* [PATCH] arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region @ 2018-12-24 7:40 Yueyi Li 2018-12-24 9:45 ` Ard Biesheuvel 0 siblings, 1 reply; 9+ messages in thread From: Yueyi Li @ 2018-12-24 7:40 UTC (permalink / raw) To: catalin.marinas, will.deacon, akpm Cc: markus, linux-kernel, linux-arm-kernel, ard.biesheuvel When KASLR enaled(CONFIG_RANDOMIZE_BASE=y), the top 4K virtual address have chance to be mapped to physical address, but which is expected to leave room for ERR_PTR. Also, it might cause some other warparound issue when somewhere use the last memory page but no overflow check. Such as the last page compressed by LZO: [ 2738.034508] Unable to handle kernel NULL pointer dereference at virtual address 00000009 [ 2738.034515] Mem abort info: [ 2738.034518] Exception class = DABT (current EL), IL = 32 bits [ 2738.034520] SET = 0, FnV = 0 [ 2738.034523] EA = 0, S1PTW = 0 [ 2738.034524] FSC = 5 [ 2738.034526] Data abort info: [ 2738.034528] ISV = 0, ISS = 0x00000005 [ 2738.034530] CM = 0, WnR = 0 [ 2738.034533] user pgtable: 4k pages, 39-bit VAs, pgd = ffffffff94cee000 [ 2738.034535] [0000000000000009] *pgd=0000000000000000, *pud=0000000000000000 ... [ 2738.034592] pc : lzo1x_1_do_compress+0x198/0x610 [ 2738.034595] lr : lzo1x_1_compress+0x98/0x3d8 [ 2738.034597] sp : ffffff801caa3470 pstate : 00c00145 [ 2738.034598] x29: ffffff801caa3500 x28: 0000000000001000 [ 2738.034601] x27: 0000000000001000 x26: fffffffffffff000 [ 2738.034604] x25: ffffffff4ebc0000 x24: 0000000000000000 [ 2738.034607] x23: 000000000000004c x22: fffffffffffff7b8 [ 2738.034610] x21: ffffffff2e2ee0b3 x20: ffffffff2e2ee0bb [ 2738.034612] x19: 0000000000000fcc x18: fffffffffffff84a [ 2738.034615] x17: 00000000801b03d6 x16: 0000000000000782 [ 2738.034618] x15: ffffffff2e2ee0bf x14: fffffffffffffff0 [ 2738.034620] x13: 000000000000000f x12: 0000000000000020 [ 2738.034623] x11: 000000001824429d x10: ffffffffffffffec [ 2738.034626] x9 : 0000000000000009 x8 : 0000000000000000 [ 2738.034628] x7 : 0000000000000868 x6 : 0000000000000434 [ 2738.034631] x5 : ffffffff4ebc0000 x4 : 0000000000000000 [ 2738.034633] x3 : ffffff801caa3510 x2 : ffffffff2e2ee000 [ 2738.034636] x1 : 0000000000000000 x0 : fffffffffffff000 ... [ 2738.034717] Process kworker/u16:1 (pid: 8705, stack limit = 0xffffff801caa0000) [ 2738.034720] Call trace: [ 2738.034722] lzo1x_1_do_compress+0x198/0x610 [ 2738.034725] lzo_compress+0x48/0x88 [ 2738.034729] crypto_compress+0x14/0x20 [ 2738.034733] zcomp_compress+0x2c/0x38 [ 2738.034736] zram_bvec_rw+0x3d0/0x860 [ 2738.034738] zram_rw_page+0x88/0xe0 [ 2738.034742] bdev_write_page+0x70/0xc0 [ 2738.034745] __swap_writepage+0x58/0x3f8 [ 2738.034747] swap_writepage+0x40/0x50 [ 2738.034750] shrink_page_list+0x4fc/0xe58 [ 2738.034753] reclaim_pages_from_list+0xa0/0x150 [ 2738.034756] reclaim_pte_range+0x18c/0x1f8 [ 2738.034759] __walk_page_range+0xf8/0x1e0 [ 2738.034762] walk_page_range+0xf8/0x130 [ 2738.034765] reclaim_task_anon+0xcc/0x168 [ 2738.034767] swap_fn+0x438/0x668 [ 2738.034771] process_one_work+0x1fc/0x460 [ 2738.034773] worker_thread+0x2d0/0x478 [ 2738.034775] kthread+0x110/0x120 [ 2738.034778] ret_from_fork+0x10/0x18 [ 2738.034781] Code: 3800167f 54ffffa8 d100066f 14000031 (b9400131) [ 2738.034784] ---[ end trace 9b5cca106f0e54d1 ]--- [ 2738.035473] Kernel panic - not syncing: Fatal exception in = 0xfffffffffffff000 in_len = 4096 ip = x9 = 0x0000000000000009 overflowed. Always leave room the last size of ARM64_MEMSTART_ALIGN region in linear region. Signed-off-by: liyueyi <liyueyi@live.com> --- arch/arm64/mm/init.