This is a note to let you know that I've just added the patch titled
riscv: fix reserved memory setup
to the 6.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
riscv-fix-reserved-memory-setup.patch
and it can be found in the queue-6.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 88495a6856a36c3065d425894c58e71b7ad38e02
Author: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Date: Mon Nov 7 15:15:25 2022 +0000
riscv: fix reserved memory setup
[ Upstream commit 50e63dd8ed92045eb70a72d7ec725488320fb68b ]
Currently, RISC-V sets up reserved memory using the "early" copy of the
device tree. As a result, when trying to get a reserved memory region
using of_reserved_mem_lookup(), the pointer to reserved memory regions
is using the early, pre-virtual-memory address which causes a kernel
panic when trying to use the buffer's name:
Unable to handle kernel paging request at virtual address 00000000401c31ac
Oops [#1]
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 6.0.0-rc1-00001-g0d9d6953d834 #1
Hardware name: Microchip PolarFire-SoC Icicle Kit (DT)
epc : string+0x4a/0xea
ra : vsnprintf+0x1e4/0x336
epc : ffffffff80335ea0 ra : ffffffff80338936 sp : ffffffff81203be0
gp : ffffffff812e0a98 tp : ffffffff8120de40 t0 : 0000000000000000
t1 : ffffffff81203e28 t2 : 7265736572203a46 s0 : ffffffff81203c20
s1 : ffffffff81203e28 a0 : ffffffff81203d22 a1 : 0000000000000000
a2 : ffffffff81203d08 a3 : 0000000081203d21 a4 : ffffffffffffffff
a5 : 00000000401c31ac a6 : ffff0a00ffffff04 a7 : ffffffffffffffff
s2 : ffffffff81203d08 s3 : ffffffff81203d00 s4 : 0000000000000008
s5 : ffffffff000000ff s6 : 0000000000ffffff s7 : 00000000ffffff00
s8 : ffffffff80d9821a s9 : ffffffff81203d22 s10: 0000000000000002
s11: ffffffff80d9821c t3 : ffffffff812f3617 t4 : ffffffff812f3617
t5 : ffffffff812f3618 t6 : ffffffff81203d08
status: 0000000200000100 badaddr: 00000000401c31ac cause: 000000000000000d
[<ffffffff80338936>] vsnprintf+0x1e4/0x336
[<ffffffff80055ae2>] vprintk_store+0xf6/0x344
[<ffffffff80055d86>] vprintk_emit+0x56/0x192
[<ffffffff80055ed8>] vprintk_default+0x16/0x1e
[<ffffffff800563d2>] vprintk+0x72/0x80
[<ffffffff806813b2>] _printk+0x36/0x50
[<ffffffff8068af48>] print_reserved_mem+0x1c/0x24
[<ffffffff808057ec>] paging_init+0x528/0x5bc
[<ffffffff808031ae>] setup_arch+0xd0/0x592
[<ffffffff8080070e>] start_kernel+0x82/0x73c
early_init_fdt_scan_reserved_mem() takes no arguments as it operates on
initial_boot_params, which is populated by early_init_dt_verify(). On
RISC-V, early_init_dt_verify() is called twice. Once, directly, in
setup_arch() if CONFIG_BUILTIN_DTB is not enabled and once indirectly,
very early in the boot process, by parse_dtb() when it calls
early_init_dt_scan_nodes().
This first call uses dtb_early_va to set initial_boot_params, which is
not usable later in the boot process when
early_init_fdt_scan_reserved_mem() is called. On arm64 for example, the
corresponding call to early_init_dt_scan_nodes() uses fixmap addresses
and doesn't suffer the same fate.
Move early_init_fdt_scan_reserved_mem() further along the boot sequence,
after the direct call to early_init_dt_verify() in setup_arch() so that
the names use the correct virtual memory addresses. The above supposed
that CONFIG_BUILTIN_DTB was not set, but should work equally in the case
where it is - unflatted_and_copy_device_tree() also updates
initial_boot_params.
Reported-by: Valentina Fernandez <valentina.fernandezalanis@xxxxxxxxxxxxx>
Reported-by: Evgenii Shatokhin <e.shatokhin@xxxxxxxxx>
Link: https://lore.kernel.org/linux-riscv/f8e67f82-103d-156c-deb0-d6d6e2756f5e@xxxxxxxxxxxxx/
Fixes: 922b0375fc93 ("riscv: Fix memblock reservation for device tree blob")
Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Tested-by: Evgenii Shatokhin <e.shatokhin@xxxxxxxxx>
Link: https://lore.kernel.org/r/20221107151524.3941467-1-conor.dooley@xxxxxxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index ad76bb59b059..67ec1fadcfe2 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -283,6 +283,7 @@ void __init setup_arch(char **cmdline_p)
else
pr_err("No DTB found in kernel mappings\n");
#endif
+ early_init_fdt_scan_reserved_mem();
misc_mem_init();
init_resources();
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index b56a0a75533f..50a1b6edd491 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -262,7 +262,6 @@ static void __init setup_bootmem(void)
memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
}
- early_init_fdt_scan_reserved_mem();
dma_contiguous_reserve(dma32_phys_limit);
if (IS_ENABLED(CONFIG_64BIT))
hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
