From: Charlie Jenkins Date: Thu, 4 Jan 2024 19:42:48 +0000 (-0800) Subject: riscv: Correctly free relocation hashtable on error X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=4b38b36bfbd83b23e20c172d08dd85773791e3bd;p=linux.git 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: Charlie Jenkins Fixes: d8792a5734b0 ("riscv: Safely remove entries from relocation list") Reported-by: kernel test robot Reported-by: Dan Carpenter Closes: https://lore.kernel.org/r/202312132019.iYGTwW0L-lkp@intel.com/ Reported-by: kernel test robot Reported-by: Julia Lawall Closes: https://lore.kernel.org/r/202312120044.wTI1Uyaa-lkp@intel.com/ Reviewed-by: Dan Carpenter Link: https://lore.kernel.org/r/20240104-module_loading_fix-v3-2-a71f8de6ce0f@rivosinc.com Signed-off-by: Palmer Dabbelt --- diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c index 21c7a773a8efa..32743180e8ef5 100644 --- a/arch/riscv/kernel/module.c +++ b/arch/riscv/kernel/module.c @@ -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);