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 0340e45..20fe11e 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -439,7 +439,8 @@ void __init arm64_memblock_init(void) if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { extern u16 memstart_offset_seed; u64 range = linear_region_size - - (memblock_end_of_DRAM() - memblock_start_of_DRAM()); + (memblock_end_of_DRAM() - memblock_start_of_DRAM()) - + ARM64_MEMSTART_ALIGN; /* * If the size of the linear region exceeds, by a sufficient -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region 2018-12-24 7:40 [PATCH] arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region Yueyi Li @ 2018-12-24 9:45 ` Ard Biesheuvel 2018-12-25 2:30 ` Yueyi Li 0 siblings, 1 reply; 9+ messages in thread From: Ard Biesheuvel @ 2018-12-24 9:45 UTC (permalink / raw) To: Yueyi Li Cc: catalin.marinas, markus, will.deacon, linux-kernel, akpm, linux-arm-kernel On Mon, 24 Dec 2018 at 08:40, Yueyi Li <liyueyi@live.com> wrote: > > When KASLR enaled(CONFIG_RANDOMIZE_BASE=y), the top 4K virtual > address have chance to be mapped to physical address, but which > is expected to leave room for ERR_PTR. > > Also, it might cause some other warparound issue when somewhere > use the last memory page but no overflow check. Such as the last > page compressed by LZO: > > [ 2738.034508] Unable to handle kernel NULL pointer dereference at virtual address 00000009 > [ 2738.034515] Mem abort info: > [ 2738.034518] Exception class = DABT (current EL), IL = 32 bits > [ 2738.034520] SET = 0, FnV = 0 > [ 2738.034523] EA = 0, S1PTW = 0 > [ 2738.034524] FSC = 5 > [ 2738.034526] Data abort info: > [ 2738.034528] ISV = 0, ISS = 0x00000005 > [ 2738.034530] CM = 0, WnR = 0 > [ 2738.034533] user pgtable: 4k pages, 39-bit VAs, pgd = ffffffff94cee000 > [ 2738.034535] [0000000000000009] *pgd=0000000000000000, *pud=0000000000000000 > ... > [ 2738.034592] pc : lzo1x_1_do_compress+0x198/0x610 > [ 2738.034595] lr : lzo1x_1_compress+0x98/0x3d8 > [ 2738.034597] sp : ffffff801caa3470 pstate : 00c00145 > [ 2738.034598] x29: ffffff801caa3500 x28: 0000000000001000 > [ 2738.034601] x27: 0000000000001000 x26: fffffffffffff000 > [ 2738.034604] x25: ffffffff4ebc0000 x24: 0000000000000000 > [ 2738.034607] x23: 000000000000004c x22: fffffffffffff7b8 > [ 2738.034610] x21: ffffffff2e2ee0b3 x20: ffffffff2e2ee0bb > [ 2738.034612] x19: 0000000000000fcc x18: fffffffffffff84a > [ 2738.034615] x17: 00000000801b03d6 x16: 0000000000000782 > [ 2738.034618] x15: ffffffff2e2ee0bf x14: fffffffffffffff0 > [ 2738.034620] x13: 000000000000000f x12: 0000000000000020 > [ 2738.034623] x11: 000000001824429d x10: ffffffffffffffec > [ 2738.034626] x9 : 0000000000000009 x8 : 0000000000000000 > [ 2738.034628] x7 : 0000000000000868 x6 : 0000000000000434 > [ 2738.034631] x5 : ffffffff4ebc0000 x4 : 0000000000000000 > [ 2738.034633] x3 : ffffff801caa3510 x2 : ffffffff2e2ee000 > [ 2738.034636] x1 : 0000000000000000 x0 : fffffffffffff000 > ... > [ 2738.034717] Process kworker/u16:1 (pid: 8705, stack limit = 0xffffff801caa0000) > [ 2738.034720] Call trace: > [ 2738.034722] lzo1x_1_do_compress+0x198/0x610 > [ 2738.034725] lzo_compress+0x48/0x88 > [ 2738.034729] crypto_compress+0x14/0x20 > [ 2738.034733] zcomp_compress+0x2c/0x38 > [ 2738.034736] zram_bvec_rw+0x3d0/0x860 > [ 2738.034738] zram_rw_page+0x88/0xe0 > [ 2738.034742] bdev_write_page+0x70/0xc0 > [ 2738.034745] __swap_writepage+0x58/0x3f8 > [ 2738.034747] swap_writepage+0x40/0x50 > [ 2738.034750] shrink_page_list+0x4fc/0xe58 > [ 2738.034753] reclaim_pages_from_list+0xa0/0x150 > [ 2738.034756] reclaim_pte_range+0x18c/0x1f8 > [ 2738.034759] __walk_page_range+0xf8/0x1e0 > [ 2738.034762] walk_page_range+0xf8/0x130 > [ 2738.034765] reclaim_task_anon+0xcc/0x168 > [ 2738.034767] swap_fn+0x438/0x668 > [ 2738.034771] process_one_work+0x1fc/0x460 > [ 2738.034773] worker_thread+0x2d0/0x478 > [ 2738.034775] kthread+0x110/0x120 > [ 2738.034778] ret_from_fork+0x10/0x18 > [ 2738.034781] Code: 3800167f 54ffffa8 d100066f 14000031 (b9400131) > [ 2738.034784] ---[ end trace 9b5cca106f0e54d1 ]--- > [ 2738.035473] Kernel panic - not syncing: Fatal exception > > in = 0xfffffffffffff000 > in_len = 4096 > ip = x9 = 0x0000000000000009 overflowed. > > Always leave room the last size of ARM64_MEMSTART_ALIGN region > in linear region. > > Signed-off-by: liyueyi <liyueyi@live.com> > --- > arch/arm64/mm/init.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index 0340e45..20fe11e 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -439,7 +439,8 @@ void __init arm64_memblock_init(void) > if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { > extern u16 memstart_offset_seed; > u64 range = linear_region_size - > - (memblock_end_of_DRAM() - memblock_start_of_DRAM()); > + (memblock_end_of_DRAM() - memblock_start_of_DRAM()) - > + ARM64_MEMSTART_ALIGN; > > /* > * If the size of the linear region exceeds, by a sufficient Does the following change fix your issue as well? index 9b432d9fcada..9dcf0ff75a11 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -447,7 +447,7 @@ void __init arm64_memblock_init(void) * memory spans, randomize the linear region as well. */ if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) { - range = range / ARM64_MEMSTART_ALIGN + 1; + range /= ARM64_MEMSTART_ALIGN; memstart_addr -= ARM64_MEMSTART_ALIGN * ((range * memstart_offset_seed) >> 16); } _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region 2018-12-24 9:45 ` Ard Biesheuvel @ 2018-12-25 2:30 ` Yueyi Li 2018-12-26 13:49 ` Ard Biesheuvel 0 siblings, 1 reply; 9+ messages in thread From: Yueyi Li @ 2018-12-25 2:30 UTC (permalink / raw) To: Ard Biesheuvel Cc: catalin.marinas, markus, will.deacon, linux-kernel, akpm, linux-arm-kernel Hi Ard, On 2018/12/24 17:45, Ard Biesheuvel wrote: > Does the following change fix your issue as well? > > index 9b432d9fcada..9dcf0ff75a11 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -447,7 +447,7 @@ void __init arm64_memblock_init(void) > * memory spans, randomize the linear region as well. > */ > if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) { > - range = range / ARM64_MEMSTART_ALIGN + 1; > + range /= ARM64_MEMSTART_ALIGN; > memstart_addr -= ARM64_MEMSTART_ALIGN * > ((range * memstart_offset_seed) >> 16); > } Yes, it can fix this also. I just think modify the first *range* calculation would be easier to grasp, what do you think? Thanks, Yueyi _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region 2018-12-25 2:30 ` Yueyi Li @ 2018-12-26 13:49 ` Ard Biesheuvel 2019-01-16 3:37 ` Yueyi Li 0 siblings, 1 reply; 9+ messages in thread From: Ard Biesheuvel @ 2018-12-26 13:49 UTC (permalink / raw) To: Yueyi Li Cc: catalin.marinas, markus, will.deacon, linux-kernel, akpm, linux-arm-kernel On Tue, 25 Dec 2018 at 03:30, Yueyi Li <liyueyi@live.com> wrote: > > Hi Ard, > > > On 2018/12/24 17:45, Ard Biesheuvel wrote: > > Does the following change fix your issue as well? > > > > index 9b432d9fcada..9dcf0ff75a11 