[S] Change in flashrom[master]: programmer_init: Work on a mutable copy of programmer params

[Angel Pons (Code Review)]

Angel Pons has submitted this change. ( https://review.coreboot.org/c/flashrom/+/67094 )

Change subject: programmer_init: Work on a mutable copy of programmer params
......................................................................

programmer_init: Work on a mutable copy of programmer params

The signature of extract_param() was wrong all the time. It actually
modifies the passed, global `programmer_param` string. This only com-
piled w/o warnings because of a deficiency of the strstr() API. It
takes a const string as argument but returns a mutable pointer to
a substring of it.

As we take a const parameter string in the libflashrom API and should
not change that, we create a copy in programmer_init() instead.

Now that we free our copy of the programmer parameters at the end of
programmer_init() it's more obvious that the string can only be used
during initialization. So also clear `programmer_param` inside
programmer_init() instead of programmer_shutdown().

Change-Id: If6bb2e5e4312b07f756615984bd3757e92b86b0a
Signed-off-by: Nico Huber 
Reviewed-on: https://review.coreboot.org/c/flashrom/+/67094
Tested-by: build bot (Jenkins) 
Reviewed-by: Angel Pons 
Reviewed-by: Edward O'Callaghan 
Reviewed-by: Thomas Heijligen 
---
M flashrom.c
1 file changed, 43 insertions(+), 5 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Thomas Heijligen: Looks good to me, approved
  Angel Pons: Looks good to me, approved
  Edward O'Callaghan: Looks good to me, approved

diff --git a/flashrom.c b/flashrom.c
index b68ba55..f8c5e73 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -38,7 +38,7 @@
 const char *chip_to_probe = NULL;

static const struct programmer_entry *programmer = NULL;
-static const char *programmer_param = NULL;
+static char *programmer_param = NULL;

/*
  * Programmers supporting multiple buses can have differing size limits on
@@ -150,7 +150,16 @@
    /* Default to allowing writes. Broken programmers set this to 0. */
    programmer_may_write = true;

-	programmer_param = param;
+	if (param) {
+		programmer_param = strdup(param);
+		if (!programmer_param) {
+			msg_perr("Out of memory!\n");
+			return ERROR_FATAL;
+		}
+	} else {
+		programmer_param = NULL;
+	}
+
    msg_pdbg("Initializing %s programmer\n", programmer->name);
    ret = programmer->init(NULL);
    if (programmer_param && strlen(programmer_param)) {
@@ -169,6 +178,8 @@
    		ret = ERROR_FATAL;
    	}
    }
+	free(programmer_param);
+	programmer_param = NULL;
    return ret;
 }

@@ -187,8 +198,6 @@
    	int i = --shutdown_fn_count;
    	ret |= shutdown_fn[i].func(shutdown_fn[i].data);
    }
-
-	programmer_param = NULL;
    registered_master_count = 0;

return ret;
@@ -227,7 +236,7 @@
  * needle and remove everything from the first occurrence of needle to the next
  * delimiter from haystack.
  */
-static char *extract_param(const char *const *haystack, const char *needle, const char *delim)
+static char *extract_param(char *const *haystack, const char *needle, const char *delim)
 {
    char *param_pos, *opt_pos, *rest;
    char *opt = NULL;