Re: [PATCH v8 6/6] powerpc/fadump: use the new parse_args callback arguments

From: Hari Bathini
Date: Fri Sep 29 2017 - 09:00:39 EST


In case, someone wishes for a changelog:


With fadump_rework_cmdline_params() function, parse_args() callback function,

taking new arguments - current & next, use them to process 'fadump_extra_args='

parmeter, in enforcing the parameters passed through it for fadump kernel.


On Tuesday 12 September 2017 09:31 PM, Michal Suchanek wrote:
Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
---
arch/powerpc/kernel/fadump.c | 47 ++++++++++++--------------------------------
1 file changed, 13 insertions(+), 34 deletions(-)

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 8778e1cc0380..1678d99ea835 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -481,33 +481,19 @@ struct param_info {
};

static void __init fadump_update_params(struct param_info *param_info,
- char *param, char *val)
+ char *param, char *val,
+ char *currant, char *next)
{
- ptrdiff_t param_offset = param - param_info->tmp_cmdline;
+ ptrdiff_t param_offset = currant - param_info->tmp_cmdline;
size_t vallen = val ? strlen(val) : 0;
char *tgt = param_info->cmdline + param_offset
- param_info->shortening;
- int shortening = 0;
- int quoted = 0;
+ int shortening = ((next - 1) - (currant))
+ - (FADUMP_EXTRA_ARGS_LEN + 1 + vallen);

if (!val)
return;

- /* leading '"' removed from parameter */
- if ((param > param_info->tmp_cmdline) && *(param - 1) == '"') {
- quoted = 1;
- shortening += 1;
- tgt--;
- }
-
- /* next_arg removes one leading and one trailing '"' */
- if ((*(tgt + FADUMP_EXTRA_ARGS_LEN + 1 + vallen + shortening) == '"') &&
- (quoted || (*(tgt + FADUMP_EXTRA_ARGS_LEN + 1) == '"'))) {
- shortening += 1;
- if (!quoted)
- shortening += 1;
- }
-
/* remove one leading and one trailing quote if both are present */
if ((val[0] == '"') && (val[vallen - 1] == '"')) {
shortening += 2;
@@ -515,22 +501,15 @@ static void __init fadump_update_params(struct param_info *param_info,
val++;
}

- /* some characters were removed - move the trailing part of cmdline */
- if (shortening) {
- char *src;
+ strncpy(tgt, FADUMP_EXTRA_ARGS_PARAM, FADUMP_EXTRA_ARGS_LEN);
+ tgt += FADUMP_EXTRA_ARGS_LEN;
+ *tgt++ = ' ';
+ strncpy(tgt, val, vallen);
+ tgt += vallen;

- strncpy(tgt, FADUMP_EXTRA_ARGS_PARAM, FADUMP_EXTRA_ARGS_LEN);
- tgt += FADUMP_EXTRA_ARGS_LEN;
- *tgt++ = ' ';
-
- strncpy(tgt, val, vallen);
- tgt += vallen;
-
- src = tgt + shortening;
+ if (shortening) {
+ char *src = tgt + shortening;
memmove(tgt, src, strlen(src) + 1);
- } else {
- /* remove the '=' */
- *(tgt + FADUMP_EXTRA_ARGS_LEN) = ' ';
}

param_info->shortening += shortening;
@@ -550,7 +529,7 @@ static int __init fadump_rework_cmdline_params(char *param, char *val,
strlen(FADUMP_EXTRA_ARGS_PARAM) - 1))
return 0;

- fadump_update_params(param_info, param, val);
+ fadump_update_params(param_info, param, val, currant, next);

return 0;
}


Thanks
Hari