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From: Charlie Jenkins <charlie@rivosinc.com>
Date: Wed, 03 Jan 2024 12:22:03 -0800
Subject: [PATCH v2 4/4] riscv: Convert relocation iterator to do-while
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Message-Id: <20240103-module_loading_fix-v2-4-292b160552c9@rivosinc.com>
References: <20240103-module_loading_fix-v2-0-292b160552c9@rivosinc.com>
In-Reply-To: <20240103-module_loading_fix-v2-0-292b160552c9@rivosinc.com>
To: Paul Walmsley <paul.walmsley@sifive.com>, 
 Palmer Dabbelt <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu>
Cc: Palmer Dabbelt <palmer@rivosinc.com>, linux-riscv@lists.infradead.org, 
 linux-kernel@vger.kernel.org, Charlie Jenkins <charlie@rivosinc.com>, 
 kernel test robot <lkp@intel.com>, Dan Carpenter <error27@gmail.com>

Use a do-while loop to iterate through relocation entries to prevent
curr_type from being marked as uninitialized.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Fixes: d8792a5734b0 ("riscv: Safely remove entries from relocation list")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/r/202312130859.wnkuzVWY-lkp@intel.com/
---
 arch/riscv/kernel/module.c | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
index ceb0adb38715..581e425686ab 100644
--- a/arch/riscv/kernel/module.c
+++ b/arch/riscv/kernel/module.c
@@ -633,15 +633,31 @@ process_accumulated_relocations(struct module *me,
 					  bucket_iter->bucket, node) {
 			buffer = 0;
 			location = rel_head_iter->location;
-			list_for_each_entry_safe(rel_entry_iter,
-						 rel_entry_iter_tmp,
-						 rel_head_iter->rel_entry,
-						 head) {
+			rel_entry_iter =
+				list_first_entry(rel_head_iter->rel_entry,
+						 typeof(*rel_entry_iter), head);
+			rel_entry_iter_tmp =
+				list_next_entry(rel_entry_iter, head);
+
+			/*
+			 * Iterate through all relocation entries that share
+			 * this location. This uses a do-while loop instead of
+			 * list_for_each_entry_safe since it is known that there
+			 * is at least one entry and curr_type needs to be the
+			 * value of the last entry when the loop exits.
+			 */
+			do {
 				curr_type = rel_entry_iter->type;
 				reloc_handlers[curr_type].reloc_handler(
 					me, &buffer, rel_entry_iter->value);
 				kfree(rel_entry_iter);
-			}
+
+				rel_entry_iter = rel_entry_iter_tmp;
+				rel_entry_iter_tmp = list_next_entry(rel_entry_iter_tmp, head);
+			} while (!list_entry_is_head(rel_entry_iter,
+						     rel_head_iter->rel_entry,
+						     head));
+
 			reloc_handlers[curr_type].accumulate_handler(
 				me, location, buffer);
 			kfree(rel_head_iter);

-- 
2.43.0