2023-09-23 02:51:07

by Kees Cook

Subject: [PATCH] x86/platform/uv: Annotate struct uv_rtc_timer_head with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct uv_rtc_timer_head.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Steve Wahl <[email protected]>
Cc: Mike Travis <[email protected]>
Cc: Dimitri Sivanich <[email protected]>
Cc: Russ Anderson <[email protected]>
Cc: Darren Hart <[email protected]>
Cc: Andy Shevchenko <[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]
Cc: "H. Peter Anvin" <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
arch/x86/platform/uv/uv_time.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/platform/uv/uv_time.c b/arch/x86/platform/uv/uv_time.c
index 54663f3e00cb..ff5afc8a5a41 100644
--- a/arch/x86/platform/uv/uv_time.c
+++ b/arch/x86/platform/uv/uv_time.c
@@ -53,7 +53,7 @@ struct uv_rtc_timer_head {
struct {
int lcpu; /* systemwide logical cpu number */
u64 expires; /* next timer expiration for this cpu */
- } cpu[];
+ } cpu[] __counted_by(ncpus);
};

/*
--
2.34.1

2023-09-23 17:43:04

by Gustavo A. R. Silva

Subject: Re: [PATCH] x86/platform/uv: Annotate struct uv_rtc_timer_head with __counted_by

On 9/22/23 11:51, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct uv_rtc_timer_head.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Steve Wahl <[email protected]>
> Cc: Mike Travis <[email protected]>
> Cc: Dimitri Sivanich <[email protected]>
> Cc: Russ Anderson <[email protected]>
> Cc: Darren Hart <[email protected]>
> Cc: Andy Shevchenko <[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]
> Cc: "H. Peter Anvin" <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

Reviewed-by: Gustavo A. R. Silva <[email protected]>

Thanks
--
Gustavo

> ---
> arch/x86/platform/uv/uv_time.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/platform/uv/uv_time.c b/arch/x86/platform/uv/uv_time.c
> index 54663f3e00cb..ff5afc8a5a41 100644
> --- a/arch/x86/platform/uv/uv_time.c
> +++ b/arch/x86/platform/uv/uv_time.c
> @@ -53,7 +53,7 @@ struct uv_rtc_timer_head {
> struct {
> int lcpu; /* systemwide logical cpu number */
> u64 expires; /* next timer expiration for this cpu */
> - } cpu[];
> + } cpu[] __counted_by(ncpus);
> };
>
> /*

2023-09-24 17:20:33

by tip-bot2 for Jacob Pan

Subject: [tip: x86/platform] x86/platform/uv: Annotate struct uv_rtc_timer_head with __counted_by

The following commit has been merged into the x86/platform branch of tip:

Commit-ID: d9a01959d9c954c8fe1d132b52401b0e219e37f6
Gitweb: https://git.kernel.org/tip/d9a01959d9c954c8fe1d132b52401b0e219e37f6
Author: Kees Cook <[email protected]>
AuthorDate: Fri, 22 Sep 2023 10:51:51 -07:00
Committer: Ingo Molnar <[email protected]>
CommitterDate: Sun, 24 Sep 2023 12:02:58 +02:00

x86/platform/uv: Annotate struct uv_rtc_timer_head with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

Found with Coccinelle:

https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Add __counted_by for struct uv_rtc_timer_head.

Signed-off-by: Kees Cook <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Reviewed-by: Gustavo A. R. Silva <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
arch/x86/platform/uv/uv_time.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/platform/uv/uv_time.c b/arch/x86/platform/uv/uv_time.c
index 54663f3..ff5afc8 100644
--- a/arch/x86/platform/uv/uv_time.c
+++ b/arch/x86/platform/uv/uv_time.c
@@ -53,7 +53,7 @@ struct uv_rtc_timer_head {
struct {
int lcpu; /* systemwide logical cpu number */
u64 expires; /* next timer expiration for this cpu */
- } cpu[];
+ } cpu[] __counted_by(ncpus);
};

/*

2023-09-29 00:12:20

by Steve Wahl

Subject: Re: [PATCH] x86/platform/uv: Annotate struct uv_rtc_timer_head with __counted_by

On Fri, Sep 22, 2023 at 10:51:51AM -0700, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct uv_rtc_timer_head.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Steve Wahl <[email protected]>
> Cc: Mike Travis <[email protected]>
> Cc: Dimitri Sivanich <[email protected]>
> Cc: Russ Anderson <[email protected]>
> Cc: Darren Hart <[email protected]>
> Cc: Andy Shevchenko <[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]
> Cc: "H. Peter Anvin" <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
>
> ---
> arch/x86/platform/uv/uv_time.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/platform/uv/uv_time.c b/arch/x86/platform/uv/uv_time.c
> index 54663f3e00cb..ff5afc8a5a41 100644
> --- a/arch/x86/platform/uv/uv_time.c
> +++ b/arch/x86/platform/uv/uv_time.c
> @@ -53,7 +53,7 @@ struct uv_rtc_timer_head {
> struct {
> int lcpu; /* systemwide logical cpu number */
> u64 expires; /* next timer expiration for this cpu */
> - } cpu[];
> + } cpu[] __counted_by(ncpus);
> };
>
> /*
> --
> 2.34.1

Looks good, thanks.

Reviewed-by: Steve Wahl <[email protected]>



--
Steve Wahl, Hewlett Packard Enterprise