* [PATCH] ARM/hw_breakpoint: Mark expected switch fall-throughs
@ 2019-07-28 23:16 Gustavo A. R. Silva
2019-07-29 16:34 ` Kees Cook
0 siblings, 1 reply; 2+ messages in thread
From: Gustavo A. R. Silva @ 2019-07-28 23:16 UTC (permalink / raw)
To: Will Deacon, Mark Rutland, Russell King
Cc: Kees Cook, Stephen Rothwell, linux-kernel, linux-arm-kernel,
Gustavo A. R. Silva
Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings:
arch/arm/kernel/hw_breakpoint.c: In function 'hw_breakpoint_arch_parse':
arch/arm/kernel/hw_breakpoint.c:609:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
^
arch/arm/kernel/hw_breakpoint.c:611:2: note: here
case 3:
^~~~
arch/arm/kernel/hw_breakpoint.c:613:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
^
arch/arm/kernel/hw_breakpoint.c:615:2: note: here
default:
^~~~~~~
arch/arm/kernel/hw_breakpoint.c: In function 'arch_build_bp_info':
arch/arm/kernel/hw_breakpoint.c:544:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if ((hw->ctrl.type != ARM_BREAKPOINT_EXECUTE)
^
arch/arm/kernel/hw_breakpoint.c:547:2: note: here
default:
^~~~~~~
In file included from include/linux/kernel.h:11,
from include/linux/list.h:9,
from include/linux/preempt.h:11,
from include/linux/hardirq.h:5,
from arch/arm/kernel/hw_breakpoint.c:16:
arch/arm/kernel/hw_breakpoint.c: In function 'hw_breakpoint_pending':
include/linux/compiler.h:78:22: warning: this statement may fall through [-Wimplicit-fallthrough=]
# define unlikely(x) __builtin_expect(!!(x), 0)
^~~~~~~~~~~~~~~~~~~~~~~~~~
include/asm-generic/bug.h:136:2: note: in expansion of macro 'unlikely'
unlikely(__ret_warn_on); \
^~~~~~~~
arch/arm/kernel/hw_breakpoint.c:863:3: note: in expansion of macro 'WARN'
WARN(1, "Asynchronous watchpoint exception taken. Debugging results may be unreliable\n");
^~~~
arch/arm/kernel/hw_breakpoint.c:864:2: note: here
case ARM_ENTRY_SYNC_WATCHPOINT:
^~~~
arch/arm/kernel/hw_breakpoint.c: In function 'core_has_os_save_restore':
arch/arm/kernel/hw_breakpoint.c:910:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (oslsr & ARM_OSLSR_OSLM0)
^
arch/arm/kernel/hw_breakpoint.c:912:2: note: here
default:
^~~~~~~
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
arch/arm/kernel/hw_breakpoint.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index af8b8e15f589..b0c195e3a06d 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -544,6 +544,7 @@ static int arch_build_bp_info(struct perf_event *bp,
if ((hw->ctrl.type != ARM_BREAKPOINT_EXECUTE)
&& max_watchpoint_len >= 8)
break;
+ /* Else, fall through */
default:
return -EINVAL;
}
@@ -608,10 +609,12 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
/* Allow halfword watchpoints and breakpoints. */
if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
break;
+ /* Else, fall through */
case 3:
/* Allow single byte watchpoint. */
if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
break;
+ /* Else, fall through */
default:
ret = -EINVAL;
goto out;
@@ -861,6 +864,7 @@ static int hw_breakpoint_pending(unsigned long addr, unsigned int fsr,
break;
case ARM_ENTRY_ASYNC_WATCHPOINT:
WARN(1, "Asynchronous watchpoint exception taken. Debugging results may be unreliable\n");
+ /* Fall through */
case ARM_ENTRY_SYNC_WATCHPOINT:
watchpoint_handler(addr, fsr, regs);
break;
@@ -909,6 +913,7 @@ static bool core_has_os_save_restore(void)
ARM_DBG_READ(c1, c1, 4, oslsr);
if (oslsr & ARM_OSLSR_OSLM0)
return true;
+ /* Else, fall through */
default:
return false;
}
--
2.22.0
_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] ARM/hw_breakpoint: Mark expected switch fall-throughs
2019-07-28 23:16 [PATCH] ARM/hw_breakpoint: Mark expected switch fall-throughs Gustavo A. R. Silva
@ 2019-07-29 16:34 ` Kees Cook
0 siblings, 0 replies; 2+ messages in thread
From: Kees Cook @ 2019-07-29 16:34 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Mark Rutland, Stephen Rothwell, Russell King, linux-kernel,
Will Deacon, linux-arm-kernel
On Sun, Jul 28, 2019 at 06:16:51PM -0500, Gustavo A. R. Silva wrote:
> Mark switch cases where we are expecting to fall through.
