Under W=1, this warning is visible in Clang 16 and newer:
arch/x86/kernel/paravirt.c:337:4: warning: cast from 'void (*)(struct mmu_gather *, struct page *)' to 'void (*)(struct mmu_gather *, void *)' converts to incompatible function type [-Wcast-function-type-strict]
(void (*)(struct mmu_gather *, void *))tlb_remove_page,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Add a direct wrapper instead, which will make this warning (and
potential KCFI failures) go away.
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Cc: Juergen Gross <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sami Tolvanen <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Ajay Kaher <[email protected]>
Cc: Alexey Makhalov <[email protected]>
Cc: VMware PV-Drivers Reviewers <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
arch/x86/kernel/paravirt.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index ac10b46c5832..23d4d7114473 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -79,6 +79,11 @@ void __init native_pv_lock_init(void)
static_branch_disable(&virt_spin_lock_key);
}
+static void native_tlb_remove_table(struct mmu_gather *tlb, void *table)
+{
+ tlb_remove_page(tlb, table);
+}
+
unsigned int paravirt_patch(u8 type, void *insn_buff, unsigned long addr,
unsigned int len)
{
@@ -295,8 +300,7 @@ struct paravirt_patch_template pv_ops = {
.mmu.flush_tlb_kernel = native_flush_tlb_global,
.mmu.flush_tlb_one_user = native_flush_tlb_one_user,
.mmu.flush_tlb_multi = native_flush_tlb_multi,
- .mmu.tlb_remove_table =
- (void (*)(struct mmu_gather *, void *))tlb_remove_page,
+ .mmu.tlb_remove_table = native_tlb_remove_table,
.mmu.exit_mmap = paravirt_nop,
.mmu.notify_page_enc_status_changed = paravirt_nop,
--
2.34.1
On 27.07.23 01:11, Kees Cook wrote:
> Under W=1, this warning is visible in Clang 16 and newer:
>
> arch/x86/kernel/paravirt.c:337:4: warning: cast from 'void (*)(struct mmu_gather *, struct page *)' to 'void (*)(struct mmu_gather *, void *)' converts to incompatible function type [-Wcast-function-type-strict]
> (void (*)(struct mmu_gather *, void *))tlb_remove_page,
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Add a direct wrapper instead, which will make this warning (and
> potential KCFI failures) go away.
>
> Reported-by: kernel test robot <[email protected]>
> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> Cc: Juergen Gross <[email protected]>
> Cc: Peter Zijlstra <[email protected]>
> Cc: Sami Tolvanen <[email protected]>
> Cc: Nathan Chancellor <[email protected]>
> Cc: Ajay Kaher <[email protected]>
> Cc: Alexey Makhalov <[email protected]>
> Cc: VMware PV-Drivers Reviewers <[email protected]>
> Cc: Thomas Gleixner <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> Cc: Borislav Petkov <[email protected]>
> Cc: Dave Hansen <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Juergen Gross <[email protected]>
Juergen
On Wed, 26 Jul 2023 16:11:43 -0700, Kees Cook wrote:
> Under W=1, this warning is visible in Clang 16 and newer:
>
> arch/x86/kernel/paravirt.c:337:4: warning: cast from 'void (*)(struct mmu_gather *, struct page *)' to 'void (*)(struct mmu_gather *, void *)' converts to incompatible function type [-Wcast-function-type-strict]
> (void (*)(struct mmu_gather *, void *))tlb_remove_page,
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Add a direct wrapper instead, which will make this warning (and
> potential KCFI failures) go away.
>
> [...]
Applied to for-next/hardening, thanks!
[1/1] x86/paravirt: Fix tlb_remove_table function callback prototype warning
https://git.kernel.org/kees/c/fcce1c6cb156
Take care,
--
Kees Cook