from other fprintf()s in this file.

scripts/mod/modpost.c | 94 +++++++++++++++++++++++++++++++++++++++----------
1 file changed, 75 insertions(+), 19 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 091d90573b..7b462d5d01 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1150,6 +1150,16 @@ static inline int is_arm_mapping_symbol(const char *str)
&& (str[2] == '\0' || str[2] == '.');
}

+static inline int is_init_str(const char *str)
+{
+ return !strncmp(str, "__UNIQUE_ID__init_str_", 22);
+}
+
+static inline int is_exit_str(const char *str)
+{
+ return !strncmp(str, "__UNIQUE_ID__exit_str_", 22);
+}
+
/*
* If there's no name there, ignore it; likewise, ignore it if it's
* one of the magic symbols emitted used by current ARM tools.
@@ -1305,12 +1315,24 @@ static void report_sec_mismatch(const char *modname,
prl_to = sec2annotation(tosec);
fprintf(stderr,
"The function %s%s() references\n"
- "the %s %s%s%s.\n"
- "This is often because %s lacks a %s\n"
- "annotation or the annotation of %s is wrong.\n",
+ "the %s %s%s%s.\n",
prl_from, fromsym,
- to, prl_to, tosym, to_p,
- fromsym, prl_to, tosym);
+ to, prl_to, tosym, to_p);
+ if (!to_is_func && is_init_str(tosym)) {
+ fprintf(stderr,
+ "This is probably due to a wrong use of the "
+ "pi_<level>() macro\n"
+ "or a wrongly __init_str() annotated string literal.\n"
+ "The fix is to either change the pi_<level>() to its "
+ "pr_<level>()\n"
+ "counterpart or to remove the __init_str() annotation "
+ "of the string literal\n");
+ } else {
+ fprintf(stderr,
+ "This is often because %s lacks a %s\n"
+ "annotation or the annotation of %s is wrong.\n",
+ fromsym, prl_to, tosym);
+ }
free(prl_from);
free(prl_to);
break;
@@ -1330,10 +1352,24 @@ static void report_sec_mismatch(const char *modname,
case TEXT_TO_ANY_EXIT:
prl_to = sec2annotation(tosec);
fprintf(stderr,
- "The function %s() references a %s in an exit section.\n"
- "Often the %s %s%s has valid usage outside the exit section\n"
- "and the fix is to remove the %sannotation of %s.\n",
- fromsym, to, to, tosym, to_p, prl_to, tosym);
+ "The function %s() references a %s in an exit section.\n",
+ fromsym, to);
+ if (!to_is_func && is_exit_str(tosym)) {
+ fprintf(stderr,
+ "This is probably due to a wrong use of the "
+ "pe_<level>() macro\n"
+ "or a wrongly __exit_str() annotated string literal.\n"
+ "The fix is to either change the pe_<level>() to its "
+ "pr_<level>()\n"
+ "counterpart or to remove the __exit_str() annotation "
+ "of the string literal\n");
+ } else {
+ fprintf(stderr,
+ "Often the %s %s%s has valid usage outside the exit "
+ "section\n"
+ "and the fix is to remove the %sannotation of %s.\n",
+ to, tosym, to_p, prl_to, tosym);
+ }
free(prl_to);
break;
case DATA_TO_ANY_EXIT: {
@@ -1372,12 +1408,22 @@ static void report_sec_mismatch(const char *modname,
"a %s %s%s%s.\n"
"This is often seen when error handling "
"in the init function\n"
- "uses functionality in the exit path.\n"
- "The fix is often to remove the %sannotation of\n"
- "%s%s so it may be used outside an exit section.\n",
+ "uses functionality of the exit path.\n",
from, prl_from, fromsym, from_p,
- to, prl_to, tosym, to_p,
- prl_to, tosym, to_p);
+ to, prl_to, tosym, to_p);
+ if (!to_is_func && is_exit_str(tosym)) {
+ fprintf(stderr,
+ "The fix is often to either change the pe_<level>() to "
+ "its pr_<level>()\n"
+ "counterpart or to remove the __exit_str() annotation "
+ "of the string literal\n"
+ "so it may be used outside an exit section.\n");
+ } else {
+ fprintf(stderr,
+ "The fix is often to remove the %sannotation of\n"
+ "%s%s so it may be used outside an exit section.\n",
+ prl_to, tosym, to_p);
+ }
free(prl_from);
free(prl_to);
break;
@@ -1389,12 +1435,22 @@ static void report_sec_mismatch(const char *modname,
"a %s %s%s%s.\n"
"This is often seen when error handling "
"in the exit function\n"
- "uses functionality in the init path.\n"
- "The fix is often to remove the %sannotation of\n"
- "%s%s so it may be used outside an init section.\n",
+ "uses functionality of the init path.\n",
from, prl_from, fromsym, from_p,
- to, prl_to, tosym, to_p,
- prl_to, tosym, to_p);
+ to, prl_to, tosym, to_p);
+ if (!to_is_func && is_init_str(tosym)) {
+ fprintf(stderr,
+ "The fix is often to either change the pi_<level>() to "
+ "its pr_<level>()\n"
+ "counterpart or to remove the __init_str() annotation "
+ "of the string literal\n"
+ "so it may be used outside an init section.\n");
+ } else {
+ fprintf(stderr,
+ "The fix is often to remove the %sannotation of\n"
+ "%s%s so it may be used outside an init section.\n",
+ prl_to, tosym, to_p);
+ }
free(prl_from);
free(prl_to);
break;
--
1.7.10.4