100644 > > --- a/arch/arm64/mm/init.c > > +++ b/arch/arm64/mm/init.c > > @@ -447,7 +447,7 @@ void __init arm64_memblock_init(void) > > * memory spans, randomize the linear region as well. > > */ > > if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) { > > - range = range / ARM64_MEMSTART_ALIGN + 1; > > + range /= ARM64_MEMSTART_ALIGN; > > memstart_addr -= ARM64_MEMSTART_ALIGN * > > ((range * memstart_offset_seed) >> 16); > > } > > Yes, it can fix this also. I just think modify the first *range* > calculation would be easier to grasp, what do you think? > I don't think there is a difference, to be honest, but I will leave it up to the maintainers to decide which approach they prefer. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region 2018-12-26 13:49 ` Ard Biesheuvel @ 2019-01-16 3:37 ` Yueyi Li 2019-01-16 7:51 ` Ard Biesheuvel 0 siblings, 1 reply; 9+ messages in thread From: Yueyi Li @ 2019-01-16 3:37 UTC (permalink / raw) To: Ard Biesheuvel, catalin.marinas, will.deacon, akpm Cc: markus, linux-kernel, linux-arm-kernel OK, thanks. But seems this mail be ignored, do i need re-sent the patch? On 2018/12/26 21:49, Ard Biesheuvel wrote: > On Tue, 25 Dec 2018 at 03:30, Yueyi Li <liyueyi@live.com> wrote: >> Hi Ard, >> >> >> On 2018/12/24 17:45, Ard Biesheuvel wrote: >>> Does the following change fix your issue as well? >>> >>> index 9b432d9fcada..9dcf0ff75a11 100644 >>> --- a/arch/arm64/mm/init.c >>> +++ b/arch/arm64/mm/init.c >>> @@ -447,7 +447,7 @@ void __init arm64_memblock_init(void) >>> * memory spans, randomize the linear region as well. >>> */ >>> if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) { >>> - range = range / ARM64_MEMSTART_ALIGN + 1; >>> + range /= ARM64_MEMSTART_ALIGN; >>> memstart_addr -= ARM64_MEMSTART_ALIGN * >>> ((range * memstart_offset_seed) >> 16); >>> } >> Yes, it can fix this also. I just think modify the first *range* >> calculation would be easier to grasp, what do you think? >> > I don't think there is a difference, to be honest, but I will leave it > up to the maintainers to decide which approach they prefer. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region 2019-01-16 3:37 ` Yueyi Li @ 2019-01-16 7:51 ` Ard Biesheuvel 2019-01-16 8:38 ` Yueyi Li 0 siblings, 1 reply; 9+ messages in thread From: Ard Biesheuvel @ 2019-01-16 7:51 UTC (permalink / raw) To: Yueyi Li Cc: catalin.marinas, markus, will.deacon, linux-kernel, akpm, linux-arm-kernel On Wed, 16 Jan 2019 at 04:37, Yueyi Li <liyueyi@live.com> wrote: > > OK, thanks. But seems this mail be ignored, do i need re-sent the patch? > > On 2018/12/26 21:49, Ard Biesheuvel wrote: > > On Tue, 25 Dec 2018 at 03:30, Yueyi Li <liyueyi@live.com> wrote: > >> Hi Ard, > >> > >> > >> On 2018/12/24 17:45, Ard Biesheuvel wrote: > >>> Does the following change fix your issue as well? > >>> > >>> index 9b432d9fcada..9dcf0ff75a11 100644 > >>> --- a/arch/arm64/mm/init.c > >>> +++ b/arch/arm64/mm/init.c > >>> @@ -447,7 +447,7 @@ void __init arm64_memblock_init(void) > >>> * memory spans, randomize the linear region as well. > >>> */ > >>> if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) { > >>> - range = range / ARM64_MEMSTART_ALIGN + 1; > >>> + range /= ARM64_MEMSTART_ALIGN; > >>> memstart_addr -= ARM64_MEMSTART_ALIGN * > >>> ((range * memstart_offset_seed) >> 16); > >>> } > >> Yes, it can fix this also. I just think modify the first *range* > >> calculation would be easier to grasp, what do you think? > >> > > I don't think there is a difference, to be honest, but I will leave it > > up to the maintainers to decide which approach they prefer. > No it has been merged already. It is in v5.0-rc2 I think. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region 2019-01-16 7:51 ` Ard Biesheuvel @ 2019-01-16 8:38 ` Yueyi Li 2019-04-13 12:41 ` Nicolas Boichat 0 siblings, 1 reply; 9+ messages in thread From: Yueyi Li @ 2019-01-16 8:38 UTC (permalink / raw) To: Ard Biesheuvel Cc: catalin.marinas, markus, will.deacon, linux-kernel, akpm, linux-arm-kernel On 2019/1/16 15:51, Ard Biesheuvel wrote: > On Wed, 16 Jan 2019 at 04:37, Yueyi Li <liyueyi@live.com> wrote: >> OK, thanks. But seems this mail be ignored, do i need re-sent the patch? >> >> On 2018/12/26 21:49, Ard Biesheuvel wrote: >>> On Tue, 25 Dec 2018 at 03:30, Yueyi Li <liyueyi@live.com> wrote: >>>> Hi Ard, >>>> >>>> >>>> On 2018/12/24 17:45, Ard Biesheuvel wrote: >>>>> Does the following change fix your issue as well? >>>>> >>>>> index 9b432d9fcada..9dcf0ff75a11 100644 >>>>> --- a/arch/arm64/mm/init.c >>>>> +++ b/arch/arm64/mm/init.c >>>>> @@ -447,7 +447,7 @@ void __init arm64_memblock_init(void) >>>>> * memory spans, randomize the linear region as well. >>>>> */ >>>>> if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) { >>>>> - range = range / ARM64_MEMSTART_ALIGN + 1; >>>>> + range /= ARM64_MEMSTART_ALIGN; >>>>> memstart_addr -= ARM64_MEMSTART_ALIGN * >>>>> ((range * memstart_offset_seed) >> 16); >>>>> } >>>> Yes, it can fix this also. I just think modify the first *range* >>>> calculation would be easier to grasp, what do you think? >>>> >>> I don't think there is a difference, to be honest, but I will leave it >>> up to the maintainers to decide which approach they prefer. > No it has been merged already. It is in v5.0-rc2 I think. OK, thanks. :-) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region 2019-01-16 8:38 ` Yueyi Li @ 2019-04-13 12:41 ` Nicolas Boichat 2019-04-13 14:38 ` Sasha Levin 0 siblings, 1 reply; 9+ messages in thread From: Nicolas Boichat @ 2019-04-13 12:41 UTC (permalink / raw) To: stable Cc: Yueyi Li, Ard Biesheuvel, catalin.marinas, markus, will.deacon, linux-kernel, Guenter Roeck, akpm, linux-arm-kernel Dear stable maintainers, I encountered a similar issue on a 4.19.33 kernel (Chromium OS). On my board, the system would not even be able to boot if KASLR decides to map the linear region to the top of the virtual address space. This happens every 253 boots on average (there are 0xfd possible random offsets, and only the top one fails). I tried to debug the issue, and it appears physical memory allocated for vmemmap and mem_section array would end up at the same location, corrupting each other early on boot. I could not figure out exactly why this is happening, but in any case, this patch fixes my issue (no failure in 744 reboots with 240 unique offsets, and counting...), and IMHO the ERR_PTR justification in the commit message is enough to warrant inclusion in -stable branches. The patch below was committed to mainline as: commit c8a43c18a97845e7f94ed7d181c11f41964976a2 arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region and should be included in stable branches after this commit: Fixes: c031a4213c11a5db ("arm64: kaslr: randomize the linear region") i.e. anything after kernel 4.5 (git describe says v4.5-rc4-62-gc031a4213c11a5d). Thanks, Nicolas On Wed, Jan 16, 2019 at 4:38 PM Yueyi Li <liyueyi@live.com> wrote: > > > > On 2019/1/16 15:51, Ard Biesheuvel wrote: > > On Wed, 16 Jan 2019 at 