Re: [PATCH v2] Fix display of Maximum Memory
On Wed, 2020-01-15 at 14:53:59 UTC, Michael Bringmann wrote: > Correct overflow problem in calculation+display of Maximum Memory > value to syscfg where 32bits is insufficient. > > Signed-off-by: Michael Bringmann Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/f1dbc1c5c70d0d4c60b5d467ba941fba167c12f6 cheers
Re: [PATCH v2] Fix display of Maximum Memory
On 1/15/20 11:53 PM, Michael Ellerman wrote: > Michael Bringmann writes: >> Correct overflow problem in calculation+display of Maximum Memory >> value to syscfg where 32bits is insufficient. >> >> Signed-off-by: Michael Bringmann >> --- >> arch/powerpc/platforms/pseries/lparcfg.c | 8 >> 1 file changed, 4 insertions(+), 4 deletions(-) >> >> diff --git a/arch/powerpc/platforms/pseries/lparcfg.c >> b/arch/powerpc/platforms/pseries/lparcfg.c >> index e33e8bc..f00411c 100644 >> --- a/arch/powerpc/platforms/pseries/lparcfg.c >> +++ b/arch/powerpc/platforms/pseries/lparcfg.c >> @@ -433,12 +433,12 @@ static void parse_em_data(struct seq_file *m) >> >> static void maxmem_data(struct seq_file *m) >> { >> -unsigned long maxmem = 0; >> +u64 maxmem = 0; > > This is 64-bit only code, so u64 == unsigned long. > >> -maxmem += drmem_info->n_lmbs * drmem_info->lmb_size; >> -maxmem += hugetlb_total_pages() * PAGE_SIZE; >> +maxmem += (u64)drmem_info->n_lmbs * drmem_info->lmb_size; > > The only problem AFAICS is n_lmbs is int and lmb_size is u32, so this > multiplication will overflow. > >> +maxmem += (u64)hugetlb_total_pages() * PAGE_SIZE; > > hugetlb_total_pages() already returns unsigned long. > >> -seq_printf(m, "MaxMem=%ld\n", maxmem); >> +seq_printf(m, "MaxMem=%llu\n", maxmem); >> } > > This should be sufficient? > > diff --git a/arch/powerpc/platforms/pseries/lparcfg.c > b/arch/powerpc/platforms/pseries/lparcfg.c > index e33e8bc4b69b..38c306551f76 100644 > --- a/arch/powerpc/platforms/pseries/lparcfg.c > +++ b/arch/powerpc/platforms/pseries/lparcfg.c > @@ -435,10 +435,10 @@ static void maxmem_data(struct seq_file *m) > { > unsigned long maxmem = 0; > > - maxmem += drmem_info->n_lmbs * drmem_info->lmb_size; > + maxmem += (unsigned long)drmem_info->n_lmbs * drmem_info->lmb_size; > maxmem += hugetlb_total_pages() * PAGE_SIZE; > > - seq_printf(m, "MaxMem=%ld\n", maxmem); > + seq_printf(m, "MaxMem=%lu\n", maxmem); > } > > static int pseries_lparcfg_data(struct seq_file *m, void *v) > > > cheers > Trying it out. -- Michael W. Bringmann Linux Technology Center IBM Corporation Tie-Line 363-5196 External: (512) 286-5196 Cell: (512) 466-0650 m...@linux.ibm.com
Re: [PATCH v2] Fix display of Maximum Memory
Michael Bringmann writes: > Correct overflow problem in calculation+display of Maximum Memory > value to syscfg where 32bits is insufficient. > > Signed-off-by: Michael Bringmann > --- > arch/powerpc/platforms/pseries/lparcfg.c | 8 > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/powerpc/platforms/pseries/lparcfg.c > b/arch/powerpc/platforms/pseries/lparcfg.c > index e33e8bc..f00411c 100644 > --- a/arch/powerpc/platforms/pseries/lparcfg.c > +++ b/arch/powerpc/platforms/pseries/lparcfg.c > @@ -433,12 +433,12 @@ static void parse_em_data(struct seq_file *m) > > static void maxmem_data(struct seq_file *m) > { > - unsigned long maxmem = 0; > + u64 maxmem = 0; This is 64-bit only code, so u64 == unsigned long. > - maxmem += drmem_info->n_lmbs * drmem_info->lmb_size; > - maxmem += hugetlb_total_pages() * PAGE_SIZE; > + maxmem += (u64)drmem_info->n_lmbs * drmem_info->lmb_size; The only problem AFAICS is n_lmbs is int and lmb_size is u32, so this multiplication will overflow. > + maxmem += (u64)hugetlb_total_pages() * PAGE_SIZE; hugetlb_total_pages() already returns unsigned long. > - seq_printf(m, "MaxMem=%ld\n", maxmem); > + seq_printf(m, "MaxMem=%llu\n", maxmem); > } This should be sufficient? diff --git a/arch/powerpc/platforms/pseries/lparcfg.c b/arch/powerpc/platforms/pseries/lparcfg.c index e33e8bc4b69b..38c306551f76 100644 --- a/arch/powerpc/platforms/pseries/lparcfg.c +++ b/arch/powerpc/platforms/pseries/lparcfg.c @@ -435,10 +435,10 @@ static void maxmem_data(struct seq_file *m) { unsigned long maxmem = 0; - maxmem += drmem_info->n_lmbs * drmem_info->lmb_size; + maxmem += (unsigned long)drmem_info->n_lmbs * drmem_info->lmb_size; maxmem += hugetlb_total_pages() * PAGE_SIZE; - seq_printf(m, "MaxMem=%ld\n", maxmem); + seq_printf(m, "MaxMem=%lu\n", maxmem); } static int pseries_lparcfg_data(struct seq_file *m, void *v) cheers
