[RFC PATCH v1 3/9] x86/umip: Be stricter in fixup_umip_exception()

Christophe Leroy (CS GROUP)
2026-04-27T17:17:55Z

fixup_umip_exception() calls copy_to_user() and checks whether
the returned value is strictly positive.

A subsequent patch will change the return of copy_to_user() to
return -EFAULT in case of error.

Change the test to checking that the result is not 0.

At the time being copy_to_user() return an unsigned value so
'strictly positive' is the same as 'not 0'.

Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
---
arch/x86/kernel/umip.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c
index 3ce99cbcf187..dfff28ea1dea 100644
--- a/arch/x86/kernel/umip.c
+++ b/arch/x86/kernel/umip.c
@@ -409,7 +409,7 @@ bool fixup_umip_exception(struct pt_regs *regs)
return false;

nr_copied = copy_to_user(uaddr, dummy_data, dummy_data_size);
- if (nr_copied > 0) {
+ if (nr_copied) {
/*
* If copy fails, send a signal and tell caller that
* fault was fixed up.
--
2.49.0