04:37, Yueyi Li <liyueyi@live.com> wrote: > >> OK, thanks. But seems this mail be ignored, do i need re-sent the patch? > >> > >> On 2018/12/26 21:49, Ard Biesheuvel wrote: > >>> On Tue, 25 Dec 2018 at 03:30, Yueyi Li <liyueyi@live.com> wrote: > >>>> Hi Ard, > >>>> > >>>> > >>>> On 2018/12/24 17:45, Ard Biesheuvel wrote: > >>>>> Does the following change fix your issue as well? > >>>>> > >>>>> index 9b432d9fcada..9dcf0ff75a11 100644 > >>>>> --- a/arch/arm64/mm/init.c > >>>>> +++ b/arch/arm64/mm/init.c > >>>>> @@ -447,7 +447,7 @@ void __init arm64_memblock_init(void) > >>>>> * memory spans, randomize the linear region as well. > >>>>> */ > >>>>> if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) { > >>>>> - range = range / ARM64_MEMSTART_ALIGN + 1; > >>>>> + range /= ARM64_MEMSTART_ALIGN; > >>>>> memstart_addr -= ARM64_MEMSTART_ALIGN * > >>>>> ((range * memstart_offset_seed) >> 16); > >>>>> } > >>>> Yes, it can fix this also. I just think modify the first *range* > >>>> calculation would be easier to grasp, what do you think? > >>>> > >>> I don't think there is a difference, to be honest, but I will leave it > >>> up to the maintainers to decide which approach they prefer. > > No it has been merged already. It is in v5.0-rc2 I think. > > OK, thanks. :-) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region 2019-04-13 12:41 ` Nicolas Boichat @ 2019-04-13 14:38 ` Sasha Levin 0 siblings, 0 replies; 9+ messages in thread From: Sasha Levin @ 2019-04-13 14:38 UTC (permalink / raw) To: Nicolas Boichat Cc: Yueyi Li, Ard Biesheuvel, catalin.marinas, markus, will.deacon, linux-kernel, stable, Guenter Roeck, akpm, linux-arm-kernel On Sat, Apr 13, 2019 at 08:41:33PM +0800, Nicolas Boichat wrote: >Dear stable maintainers, > >I encountered a similar issue on a 4.19.33 kernel (Chromium OS). On my >board, the system would not even be able to boot if KASLR decides to >map the linear region to the top of the virtual address space. This >happens every 253 boots on average (there are 0xfd possible random >offsets, and only the top one fails). > >I tried to debug the issue, and it appears physical memory allocated >for vmemmap and mem_section array would end up at the same location, >corrupting each other early on boot. I could not figure out exactly >why this is happening, but in any case, this patch fixes my issue (no >failure in 744 reboots with 240 unique offsets, and counting...), and >IMHO the ERR_PTR justification in the commit message is enough to >warrant inclusion in -stable branches. > >The patch below was committed to mainline as: >commit c8a43c18a97845e7f94ed7d181c11f41964976a2 > arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region > >and should be included in stable branches after this commit: >Fixes: c031a4213c11a5db ("arm64: kaslr: randomize the linear region") >i.e. anything after kernel 4.5 (git describe says v4.5-rc4-62-gc031a4213c11a5d). I've queued it for 4.9-4.19, thanks for the report. -- Thanks, Sasha _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2019-04-13 14:38 UTC | newest] Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2018-12-24 7:40 [PATCH] arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region Yueyi Li 2018-12-24 9:45 ` Ard Biesheuvel 2018-12-25 2:30 ` Yueyi Li 2018-12-26 13:49 ` Ard Biesheuvel 2019-01-16 3:37 ` Yueyi Li 2019-01-16 7:51 ` Ard Biesheuvel 2019-01-16 8:38 ` Yueyi Li 2019-04-13 12:41 ` Nicolas Boichat 2019-04-13 14:38 ` Sasha Levin
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