linux-kernel - [PATCH v2] kernel/module: add name size info to pr

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Message-Id: <20200630170903.1320459-1-jim.cromie@gmail.com>
Date:   Tue, 30 Jun 2020 11:09:03 -0600
From:   Jim Cromie <jim.cromie@...il.com>
To:     Jessica Yu <jeyu@...nel.org>, linux-kernel@...r.kernel.org
Cc:     Jim Cromie <jim.cromie@...il.com>
Subject: [PATCH v2] kernel/module:  add name size info to pr_debug() calls

When the kernel is booted with arg: module.dyndbg=+p, dmesg gets
volumes of info about layout details of loaded modules.  This adds
module & symbol names to those messages, and sizes where pertinent.
Since these are debug messages, I thought sizes might be useful to
somebody, without adding clutter or or too much info.

Now a reader can know which module's info they're looking at, or which
2 modules they are comparing.

--
v2 has:
better commit message
s/:%s/%s:/
s/final/Final/

Signed-off-by: Jim Cromie <jim.cromie@...il.com>
---
 kernel/module.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/kernel/module.c b/kernel/module.c
index 0c6573b98c36..809490145b77 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2294,8 +2294,8 @@ static int simplify_symbols(struct module *mod, const struct load_info *info)
 
 		case SHN_ABS:
 			/* Don't need to do anything */
-			pr_debug("Absolute symbol: 0x%08lx\n",
-			       (long)sym[i].st_value);
+			pr_debug("Absolute symbol: 0x%08lx %s\n",
+				 (long)sym[i].st_value, name);
 			break;
 
 		case SHN_LIVEPATCH:
@@ -2409,7 +2409,7 @@ static void layout_sections(struct module *mod, struct load_info *info)
 	for (i = 0; i < info->hdr->e_shnum; i++)
 		info->sechdrs[i].sh_entsize = ~0UL;
 
-	pr_debug("Core section allocation order:\n");
+	pr_debug("Core section allocation order for %s:\n", mod->name);
 	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
 		for (i = 0; i < info->hdr->e_shnum; ++i) {
 			Elf_Shdr *s = &info->sechdrs[i];
@@ -2442,7 +2442,7 @@ static void layout_sections(struct module *mod, struct load_info *info)
 		}
 	}
 
-	pr_debug("Init section allocation order:\n");
+	pr_debug("Init section allocation order for %s:\n", mod->name);
 	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
 		for (i = 0; i < info->hdr->e_shnum; ++i) {
 			Elf_Shdr *s = &info->sechdrs[i];
@@ -3278,7 +3278,7 @@ static int move_module(struct module *mod, struct load_info *info)
 		mod->init_layout.base = NULL;
 
 	/* Transfer each section which specifies SHF_ALLOC */
-	pr_debug("final section addresses:\n");
+	pr_debug("Final section addresses for %s:\n", mod->name);
 	for (i = 0; i < info->hdr->e_shnum; i++) {
 		void *dest;
 		Elf_Shdr *shdr = &info->sechdrs[i];
@@ -3296,8 +3296,8 @@ static int move_module(struct module *mod, struct load_info *info)
 			memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
 		/* Update sh_addr to point to copy in image. */
 		shdr->sh_addr = (unsigned long)dest;
-		pr_debug("\t0x%lx %s\n",
-			 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
+		pr_debug("\t0x%lx 0x%.8lx %s\n", (long)shdr->sh_addr,
+			 (long)shdr->sh_size, info->secstrings + shdr->sh_name);
 	}
 
 	return 0;
-- 
2.26.2