linux-kernel - [PATCH] scripts: Enhance vmlinux checks as per TODO

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Message-Id: <20240811125218.45759-1-jain.abhinav177@gmail.com>
Date: Sun, 11 Aug 2024 12:52:18 +0000
From: Abhinav Jain <jain.abhinav177@...il.com>
To: masahiroy@...nel.org,
	nathan@...nel.org,
	nicolas@...sle.eu,
	linux-kbuild@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc: skhan@...uxfoundation.org,
	javier.carrasco.cruz@...il.com,
	Abhinav Jain <jain.abhinav177@...il.com>
Subject: [PATCH] scripts: Enhance vmlinux checks as per TODO

Add checks for ELF validity, critical sections, symbols and static
linkage.
Zero warnings/errors as per scripts/checkpatch.pl for this patch.

Signed-off-by: Abhinav Jain <jain.abhinav177@...il.com>
---
 scripts/extract-vmlinux | 68 ++++++++++++++++++++++++++++++++++++++---
 1 file changed, 63 insertions(+), 5 deletions(-)

diff --git a/scripts/extract-vmlinux b/scripts/extract-vmlinux
index 8995cd304e6e..2c35dde8a8ce 100755
--- a/scripts/extract-vmlinux
+++ b/scripts/extract-vmlinux
@@ -12,12 +12,70 @@
 
 check_vmlinux()
 {
-	# Use readelf to check if it's a valid ELF
-	# TODO: find a better to way to check that it's really vmlinux
-	#       and not just an elf
-	readelf -h $1 > /dev/null 2>&1 || return 1
+	# Use readelf/nm to check if it's a valid ELF
+	# Check for valid ELF, critical sections, symbols, static linking
 
-	cat $1
+	# Check if the file is a valid ELF file
+	if ! readelf -h "$file" > /dev/null 2>&1; then
+		echo "Error: File is not a valid ELF file."
+		return 1
+	fi
+
+	# Check the ELF type (should be ET_EXEC for executable)
+	if ! readelf -h "$file" | grep -q "Type:\s*EXEC (Executable file)"; then
+		echo "Error: ELF file is not an executable type."
+		return 1
+	fi
+
+	# Check for the presence of key kernel sections
+	if ! readelf -S "$file" | grep -q '\.text'; then
+		echo "Error: File does not contain a .text section, not a valid vmlinux file."
+		return 1
+	fi
+
+	if ! readelf -S "$file" | grep -q '\.data'; then
+		echo "Error: File does not contain a .data section, not a valid vmlinux file."
+		return 1
+	fi
+
+	if ! readelf -S "$file" | grep -q '\.bss'; then
+		echo "Error: File does not contain a .bss section, not a valid vmlinux file."
+		return 1
+	fi
+
+	if ! readelf -S "$file" | grep -q '\.rodata'; then
+		echo "Error: File does not contain a .rodata section, not a valid vmlinux file."
+		return 1
+	fi
+
+	# Check for the presence of key kernel symbols
+	if ! nm "$file" | grep -q ' T start_kernel'; then
+		echo "Error: File does not contain the start_kernel symbol, not a valid vmlinux file."
+		return 1
+	fi
+
+	if ! nm "$file" | grep -q ' T _stext'; then
+		echo "Error: File does not contain the _stext symbol, not a valid vmlinux file."
+		return 1
+	fi
+
+	if ! nm "$file" | grep -q ' D _sdata'; then
+		echo "Error: File does not contain the _sdata symbol, not a valid vmlinux file."
+		return 1
+	fi
+
+	if ! nm "$file" | grep -q ' B __bss_start'; then
+		echo "Error: File does not contain the __bss_start symbol, not a valid vmlinux file."
+		return 1
+	fi
+
+	# Check for the absence of dynamic linking sections
+	if readelf -d "$file" 2>/dev/null | grep -q 'Shared library'; then
+		echo "Error: File contains dynamic linking information, not a valid vmlinux file."
+		return 1
+	fi
+
+	echo "File is a valid vmlinux file."
 	exit 0
 }
 
-- 
2.34.1