Re: [PATCH -tip] x86: acpi/sleep.c saved_magic fix overflow

From: Pavel Machek
Date: Fri Apr 10 2009 - 13:52:56 EST


On Fri 2009-04-10 23:06:55, Jaswinder Singh Rajput wrote:
> Impact: fix overflow

> Constant 0x123456789abcdef0 is so big for a long.
> So using saved_magic 0x12345678 for both 32 and 64 bit.

Have you tested the patch? I have feeling that this is tested from
assembly... Plus it is only set to long constant on 64-bit, so I don't
think you are fixing anything. And if your code is correct the
variable is write only...

> Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@xxxxxxxxx>

NAK.

Pavel
> ---
> arch/x86/kernel/acpi/sleep.c | 3 +--
> 1 files changed, 1 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
> index 7c243a2..1ad317a 100644
> --- a/arch/x86/kernel/acpi/sleep.c
> +++ b/arch/x86/kernel/acpi/sleep.c
> @@ -94,7 +94,6 @@ int acpi_save_state_mem(void)
> #ifndef CONFIG_64BIT
> header->pmode_entry = (u32)&wakeup_pmode_return;
> header->pmode_cr3 = (u32)(swsusp_pg_dir - __PAGE_OFFSET);
> - saved_magic = 0x12345678;
> #else /* CONFIG_64BIT */
> header->trampoline_segment = setup_trampoline() >> 4;
> #ifdef CONFIG_SMP
> @@ -104,8 +103,8 @@ int acpi_save_state_mem(void)
> initial_gs = per_cpu_offset(smp_processor_id());
> #endif
> initial_code = (unsigned long)wakeup_long64;
> - saved_magic = 0x123456789abcdef0;
> #endif /* CONFIG_64BIT */
> + saved_magic = 0x12345678;
>
> return 0;
> }

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