Unverified Commit 4b38b36b authored by Charlie Jenkins's avatar Charlie Jenkins Committed by Palmer Dabbelt
Browse files

riscv: Correctly free relocation hashtable on error 



When there is not enough allocatable memory for the relocation
hashtable, module loading should exit gracefully. Previously, this was
attempted to be accomplished by checking if an unsigned number is less
than zero which does not work. Instead have the caller check if the
hashtable was correctly allocated and add a comment explaining that
hashtable_bits that is 0 is valid.

Signed-off-by: default avatarCharlie Jenkins <charlie@rivosinc.com>
Fixes: d8792a57 ("riscv: Safely remove entries from relocation list")
Reported-by: default avatarkernel test robot <lkp@intel.com>
Reported-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202312132019.iYGTwW0L-lkp@intel.com/


Reported-by: default avatarkernel test robot <lkp@intel.com>
Reported-by: default avatarJulia Lawall <julia.lawall@inria.fr>
Closes: https://lore.kernel.org/r/202312120044.wTI1Uyaa-lkp@intel.com/


Reviewed-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20240104-module_loading_fix-v3-2-a71f8de6ce0f@rivosinc.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 78996eee

arch/riscv/kernel/module.c

+7 −3
Original line number Diff line number Diff line
@@ -747,6 +747,10 @@ initialize_relocation_hashtable(unsigned int num_relocations, 
{

	/* Can safely assume that bits is not greater than sizeof(long) */

	unsigned long hashtable_size = roundup_pow_of_two(num_relocations);

	/*

	 * When hashtable_size == 1, hashtable_bits == 0.

	 * This is valid because the hashing algorithm returns 0 in this case.

	 */

	unsigned int hashtable_bits = ilog2(hashtable_size);



	/*
@@ -763,7 +767,7 @@ initialize_relocation_hashtable(unsigned int num_relocations, 
					      sizeof(*relocation_hashtable),

					      GFP_KERNEL);

	if (!*relocation_hashtable)

		return -ENOMEM;

		return 0;



	__hash_init(*relocation_hashtable, hashtable_size);
@@ -789,8 +793,8 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, 
	hashtable_bits = initialize_relocation_hashtable(num_relocations,

							 &relocation_hashtable);



	if (hashtable_bits < 0)

		return hashtable_bits;

	if (!relocation_hashtable)

		return -ENOMEM;



	INIT_LIST_HEAD(&used_buckets_list);