24fc18087f
We call jump_label_init() in setup_arch() is to use static key
mechanism earlier, but riscv jump label relies on the sbi functions,
If we enable static key before sbi_init(), the code path looks like:
static_branch_enable()
..
arch_jump_label_transform()
patch_text_nosync()
flush_icache_range()
flush_icache_all()
sbi_remote_fence_i() for CONFIG_RISCV_SBI case
__sbi_rfence()
Since sbi isn't initialized, so NULL deference! Here is a typical
panic log:
[ 0.000000] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[ 0.000000] Oops [#1]
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.18.0-rc7+ #79
[ 0.000000] Hardware name: riscv-virtio,qemu (DT)
[ 0.000000] epc : 0x0
[ 0.000000] ra : sbi_remote_fence_i+0x1e/0x26
[ 0.000000] epc : 0000000000000000 ra : ffffffff80005826 sp : ffffffff80c03d50
[ 0.000000] gp : ffffffff80ca6178 tp : ffffffff80c0ad80 t0 : 6200000000000000
[ 0.000000] t1 : 0000000000000000 t2 : 62203a6b746e6972 s0 : ffffffff80c03d60
[ 0.000000] s1 : ffffffff80001af6 a0 : 0000000000000000 a1 : 0000000000000000
[ 0.000000] a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000
[ 0.000000] a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000080200
[ 0.000000] s2 : ffffffff808b3e48 s3 : ffffffff808bf698 s4 : ffffffff80cb2818
[ 0.000000] s5 : 0000000000000001 s6 : ffffffff80c9c345 s7 : ffffffff80895aa0
[ 0.000000] s8 : 0000000000000001 s9 : 000000000000007f s10: 0000000000000000
[ 0.000000] s11: 0000000000000000 t3 : ffffffff80824d08 t4 : 0000000000000022
[ 0.000000] t5 : 000000000000003d t6 : 0000000000000000
[ 0.000000] status: 0000000000000100 badaddr: 0000000000000000 cause: 000000000000000c
[ 0.000000] ---[ end trace 0000000000000000 ]---
[ 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! ]---
Fix this issue by moving sbi_init() earlier before jump_label_init()
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20230515054928.2079268-2-sunilvl@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.