From 212f07a21622cbd4bb271b558b2d3ae0652e9875 Mon Sep 17 00:00:00 2001 From: Justin Stitt Date: Tue, 22 Aug 2023 22:05:30 +0000 Subject: x86/platform/uv: Refactor code using deprecated strncpy() interface to use strscpy() `strncpy` is deprecated for use on NUL-terminated destination strings [1]. A suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on its destination buffer argument which is _not_ the case for `strncpy`! In this case, it means we can drop the `...-1` from: | strncpy(to, from, len-1); as well as remove the comment mentioning NUL-termination as `strscpy` implicitly grants us this behavior. There should be no functional change as I don't believe the padding from `strncpy` is needed here. If it turns out that the padding is necessary we should use `strscpy_pad` as a direct replacement. Signed-off-by: Justin Stitt Signed-off-by: Ingo Molnar Cc: Andy Shevchenko Cc: Kees Cook Cc: Dimitri Sivanich Link: www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings[1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Link: https://lore.kernel.org/r/20230822-strncpy-arch-x86-kernel-apic-x2apic_uv_x-v1-1-91d681d0b3f3@google.com --- arch/x86/kernel/apic/x2apic_uv_x.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'arch/x86/kernel/apic/x2apic_uv_x.c') diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c index d9384d5b4b8e..b524dee1cbbb 100644 --- a/arch/x86/kernel/apic/x2apic_uv_x.c +++ b/arch/x86/kernel/apic/x2apic_uv_x.c @@ -294,8 +294,7 @@ static void __init early_get_apic_socketid_shift(void) static void __init uv_stringify(int len, char *to, char *from) { - /* Relies on 'to' being NULL chars so result will be NULL terminated */ - strncpy(to, from, len-1); + strscpy(to, from, len); /* Trim trailing spaces */ (void)strim(to); @@ -1013,7 +1012,7 @@ static void __init calc_mmioh_map(enum mmioh_arch index, /* One (UV2) mapping */ if (index == UV2_MMIOH) { - strncpy(id, "MMIOH", sizeof(id)); + strscpy(id, "MMIOH", sizeof(id)); max_io = max_pnode; mapped = 0; goto map_exit; -- cgit