| Message ID | 20210509173029.1653182-1-f.fainelli@gmail.com |
|---|---|
| Headers | show |
| Series | ARM FDT relocation backports | expand |
On Mon, May 10, 2021 at 11:37:01AM +0200, Linus Walleij wrote: > On Mon, May 10, 2021 at 9:43 AM Greg Kroah-Hartman > <gregkh@linuxfoundation.org> wrote: > > On Sun, May 09, 2021 at 06:22:05PM -0700, Florian Fainelli wrote: > > > > This does not qualify as a regression in that it has never worked for > > > the specific platform that I have shown above until your 3 commits came > > > in and fixed that particular FDT placement. To me this qualifies as a > > > bug fix, and given that the 3 (now 4) commits applied without hunks, it > > > seems reasonable to me to back port those to stable. > > > > As this isn't a regression, why not just use 5.12 on these platforms? > > Why is 5.4 and 5.10 needed? > > Actually I think it *is* a regression, but not a common one. The bug that > Ard is fixing can appear when the kernel grows over a certain size. > > If a user compile in a new set of functionality and the kernel size > reach a tripping point so that the DTB ends up just outside the 1:1 > lowmem map, disaster strikes. > > This has been a long standing mysterious bug for people using > attached device trees. Ok, then feel free to ack them when they get resubmitted. thanks, greg k-h
Hi Greg, Sasha, These patches were not marked with a Fixes: tag but they do fix booting ARM 32-bit platforms that have specific FDT placement and would cause boot failures like these: [ 0.000000] 8<--- cut here --- [ 0.000000] Unable to handle kernel paging request at virtual address ffa14000 [ 0.000000] pgd = (ptrval) [ 0.000000] [ffa14000] *pgd=80000040007003, *pmd=00000000 [ 0.000000] Internal error: Oops: 206 [#1] SMP ARM [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.4.85-1.0 #1 [ 0.000000] Hardware name: Broadcom STB (Flattened Device Tree) [ 0.000000] PC is at fdt_check_header+0xc/0x21c [ 0.000000] LR is at __unflatten_device_tree+0x7c/0x2f8 [ 0.000000] pc : [<c0d30e44>] lr : [<c0a6c0fc>] psr: 600000d3 [ 0.000000] sp : c1401eac ip : c1401ec8 fp : c1401ec4 [ 0.000000] r10: 00000000 r9 : c150523c r8 : 00000000 [ 0.000000] r7 : c124eab4 r6 : ffa14000 r5 : 00000000 r4 : c14ba920 [ 0.000000] r3 : 00000000 r2 : c150523c r1 : 00000000 r0 : ffa14000 [ 0.000000] Flags: nZCv IRQs off FIQs off Mode SVC_32 ISA ARM Segment user [ 0.000000] Control: 30c5383d Table: 40003000 DAC: fffffffd [ 0.000000] Process swapper (pid: 0, stack limit = 0x(ptrval)) [ 0.000000] Stack: (0xc1401eac to 0xc1402000) [ 0.000000] 1ea0: c14ba920 00000000 ffa14000 c1401ef4 c1401ec8 [ 0.000000] 1ec0: c0a6c0fc c0d30e44 c124eab4 c124eab4 00000000 c14ebfc0 c140e5b8 00000000 [ 0.000000] 1ee0: 00000001 c126f5a0 c1401f14 c1401ef8 c1250064 c0a6c08c 00000000 c1401f08 [ 0.000000] 1f00: c022ddac c140ce80 c1401f9c c1401f18 c120506c c125002c 00000000 00000000 [ 0.000000] 1f20: 00000000 00000000 ffffffff c1401f94 c1401f6c c1406308 3fffffff 00000001 [ 0.000000] 1f40: 00000000 00000001 c1432b58 c14ca180 c1213ca4 c1406308 c1406300 30c0387d [ 0.000000] 1f60: c1401f8c c1401f70 c028e0ec 00000000 c1401f94 c1406308 c1406300 30c0387d [ 0.000000] 1f80: 00000000 7fa14000 420f1000 30c5387d c1401ff4 c1401fa0 c1200c98 c120467c [ 0.000000] 1fa0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 c127fa44 [ 0.000000] 1fc0: 00000000 00000000 00000000 c1200330 00000000 30c0387d ffffffff 7fa14000 [ 0.000000] 1fe0: 420f1000 30c5387d 00000000 c1401ff8 00000000 c1200c28 00000000 00000000 [ 0.000000] Backtrace: [ 0.000000] [<c0d30e38>] (fdt_check_header) from [<c0a6c0fc>] (__unflatten_device_tree+0x7c/0x2f8) [ 0.000000] r6:ffa14000 r5:00000000 r4:c14ba920 [ 0.000000] [<c0a6c080>] (__unflatten_device_tree) from [<c1250064>] (unflatten_device_tree+0x44/0x54) [ 0.000000] r10:c126f5a0 r9:00000001 r8:00000000 r7:c140e5b8 r6:c14ebfc0 r5:00000000 [ 0.000000] r4:c124eab4 r3:c124eab4 [ 0.000000] [<c1250020>] (unflatten_device_tree) from [<c120506c>] (setup_arch+0x9fc/0xc84) [ 0.000000] r4:c140ce80 [ 0.000000] [<c1204670>] (setup_arch) from [<c1200c98>] (start_kernel+0x7c/0x540) [ 0.000000] r10:30c5387d r9:420f1000 r8:7fa14000 r7:00000000 r6:30c0387d r5:c1406300 [ 0.000000] r4:c1406308 [ 0.000000] [<c1200c1c>] (start_kernel) from [<00000000>] (0x0) [ 0.000000] r10:30c5387d r9:420f1000 r8:7fa14000 r7:ffffffff r6:30c0387d r5:00000000 [ 0.000000] r4:c1200330 [ 0.000000] Code: e89da800 e1a0c00d e92dd870 e24cb004 (e5d03000) [ 0.000000] random: get_random_bytes called from print_oops_end_marker+0x50/0x58 with crng_init=0 [ 0.000000] ---[ end trace f34b4929828506c1 ]--- [ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task! [ 0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]--- Ard Biesheuvel (3): ARM: 9011/1: centralize phys-to-virt conversion of DT/ATAGS address ARM: 9012/1: move device tree mapping out of linear region ARM: 9020/1: mm: use correct section size macro to describe the FDT virtual address Documentation/arm/memory.rst | 7 ++++++- arch/arm/include/asm/fixmap.h | 2 +- arch/arm/include/asm/memory.h | 5 +++++ arch/arm/include/asm/prom.h | 4 ++-- arch/arm/kernel/atags.h | 4 ++-- arch/arm/kernel/atags_parse.c | 6 +++--- arch/arm/kernel/devtree.c | 6 +++--- arch/arm/kernel/head.S | 5 ++--- arch/arm/kernel/setup.c | 19 ++++++++++++++----- arch/arm/mm/init.c | 1 - arch/arm/mm/mmu.c | 20 ++++++++++++++------ arch/arm/mm/pv-fixup-asm.S | 4 ++-- 12 files changed, 54 insertions(+), 29 deletions(-)