David Gibson <da...@gibson.dropbear.id.au> 于2020年10月10日周六 下午2:34写道: > > On Fri, Oct 09, 2020 at 07:02:56AM -0700, Elena Afanasova wrote: > > >From 09905773a00e417d3a37c12350d9e55466fdce8a Mon Sep 17 00:00:00 2001 > > From: Elena Afanasova <eafanas...@gmail.com> > > Date: Fri, 9 Oct 2020 06:41:36 -0700 > > Subject: [PATCH] hw/net: move allocation to the heap due to very large stack > > frame > > Patch looks fine, but some more details of the motivation would be > nice. I wouldn't have thought that the size of a network packet > counted as a "very large" stack frame by userspace standards. >
It is also a best practice to avoid large stack allocation according. -->https://wiki.sei.cmu.edu/confluence/display/c/MEM05-C.+Avoid+large+stack+allocations Though I don't see any issue here. Thanks, Li Qiang > > Signed-off-by: Elena Afanasova <eafanas...@gmail.com> > > --- > > hw/net/spapr_llan.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/hw/net/spapr_llan.c b/hw/net/spapr_llan.c > > index 2093f1bad0..581320a0e7 100644 > > --- a/hw/net/spapr_llan.c > > +++ b/hw/net/spapr_llan.c > > @@ -688,7 +688,8 @@ static target_ulong h_send_logical_lan(PowerPCCPU *cpu, > > SpaprVioDevice *sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg); > > SpaprVioVlan *dev = VIO_SPAPR_VLAN_DEVICE(sdev); > > unsigned total_len; > > - uint8_t *lbuf, *p; > > + uint8_t *p; > > + g_autofree uint8_t *lbuf = NULL; > > int i, nbufs; > > int ret; > > > > @@ -729,7 +730,7 @@ static target_ulong h_send_logical_lan(PowerPCCPU *cpu, > > return H_RESOURCE; > > } > > > > - lbuf = alloca(total_len); > > + lbuf = g_malloc(total_len); > > p = lbuf; > > for (i = 0; i < nbufs; i++) { > > ret = spapr_vio_dma_read(sdev, VLAN_BD_ADDR(bufs[i]), > > -- > David Gibson | I'll have my music baroque, and my code > david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ > | _way_ _around_! > http://www.ozlabs.org/~dgibson