| Message ID | 20210811092117.183501-1-dimitri.ledkov@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | UBUNTU: SAUCE: RISC-V: prevent sbi_send_cpumask_ipi race with ftrace | expand |
see the v2 patch with BugLink, Tested-By, SOB headers and comment which series this patch is applicable to. On Wed, Aug 11, 2021 at 10:21 AM Dimitri John Ledkov <dimitri.ledkov@canonical.com> wrote: > > From: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> > > ftrace will patch instructions in sbi_send_cpumask_ipi, which is going to > be used by flush_icache_range, leading to potential races and crashes like > this: > > [ 0.000000] ftrace: allocating 38893 entries in 152 pages > [ 0.000000] Oops - illegal instruction [#1] > [ 0.000000] Modules linked in: > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.11.0-1014-generic #14-Ubuntu > [ 0.000000] epc: ffffffe00000920e ra : ffffffe000009384 sp : ffffffe001803d30 > [ 0.000000] gp : ffffffe001a14240 tp : ffffffe00180f440 t0 : ffffffe07fe38000 > [ 0.000000] t1 : ffffffe0019cd338 t2 : 0000000000000000 s0 : ffffffe001803d70 > [ 0.000000] s1 : 0000000000000000 a0 : ffffffe0000095aa a1 : 0000000000000001 > [ 0.000000] a2 : 0000000000000002 a3 : 0000000000000000 a4 : 0000000000000000 > [ 0.000000] a5 : 0000000000000000 a6 : 0000000000000004 a7 : 0000000052464e43 > [ 0.000000] s2 : 0000000000000002 s3 : 0000000000000001 s4 : 0000000000000000 > [ 0.000000] s5 : 0000000000000000 s6 : 0000000000000000 s7 : 0000000000000000 > [ 0.000000] s8 : ffffffe001a170c0 s9 : 0000000000000001 s10: 0000000000000001 > [ 0.000000] s11: 00000000fffcc5d0 t3 : 0000000000000068 t4 : 000000000000000b > [ 0.000000] t5 : ffffffe0019cd3e0 t6 : ffffffe001803cd8 > [ 0.000000] status: 0000000200000100 badaddr: 000000000513f187 cause: 0000000000000002 > [ 0.000000] ---[ end trace f67eb9af4d8d492b ]--- > [ 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! ]--- > > Where ffffffe00000920e lies in the middle of sbi_send_cpumask_ipi. > > Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> > --- > arch/riscv/kernel/sbi.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c > index b8f82c73deb7..9f85f0656f71 100644 > --- a/arch/riscv/kernel/sbi.c > +++ b/arch/riscv/kernel/sbi.c > @@ -562,7 +562,7 @@ long sbi_get_impid(void) > return __sbi_base_ecall(SBI_EXT_BASE_GET_MIMPID); > } > > -static void sbi_send_cpumask_ipi(const struct cpumask *target) > +static void notrace sbi_send_cpumask_ipi(const struct cpumask *target) > { > struct cpumask hartid_mask; > > -- > 2.30.2 >
diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c index b8f82c73deb7..9f85f0656f71 100644 --- a/arch/riscv/kernel/sbi.c +++ b/arch/riscv/kernel/sbi.c @@ -562,7 +562,7 @@ long sbi_get_impid(void) return __sbi_base_ecall(SBI_EXT_BASE_GET_MIMPID); } -static void sbi_send_cpumask_ipi(const struct cpumask *target) +static void notrace sbi_send_cpumask_ipi(const struct cpumask *target) { struct cpumask hartid_mask;