Re: [PATCH] pstore/ram: fix undefined usage of rounddown_pow_of_two.
On Friday 19 October 2012 09:03:12 Kees Cook wrote: > On Fri, Oct 19, 2012 at 4:59 AM, Florian Fainelli > wrote: > > From: Maxime Bizon > > > > record_size / console_size / ftrace_size can be 0 (this is how you > > disable the feature), but rounddown_pow_of_two(0) is undefined. This problem > > has been present since commit 1894a253 (ramoops: Move to fs/pstore/ram.c). > > > > Signed-off-by: Maxime Bizon > > Signed-off-by: Florian Fainelli > > CC: sta...@vger.kernel.org > > --- > > fs/pstore/ram.c | 12 > > 1 file changed, 8 insertions(+), 4 deletions(-) > > > > diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c > > index 1a4f6da..0c2ae26 100644 > > --- a/fs/pstore/ram.c > > +++ b/fs/pstore/ram.c > > @@ -374,10 +374,14 @@ static int __devinit ramoops_probe(struct > > platform_device *pdev) > > goto fail_out; > > } > > > > - pdata->mem_size = rounddown_pow_of_two(pdata->mem_size); > > - pdata->record_size = rounddown_pow_of_two(pdata->record_size); > > - pdata->console_size = rounddown_pow_of_two(pdata->console_size); > > - pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size); > > + if (pdata->mem_size) > > + pdata->mem_size = rounddown_pow_of_two(pdata->mem_size); > > Nice catch! > > Instead of the == 0 check, what about using !is_power_of_2(size) ? That would work equally well, I will resubmit with this then. -- Florian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] pstore/ram: fix undefined usage of rounddown_pow_of_two.
On Fri, Oct 19, 2012 at 4:59 AM, Florian Fainelli wrote: > From: Maxime Bizon > > record_size / console_size / ftrace_size can be 0 (this is how you > disable the feature), but rounddown_pow_of_two(0) is undefined. This problem > has been present since commit 1894a253 (ramoops: Move to fs/pstore/ram.c). > > Signed-off-by: Maxime Bizon > Signed-off-by: Florian Fainelli > CC: sta...@vger.kernel.org > --- > fs/pstore/ram.c | 12 > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c > index 1a4f6da..0c2ae26 100644 > --- a/fs/pstore/ram.c > +++ b/fs/pstore/ram.c > @@ -374,10 +374,14 @@ static int __devinit ramoops_probe(struct > platform_device *pdev) > goto fail_out; > } > > - pdata->mem_size = rounddown_pow_of_two(pdata->mem_size); > - pdata->record_size = rounddown_pow_of_two(pdata->record_size); > - pdata->console_size = rounddown_pow_of_two(pdata->console_size); > - pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size); > + if (pdata->mem_size) > + pdata->mem_size = rounddown_pow_of_two(pdata->mem_size); Nice catch! Instead of the == 0 check, what about using !is_power_of_2(size) ? -Kees -- Kees Cook Chrome OS Security -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] pstore/ram: fix undefined usage of rounddown_pow_of_two.
From: Maxime Bizon record_size / console_size / ftrace_size can be 0 (this is how you disable the feature), but rounddown_pow_of_two(0) is undefined. This problem has been present since commit 1894a253 (ramoops: Move to fs/pstore/ram.c). Signed-off-by: Maxime Bizon Signed-off-by: Florian Fainelli CC: sta...@vger.kernel.org --- fs/pstore/ram.c | 12 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 1a4f6da..0c2ae26 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -374,10 +374,14 @@ static int __devinit ramoops_probe(struct platform_device *pdev) goto fail_out; } - pdata->mem_size = rounddown_pow_of_two(pdata->mem_size); - pdata->record_size = rounddown_pow_of_two(pdata->record_size); - pdata->console_size = rounddown_pow_of_two(pdata->console_size); - pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size); + if (pdata->mem_size) + pdata->mem_size = rounddown_pow_of_two(pdata->mem_size); + if (pdata->record_size) + pdata->record_size = rounddown_pow_of_two(pdata->record_size); + if (pdata->console_size) + pdata->console_size = rounddown_pow_of_two(pdata->console_size); + if (pdata->ftrace_size) + pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size); cxt->dump_read_cnt = 0; cxt->size = pdata->mem_size; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