Re: [PATCH v2] Fix display of Maximum Memory
On 1/15/20 6:53 AM, Michael Bringmann wrote: > Correct overflow problem in calculation+display of Maximum Memory > value to syscfg where 32bits is insufficient. > Probably needs the following Fixes tag: Fixes: 772b039fd9a7 ("powerpc/pseries: Export maximum memory value") otherwise, Reviewed-by: Tyrel Datwyler > Signed-off-by: Michael Bringmann > --- > arch/powerpc/platforms/pseries/lparcfg.c | 8 > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/powerpc/platforms/pseries/lparcfg.c > b/arch/powerpc/platforms/pseries/lparcfg.c > index e33e8bc..f00411c 100644 > --- a/arch/powerpc/platforms/pseries/lparcfg.c > +++ b/arch/powerpc/platforms/pseries/lparcfg.c > @@ -433,12 +433,12 @@ static void parse_em_data(struct seq_file *m) > > static void maxmem_data(struct seq_file *m) > { > - unsigned long maxmem = 0; > + u64 maxmem = 0; > > - maxmem += drmem_info->n_lmbs * drmem_info->lmb_size; > - maxmem += hugetlb_total_pages() * PAGE_SIZE; > + maxmem += (u64)drmem_info->n_lmbs * drmem_info->lmb_size; > + maxmem += (u64)hugetlb_total_pages() * PAGE_SIZE; > > - seq_printf(m, "MaxMem=%ld\n", maxmem); > + seq_printf(m, "MaxMem=%llu\n", maxmem); > } > > static int pseries_lparcfg_data(struct seq_file *m, void *v) >
Re: [PATCH v2] Fix display of Maximum Memory
Le 15/01/2020 à 15:53, Michael Bringmann a écrit : Correct overflow problem in calculation+display of Maximum Memory value to syscfg where 32bits is insufficient. Signed-off-by: Michael Bringmann Reviewed-by: Christophe Leroy --- arch/powerpc/platforms/pseries/lparcfg.c | 8 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/platforms/pseries/lparcfg.c b/arch/powerpc/platforms/pseries/lparcfg.c index e33e8bc..f00411c 100644 --- a/arch/powerpc/platforms/pseries/lparcfg.c +++ b/arch/powerpc/platforms/pseries/lparcfg.c @@ -433,12 +433,12 @@ static void parse_em_data(struct seq_file *m) static void maxmem_data(struct seq_file *m) { - unsigned long maxmem = 0; + u64 maxmem = 0; - maxmem += drmem_info->n_lmbs * drmem_info->lmb_size; - maxmem += hugetlb_total_pages() * PAGE_SIZE; + maxmem += (u64)drmem_info->n_lmbs * drmem_info->lmb_size; + maxmem += (u64)hugetlb_total_pages() * PAGE_SIZE; - seq_printf(m, "MaxMem=%ld\n", maxmem); + seq_printf(m, "MaxMem=%llu\n", maxmem); } static int pseries_lparcfg_data(struct seq_file *m, void *v)
[PATCH v2] Fix display of Maximum Memory
Correct overflow problem in calculation+display of Maximum Memory value to syscfg where 32bits is insufficient. Signed-off-by: Michael Bringmann --- arch/powerpc/platforms/pseries/lparcfg.c | 8 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/platforms/pseries/lparcfg.c b/arch/powerpc/platforms/pseries/lparcfg.c index e33e8bc..f00411c 100644 --- a/arch/powerpc/platforms/pseries/lparcfg.c +++ b/arch/powerpc/platforms/pseries/lparcfg.c @@ -433,12 +433,12 @@ static void parse_em_data(struct seq_file *m) static void maxmem_data(struct seq_file *m) { - unsigned long maxmem = 0; + u64 maxmem = 0; - maxmem += drmem_info->n_lmbs * drmem_info->lmb_size; - maxmem += hugetlb_total_pages() * PAGE_SIZE; + maxmem += (u64)drmem_info->n_lmbs * drmem_info->lmb_size; + maxmem += (u64)hugetlb_total_pages() * PAGE_SIZE; - seq_printf(m, "MaxMem=%ld\n", maxmem); + seq_printf(m, "MaxMem=%llu\n", maxmem); } static int pseries_lparcfg_data(struct seq_file *m, void *v) -- 1.8.3.1