Change in coreboot[master]: amdfwtool: Pack out-of-bounds check into a function and move

[Felix Held (Code Review)]

Felix Held has submitted this change. ( https://review.coreboot.org/c/coreboot/+/58764 )

Change subject: amdfwtool: Pack out-of-bounds check into a function and move
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amdfwtool: Pack out-of-bounds check into a function and move

Need to check the FWs number limit several times. So pack the
duplicated steps into a function. And do it before access the new
entry.

Change-Id: I71117d1c817c0b6ddaea4ea47aea91672cc6d55a
Signed-off-by: Zheng Bao 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58764
Tested-by: build bot (Jenkins) 
Reviewed-by: Felix Held 
---
M util/amdfwtool/amdfwtool.c
1 file changed, 15 insertions(+), 13 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Felix Held: Looks good to me, approved

diff --git a/util/amdfwtool/amdfwtool.c b/util/amdfwtool/amdfwtool.c
index 049755b..b10315e 100644
--- a/util/amdfwtool/amdfwtool.c
+++ b/util/amdfwtool/amdfwtool.c
@@ -354,6 +354,16 @@
 #define BUFF_TO_RUN(ctx, ptr) RUN_OFFSET((ctx), ((char *)(ptr) - (ctx).rom))
 #define BUFF_ROOM(ctx) ((ctx).rom_size - (ctx).current)

+void assert_fw_entry(uint32_t count, uint32_t max, context *ctx)
+{
+	if (count >= max) {
+		fprintf(stderr, "Error: BIOS entries (%d) exceeds max allowed items "
+			"(%d)\n", count, max);
+		free(ctx->rom);
+		exit(1);
+	}
+}
+
 static void *new_psp_dir(context *ctx, int multi)
 {
    void *ptr;
@@ -653,6 +663,8 @@
    	if (!(fw_table[i].level & level))
    		continue;

+		assert_fw_entry(count, MAX_PSP_ENTRIES, ctx);
+
    	if (fw_table[i].type == AMD_TOKEN_UNLOCK) {
    		if (!fw_table[i].other)
    			continue;
@@ -719,6 +731,7 @@
    }

if (pspdir2) {
+		assert_fw_entry(count, MAX_PSP_ENTRIES, ctx);
    	pspdir->entries[count].type = AMD_FW_L2_PTR;
    	pspdir->entries[count].subprog = 0;
    	pspdir->entries[count].rsvd = 0;
@@ -730,12 +743,6 @@
    	count++;
    }

-	if (count > MAX_PSP_ENTRIES) {
-		fprintf(stderr, "Error: PSP entries exceed max allowed items\n");
-		free(ctx->rom);
-		exit(1);
-	}
-
    fill_dir_header(pspdir, count, cookie, ctx);
 }

@@ -888,6 +895,7 @@
    	if (fw_table[i].type == AMD_BIOS_PSP_SHARED_MEM &&
    			(!fw_table[i].dest || !fw_table[i].size))
    		continue;
+		assert_fw_entry(count, MAX_BIOS_ENTRIES, ctx);

biosdir->entries[count].type = fw_table[i].type;
    	biosdir->entries[count].region_type = fw_table[i].region_type;
@@ -977,6 +985,7 @@
    }

if (biosdir2) {
+		assert_fw_entry(count, MAX_BIOS_ENTRIES, ctx);
    	biosdir->entries[count].type = AMD_BIOS_L2_PTR;
    	biosdir->entries[count].region_type = 0;
    	biosdir->entries[count].size =
@@ -994,13 +1003,6 @@
    	count++;
    }

-	if (count > MAX_BIOS_ENTRIES) {
-		fprintf(stderr, "Error: BIOS entries (%d) exceeds max allowed items "
-			"(%d)\n", count, MAX_BIOS_ENTRIES);
-		free(ctx->rom);
-		exit(1);
-	}
-
    fill_dir_header(biosdir, count, cookie, ctx);
 }