On Mon, Apr 20, 2020 at 11:20:23AM -0700, Mike Kravetz wrote: > On 4/20/20 8:34 AM, Qian Cai wrote: > > > > > >> On Apr 17, 2020, at 2:50 PM, Mike Kravetz <mike.kravetz@xxxxxxxxxx> wrote: > >> > >> Longpeng(Mike) reported a weird message from hugetlb command line processing > >> and proposed a solution [1]. While the proposed patch does address the > >> specific issue, there are other related issues in command line processing. > >> As hugetlbfs evolved, updates to command line processing have been made to > >> meet immediate needs and not necessarily in a coordinated manner. The result > >> is that some processing is done in arch specific code, some is done in arch > >> independent code and coordination is problematic. Semantics can vary between > >> architectures. > >> > >> The patch series does the following: > >> - Define arch specific arch_hugetlb_valid_size routine used to validate > >> passed huge page sizes. > >> - Move hugepagesz= command line parsing out of arch specific code and into > >> an arch independent routine. > >> - Clean up command line processing to follow desired semantics and > >> document those semantics. > >> > >> [1] https://lore.kernel.org/linux-mm/20200305033014.1152-1-longpeng2@xxxxxxxxxx > >> > >> Mike Kravetz (4): > >> hugetlbfs: add arch_hugetlb_valid_size > >> hugetlbfs: move hugepagesz= parsing to arch independent code > >> hugetlbfs: remove hugetlb_add_hstate() warning for existing hstate > >> hugetlbfs: clean up command line processing > > > > Reverted this series fixed many undefined behaviors on arm64 with the config, > > > > https://raw.githubusercontent.com/cailca/linux-mm/master/arm64.config > > > > [ 54.172683][ T1] UBSAN: shift-out-of-bounds in ./include/linux/hugetlb.h:555:34 > > [ 54.180411][ T1] shift exponent 4294967285 is too large for 64-bit type 'unsigned long' > > [ 54.188885][ T1] CPU: 130 PID: 1 Comm: swapper/0 Not tainted 5.7.0-rc2-next-20200420 #1 > > [ 54.197284][ T1] Hardware name: HPE Apollo 70 /C01_APACHE_MB , BIOS L50_5.13_1.11 06/18/2019 > > [ 54.207888][ T1] Call trace: > > [ 54.211100][ T1] dump_backtrace+0x0/0x224 > > [ 54.215565][ T1] show_stack+0x20/0x2c > > [ 54.219651][ T1] dump_stack+0xfc/0x184 > > [ 54.223829][ T1] __ubsan_handle_shift_out_of_bounds+0x304/0x344 > > [ 54.230204][ T1] hugetlb_add_hstate+0x3ec/0x414 > > huge_page_size at include/linux/hugetlb.h:555 > > (inlined by) hugetlb_add_hstate at mm/hugetlb.c:3301 > > [ 54.235191][ T1] hugetlbpage_init+0x14/0x30 > > [ 54.239824][ T1] do_one_initcall+0x6c/0x144 > > [ 54.244446][ T1] do_initcall_level+0x158/0x1c4 > > [ 54.249336][ T1] do_initcalls+0x68/0xb0 > > [ 54.253597][ T1] do_basic_setup+0x28/0x30 > > [ 54.258049][ T1] kernel_init_freeable+0x19c/0x228 > > [ 54.263188][ T1] kernel_init+0x14/0x208 > > [ 54.267473][ T1] ret_from_fork+0x10/0x18 > > While rearranging the code (patch 3 in series), I made the incorrect > assumption that CONT_XXX_SIZE == (1UL << CONT_XXX_SHIFT). However, > this is not the case. Does the following patch fix these issues? > > From b75cb4a0852e208bee8c4eb347dc076fcaa88859 Mon Sep 17 00:00:00 2001 > From: Mike Kravetz <mike.kravetz@xxxxxxxxxx> > Date: Mon, 20 Apr 2020 10:41:18 -0700 > Subject: [PATCH] arm64/hugetlb: fix hugetlb initialization > > When calling hugetlb_add_hstate() to initialize a new hugetlb size, > be sure to use correct huge pages size order. > > Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> > --- > arch/arm64/mm/hugetlbpage.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c > index 9ca840527296..a02411a1f19a 100644 > --- a/arch/arm64/mm/hugetlbpage.c > +++ b/arch/arm64/mm/hugetlbpage.c > @@ -453,11 +453,11 @@ void huge_ptep_clear_flush(struct vm_area_struct *vma, > static int __init hugetlbpage_init(void) > { > #ifdef CONFIG_ARM64_4K_PAGES > - hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT); > + hugetlb_add_hstate(ilog2(PUD_SIZE) - PAGE_SHIFT); > #endif > - hugetlb_add_hstate(CONT_PMD_SHIFT - PAGE_SHIFT); > - hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT); > - hugetlb_add_hstate(CONT_PTE_SHIFT - PAGE_SHIFT); > + hugetlb_add_hstate(ilog2(CONT_PMD_SIZE) - PAGE_SHIFT); > + hugetlb_add_hstate(ilog2(PMD_SIZE) - PAGE_SHIFT); > + hugetlb_add_hstate(ilog2(CONT_PTE_SIZE) - PAGE_SHIFT); Might be clearer to leave the non CONT_* definitions alone and instead convert the CONT versions along the lines of: hugetlb_add_hstate(CONT_PMD_SHIFT + PMD_SHIFT - PAGE_SHIFT); (untested, but I think that's right...) But that doesn't matter until Qian has confirmed that your patch fixes the issue. Will
