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author | Conor Dooley <conor.dooley@microchip.com> | 2022-11-07 15:15:25 +0000 |
---|---|---|
committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-11-10 14:46:33 -0800 |
commit | 50e63dd8ed92045eb70a72d7ec725488320fb68b (patch) | |
tree | 73fbf6cf269c6ab55f1359f4a90a7eb27b65e3b7 /arch | |
parent | 50f4dd657a0fcf90aa8da8dc2794a8100ff4c37c (diff) | |
download | lwn-50e63dd8ed92045eb70a72d7ec725488320fb68b.tar.gz lwn-50e63dd8ed92045eb70a72d7ec725488320fb68b.zip |
riscv: fix reserved memory setup
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@microchip.com>
Reported-by: Evgenii Shatokhin <e.shatokhin@yadro.com>
Link: https://lore.kernel.org/linux-riscv/f8e67f82-103d-156c-deb0-d6d6e2756f5e@microchip.com/
Fixes: 922b0375fc93 ("riscv: Fix memblock reservation for device tree blob")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Evgenii Shatokhin <e.shatokhin@yadro.com>
Link: https://lore.kernel.org/r/20221107151524.3941467-1-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/riscv/kernel/setup.c | 1 | ||||
-rw-r--r-- | arch/riscv/mm/init.c | 1 |
2 files changed, 1 insertions, 1 deletions
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); |