diff options
| author | Geert Uytterhoeven <geert@linux-m68k.org> | 2022-01-31 14:26:22 +0100 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-02-14 12:27:45 -0800 |
| commit | 5feef64f4c67068c49f5409d43c67cabf2327f66 (patch) | |
| tree | 9ab6716e6c0be760c787c49717cf8aa00a4c7d53 /arch/riscv/kernel/sbi.c | |
| parent | 2b35d5b7d13062b805aa82dc53812a5f56249287 (diff) | |
| download | linux-5feef64f4c67068c49f5409d43c67cabf2327f66.tar.bz2 | |
RISC-V: Fix IPI/RFENCE hmask on non-monotonic hartid ordering
If the boot CPU does not have the lowest hartid, "hartid - hbase" can
become negative, leading to an incorrect hmask, causing userspace to
crash with SEGV. This is observed on e.g. Starlight Beta, where cpuid 1
maps to hartid 0, and cpuid 0 maps to hartid 1.
Fix this by detecting this case, and shifting the accumulated mask and
updating hbase, if possible.
Fixes: 26fb751ca37846c9 ("RISC-V: Do not use cpumask data structure for hartid bitmap")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/kernel/sbi.c')
| -rw-r--r-- | arch/riscv/kernel/sbi.c | 57 |
1 files changed, 39 insertions, 18 deletions
diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c index 22444cfcd56c..775d3322b422 100644 --- a/arch/riscv/kernel/sbi.c +++ b/arch/riscv/kernel/sbi.c @@ -250,7 +250,7 @@ static void __sbi_set_timer_v02(uint64_t stime_value) static int __sbi_send_ipi_v02(const struct cpumask *cpu_mask) { - unsigned long hartid, cpuid, hmask = 0, hbase = 0; + unsigned long hartid, cpuid, hmask = 0, hbase = 0, htop = 0; struct sbiret ret = {0}; int result; @@ -259,16 +259,27 @@ static int __sbi_send_ipi_v02(const struct cpumask *cpu_mask) for_each_cpu(cpuid, cpu_mask) { hartid = cpuid_to_hartid_map(cpuid); - if (hmask && ((hbase + BITS_PER_LONG) <= hartid)) { - ret = sbi_ecall(SBI_EXT_IPI, SBI_EXT_IPI_SEND_IPI, - hmask, hbase, 0, 0, 0, 0); - if (ret.error) - goto ecall_failed; - hmask = 0; - hbase = 0; + if (hmask) { + if (hartid + BITS_PER_LONG <= htop || + hbase + BITS_PER_LONG <= hartid) { + ret = sbi_ecall(SBI_EXT_IPI, + SBI_EXT_IPI_SEND_IPI, hmask, + hbase, 0, 0, 0, 0); + if (ret.error) + goto ecall_failed; + hmask = 0; + } else if (hartid < hbase) { + /* shift the mask to fit lower hartid */ + hmask <<= hbase - hartid; + hbase = hartid; + } } - if (!hmask) + if (!hmask) { hbase = hartid; + htop = hartid; + } else if (hartid > htop) { + htop = hartid; + } hmask |= BIT(hartid - hbase); } @@ -345,7 +356,7 @@ static int __sbi_rfence_v02(int fid, const struct cpumask *cpu_mask, unsigned long start, unsigned long size, unsigned long arg4, unsigned long arg5) { - unsigned long hartid, cpuid, hmask = 0, hbase = 0; + unsigned long hartid, cpuid, hmask = 0, hbase = 0, htop = 0; int result; if (!cpu_mask || cpumask_empty(cpu_mask)) @@ -353,16 +364,26 @@ static int __sbi_rfence_v02(int fid, const struct cpumask *cpu_mask, for_each_cpu(cpuid, cpu_mask) { hartid = cpuid_to_hartid_map(cpuid); - if (hmask && ((hbase + BITS_PER_LONG) <= hartid)) { - result = __sbi_rfence_v02_call(fid, hmask, hbase, - start, size, arg4, arg5); - if (result) - return result; - hmask = 0; - hbase = 0; + if (hmask) { + if (hartid + BITS_PER_LONG <= htop || + hbase + BITS_PER_LONG <= hartid) { + result = __sbi_rfence_v02_call(fid, hmask, + hbase, start, size, arg4, arg5); + if (result) + return result; + hmask = 0; + } else if (hartid < hbase) { + /* shift the mask to fit lower hartid */ + hmask <<= hbase - hartid; + hbase = hartid; + } } - if (!hmask) + if (!hmask) { hbase = hartid; + htop = hartid; + } else if (hartid > htop) { + htop = hartid; + } hmask |= BIT(hartid - hbase); } |