* Tejun Heo <tj@xxxxxxxxxx> wrote: > percpu code has been assuming num_possible_cpus() == nr_cpu_ids which > is incorrect if cpu_possible_map contains holes. This causes percpu > code to access beyond allocated memories and vmalloc areas. On a > sparc64 machine with cpus 0 and 2 (u60), this triggers the following > warning or fails boot. > > WARNING: at /devel/tj/os/work/mm/vmalloc.c:106 vmap_page_range_noflush+0x1f0/0x240() > Modules linked in: > Call Trace: > [00000000004b17d0] vmap_page_range_noflush+0x1f0/0x240 > [00000000004b1840] map_vm_area+0x20/0x60 > [00000000004b1950] __vmalloc_area_node+0xd0/0x160 > [0000000000593434] deflate_init+0x14/0xe0 > [0000000000583b94] __crypto_alloc_tfm+0xd4/0x1e0 > [00000000005844f0] crypto_alloc_base+0x50/0xa0 > [000000000058b898] alg_test_comp+0x18/0x80 > [000000000058dad4] alg_test+0x54/0x180 > [000000000058af00] cryptomgr_test+0x40/0x60 > [0000000000473098] kthread+0x58/0x80 > [000000000042b590] kernel_thread+0x30/0x60 > [0000000000472fd0] kthreadd+0xf0/0x160 > ---[ end trace 429b268a213317ba ]--- > > This patch fixes generic percpu functions and sparc64 > setup_per_cpu_areas() so that they handle sparse cpu_possible_map > properly. > > Please note that on x86, cpu_possible_map() doesn't contain holes and > thus num_possible_cpus() == nr_cpu_ids and this patch doesn't cause > any behavior difference. > > Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> > Cc: David S. Miller <davem@xxxxxxxxxxxxx> > Cc: Ingo Molnar <mingo@xxxxxxx> > --- > As written in the previous mail, this fixes rather critical boot > problem on sparc64. Upon ack, I can get it through the percpu tree. > Not really sure who could ack this one other than David tho. Anyone? > > Thanks. > > arch/sparc/kernel/smp_64.c | 4 ++-- > arch/x86/kernel/setup_percpu.c | 14 +++++++------- > mm/percpu.c | 31 +++++++++++++++++++------------ > 3 files changed, 28 insertions(+), 21 deletions(-) for the x86 bits: Acked-by: Ingo Molnar <mingo@xxxxxxx> Once Dave acks it i suspect you can send it to Linus directly? Ingo -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