>
> This patch fixes the following warnings:
>
> arch/arm/kernel/hw_breakpoint.c: In function 'hw_breakpoint_arch_parse':
> arch/arm/kernel/hw_breakpoint.c:609:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
> if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
> ^
> arch/arm/kernel/hw_breakpoint.c:611:2: note: here
> case 3:
> ^~~~
> arch/arm/kernel/hw_breakpoint.c:613:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
> if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
> ^
> arch/arm/kernel/hw_breakpoint.c:615:2: note: here
> default:
> ^~~~~~~
> arch/arm/kernel/hw_breakpoint.c: In function 'arch_build_bp_info':
> arch/arm/kernel/hw_breakpoint.c:544:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
> if ((hw->ctrl.type != ARM_BREAKPOINT_EXECUTE)
> ^
> arch/arm/kernel/hw_breakpoint.c:547:2: note: here
> default:
> ^~~~~~~
> In file included from include/linux/kernel.h:11,
> from include/linux/list.h:9,
> from include/linux/preempt.h:11,
> from include/linux/hardirq.h:5,
> from arch/arm/kernel/hw_breakpoint.c:16:
> arch/arm/kernel/hw_breakpoint.c: In function 'hw_breakpoint_pending':
> include/linux/compiler.h:78:22: warning: this statement may fall through [-Wimplicit-fallthrough=]
> # define unlikely(x) __builtin_expect(!!(x), 0)
> ^~~~~~~~~~~~~~~~~~~~~~~~~~
> include/asm-generic/bug.h:136:2: note: in expansion of macro 'unlikely'
> unlikely(__ret_warn_on); \
> ^~~~~~~~
> arch/arm/kernel/hw_breakpoint.c:863:3: note: in expansion of macro 'WARN'
> WARN(1, "Asynchronous watchpoint exception taken. Debugging results may be unreliable\n");
> ^~~~
> arch/arm/kernel/hw_breakpoint.c:864:2: note: here
> case ARM_ENTRY_SYNC_WATCHPOINT:
> ^~~~
> arch/arm/kernel/hw_breakpoint.c: In function 'core_has_os_save_restore':
> arch/arm/kernel/hw_breakpoint.c:910:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
> if (oslsr & ARM_OSLSR_OSLM0)
> ^
> arch/arm/kernel/hw_breakpoint.c:912:2: note: here
> default:
> ^~~~~~~
>
> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
-Kees
> ---
> arch/arm/kernel/hw_breakpoint.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
> index af8b8e15f589..b0c195e3a06d 100644
> --- a/arch/arm/kernel/hw_breakpoint.c
> +++ b/arch/arm/kernel/hw_breakpoint.c
> @@ -544,6 +544,7 @@ static int arch_build_bp_info(struct perf_event *bp,
> if ((hw->ctrl.type != ARM_BREAKPOINT_EXECUTE)
> && max_watchpoint_len >= 8)
> break;
> + /* Else, fall through */
> default:
> return -EINVAL;
> }
> @@ -608,10 +609,12 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
> /* Allow halfword watchpoints and breakpoints. */
> if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
> break;
> + /* Else, fall through */
> case 3:
> /* Allow single byte watchpoint. */
> if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
> break;
> + /* Else, fall through */
> default:
> ret = -EINVAL;
> goto out;
> @@ -861,6 +864,7 @@ static int hw_breakpoint_pending(unsigned long addr, unsigned int fsr,
> break;
> case ARM_ENTRY_ASYNC_WATCHPOINT:
> WARN(1, "Asynchronous watchpoint exception taken. Debugging results may be unreliable\n");
> + /* Fall through */
> case ARM_ENTRY_SYNC_WATCHPOINT:
> watchpoint_handler(addr, fsr, regs);
> break;
> @@ -909,6 +913,7 @@ static bool core_has_os_save_restore(void)
> ARM_DBG_READ(c1, c1, 4, oslsr);
> if (oslsr & ARM_OSLSR_OSLM0)
> return true;
> + /* Else, fall through */
> default:
> return false;
> }
> --
> 2.22.0
>
--
Kees Cook
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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