linux/arch/x86/kernel/audit_64.c
Justin Stitt e8f13e061d x86/audit: Fix -Wmissing-variable-declarations warning for ia32_xyz_class
When building x86 defconfig with Clang-18 I get the following warnings:

  | arch/x86/ia32/audit.c:6:10: warning: no previous extern declaration for non-static variable 'ia32_dir_class' [-Wmissing-variable-declarations]
  |     6 | unsigned ia32_dir_class[] = {
  | arch/x86/ia32/audit.c:11:10: warning: no previous extern declaration for non-static variable 'ia32_chattr_class' [-Wmissing-variable-declarations]
  |    11 | unsigned ia32_chattr_class[] = {
  | arch/x86/ia32/audit.c:16:10: warning: no previous extern declaration for non-static variable 'ia32_write_class' [-Wmissing-variable-declarations]
  |    16 | unsigned ia32_write_class[] = {
  | arch/x86/ia32/audit.c:21:10: warning: no previous extern declaration for non-static variable 'ia32_read_class' [-Wmissing-variable-declarations]
  |    21 | unsigned ia32_read_class[] = {
  | arch/x86/ia32/audit.c:26:10: warning: no previous extern declaration for non-static variable 'ia32_signal_class' [-Wmissing-variable-declarations]
  |    26 | unsigned ia32_signal_class[] = {

These warnings occur due to their respective extern declarations being
scoped inside of audit_classes_init as well as only being enabled with
`CONFIG_IA32_EMULATION=y`:

  | static int __init audit_classes_init(void)
  | {
  | #ifdef CONFIG_IA32_EMULATION
  |	extern __u32 ia32_dir_class[];
  |	extern __u32 ia32_write_class[];
  |	extern __u32 ia32_read_class[];
  |	extern __u32 ia32_chattr_class[];
  |	audit_register_class(AUDIT_CLASS_WRITE_32, ia32_write_class);
  |	audit_register_class(AUDIT_CLASS_READ_32, ia32_read_class);
  |	audit_register_class(AUDIT_CLASS_DIR_WRITE_32, ia32_dir_class);
  |	audit_register_class(AUDIT_CLASS_CHATTR_32, ia32_chattr_class);
  | #endif
  |	audit_register_class(AUDIT_CLASS_WRITE, write_class);
  |	audit_register_class(AUDIT_CLASS_READ, read_class);
  |	audit_register_class(AUDIT_CLASS_DIR_WRITE, dir_class);
  |	audit_register_class(AUDIT_CLASS_CHATTR, chattr_class);
  |	return 0;
  | }

Lift the extern declarations to their own header and resolve scoping
issues (and thus fix the warnings).

Moreover, change __u32 to unsigned so that we match the definitions:

  | unsigned ia32_dir_class[] = {
  | #include <asm-generic/audit_dir_write.h>
  | ~0U
  | };
  |
  | unsigned ia32_chattr_class[] = {
  | #include <asm-generic/audit_change_attr.h>
  | ~0U
  | };
  | ...

This patch is similar to commit:

  0e5e3d4461 ("x86/audit: Fix a -Wmissing-prototypes warning for ia32_classify_syscall()") [1]

Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/all/20200516123816.2680-1-b.thiel@posteo.de/ [1]
Link: https://github.com/ClangBuiltLinux/linux/issues/1920
Link: https://lore.kernel.org/r/20230829-missingvardecl-audit-v1-1-34efeb7f3539@google.com
2023-08-30 10:11:16 +02:00

81 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/init.h>
#include <linux/types.h>
#include <linux/audit.h>
#include <asm/unistd.h>
#include <asm/audit.h>
static unsigned dir_class[] = {
#include <asm-generic/audit_dir_write.h>
~0U
};
static unsigned read_class[] = {
#include <asm-generic/audit_read.h>
~0U
};
static unsigned write_class[] = {
#include <asm-generic/audit_write.h>
~0U
};
static unsigned chattr_class[] = {
#include <asm-generic/audit_change_attr.h>
~0U
};
static unsigned signal_class[] = {
#include <asm-generic/audit_signal.h>
~0U
};
int audit_classify_arch(int arch)
{
#ifdef CONFIG_IA32_EMULATION
if (arch == AUDIT_ARCH_I386)
return 1;
#endif
return 0;
}
int audit_classify_syscall(int abi, unsigned syscall)
{
#ifdef CONFIG_IA32_EMULATION
if (abi == AUDIT_ARCH_I386)
return ia32_classify_syscall(syscall);
#endif
switch(syscall) {
case __NR_open:
return AUDITSC_OPEN;
case __NR_openat:
return AUDITSC_OPENAT;
case __NR_execve:
case __NR_execveat:
return AUDITSC_EXECVE;
case __NR_openat2:
return AUDITSC_OPENAT2;
default:
return AUDITSC_NATIVE;
}
}
static int __init audit_classes_init(void)
{
#ifdef CONFIG_IA32_EMULATION
audit_register_class(AUDIT_CLASS_WRITE_32, ia32_write_class);
audit_register_class(AUDIT_CLASS_READ_32, ia32_read_class);
audit_register_class(AUDIT_CLASS_DIR_WRITE_32, ia32_dir_class);
audit_register_class(AUDIT_CLASS_CHATTR_32, ia32_chattr_class);
audit_register_class(AUDIT_CLASS_SIGNAL_32, ia32_signal_class);
#endif
audit_register_class(AUDIT_CLASS_WRITE, write_class);
audit_register_class(AUDIT_CLASS_READ, read_class);
audit_register_class(AUDIT_CLASS_DIR_WRITE, dir_class);
audit_register_class(AUDIT_CLASS_CHATTR, chattr_class);
audit_register_class(AUDIT_CLASS_SIGNAL, signal_class);
return 0;
}
__initcall(audit_classes_init);