2023-10-06 20:18:37

by Kees Cook

Subject: [PATCH] perf/x86/rapl: Annotate struct rapl_pmus 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 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 rapl_pmus.

Cc: Peter Zijlstra <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: [email protected]
Cc: "H. Peter Anvin" <[email protected]>
Cc: "Gustavo A. R. Silva" <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <[email protected]>
---
arch/x86/events/rapl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/rapl.c b/arch/x86/events/rapl.c
index c2c37fb0a228..8d98d468b976 100644
--- a/arch/x86/events/rapl.c
+++ b/arch/x86/events/rapl.c
@@ -115,7 +115,7 @@ struct rapl_pmu {
struct rapl_pmus {
struct pmu pmu;
unsigned int maxdie;
- struct rapl_pmu *pmus[];
+ struct rapl_pmu *pmus[] __counted_by(maxdie);
};

enum rapl_unit_quirk {
--
2.34.1

2023-10-06 20:47:09

by Gustavo A. R. Silva

Subject: Re: [PATCH] perf/x86/rapl: Annotate struct rapl_pmus with __counted_by

On 10/6/23 22:17, 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 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 rapl_pmus.
>
> Cc: Peter Zijlstra <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> Cc: Arnaldo Carvalho de Melo <[email protected]>
> Cc: Mark Rutland <[email protected]>
> Cc: Alexander Shishkin <[email protected]>
> Cc: Jiri Olsa <[email protected]>
> Cc: Namhyung Kim <[email protected]>
> Cc: Ian Rogers <[email protected]>
> Cc: Adrian Hunter <[email protected]>
> Cc: Thomas Gleixner <[email protected]>
> Cc: Borislav Petkov <[email protected]>
> Cc: Dave Hansen <[email protected]>
> Cc: [email protected]
> Cc: "H. Peter Anvin" <[email protected]>
> Cc: "Gustavo A. R. Silva" <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
> Signed-off-by: Kees Cook <[email protected]>

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

Thanks!
--
Gustavo

> ---
> arch/x86/events/rapl.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/events/rapl.c b/arch/x86/events/rapl.c
> index c2c37fb0a228..8d98d468b976 100644
> --- a/arch/x86/events/rapl.c
> +++ b/arch/x86/events/rapl.c
> @@ -115,7 +115,7 @@ struct rapl_pmu {
> struct rapl_pmus {
> struct pmu pmu;
> unsigned int maxdie;
> - struct rapl_pmu *pmus[];
> + struct rapl_pmu *pmus[] __counted_by(maxdie);
> };
>
> enum rapl_unit_quirk {

2023-10-08 10:22:46

by tip-bot2 for Jacob Pan

Subject: [tip: perf/core] perf/x86/rapl: Annotate 'struct rapl_pmus' with __counted_by

The following commit has been merged into the perf/core branch of tip:

Commit-ID: a56d5551e1993ca84dd0c69df5a3d8223d13fb5f
Gitweb: https://git.kernel.org/tip/a56d5551e1993ca84dd0c69df5a3d8223d13fb5f
Author: Kees Cook <[email protected]>
AuthorDate: Fri, 06 Oct 2023 13:17:54 -07:00
Committer: Ingo Molnar <[email protected]>
CommitterDate: Sun, 08 Oct 2023 12:18:17 +02:00

perf/x86/rapl: Annotate 'struct rapl_pmus' 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 via CONFIG_UBSAN_BOUNDS=y (for
array indexing) and CONFIG_FORTIFY_SOURCE=y (for strcpy/memcpy-family
functions).

Found with Coccinelle:

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

Add __counted_by for 'struct rapl_pmus'.

No change in functionality intended.

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/events/rapl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/rapl.c b/arch/x86/events/rapl.c
index c2c37fb..8d98d46 100644
--- a/arch/x86/events/rapl.c
+++ b/arch/x86/events/rapl.c
@@ -115,7 +115,7 @@ struct rapl_pmu {
struct rapl_pmus {
struct pmu pmu;
unsigned int maxdie;
- struct rapl_pmu *pmus[];
+ struct rapl_pmu *pmus[] __counted_by(maxdie);
};

enum rapl_unit_quirk {