From: Tiezhu Yang Date: Mon, 16 Mar 2026 02:36:01 +0000 (+0800) Subject: LoongArch: Give more information if kmem access failed X-Git-Tag: v7.0-rc5~38^2~4 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a47f0754bdd01f971c9715acdbdd3a07515c8f83;p=thirdparty%2Fkernel%2Flinux.git LoongArch: Give more information if kmem access failed If memory access such as copy_{from, to}_kernel_nofault() failed, its users do not know what happened, so it is very useful to print the exception code for such cases. Furthermore, it is better to print the caller function to know where is the entry. Here are the low level call chains: copy_from_kernel_nofault() copy_from_kernel_nofault_loop() __get_kernel_nofault() copy_to_kernel_nofault() copy_to_kernel_nofault_loop() __put_kernel_nofault() Cc: stable@vger.kernel.org Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen --- diff --git a/arch/loongarch/include/asm/uaccess.h b/arch/loongarch/include/asm/uaccess.h index 4e259d490e45..438269313e78 100644 --- a/arch/loongarch/include/asm/uaccess.h +++ b/arch/loongarch/include/asm/uaccess.h @@ -253,8 +253,13 @@ do { \ \ __get_kernel_common(*((type *)(dst)), sizeof(type), \ (__force type *)(src)); \ - if (unlikely(__gu_err)) \ + if (unlikely(__gu_err)) { \ + pr_info("%s: memory access failed, ecode 0x%x\n", \ + __func__, read_csr_excode()); \ + pr_info("%s: the caller is %pS\n", \ + __func__, __builtin_return_address(0)); \ goto err_label; \ + } \ } while (0) #define __put_kernel_nofault(dst, src, type, err_label) \ @@ -264,8 +269,13 @@ do { \ \ __pu_val = *(__force type *)(src); \ __put_kernel_common(((type *)(dst)), sizeof(type)); \ - if (unlikely(__pu_err)) \ + if (unlikely(__pu_err)) { \ + pr_info("%s: memory access failed, ecode 0x%x\n", \ + __func__, read_csr_excode()); \ + pr_info("%s: the caller is %pS\n", \ + __func__, __builtin_return_address(0)); \ goto err_label; \ + } \ } while (0) extern unsigned long __copy_user(void *to, const void *from, __kernel_size_t n);