@@ -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);
}
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: Emil Renner Berthing <kernel@esmil.dk> Tested-by: Atish Patra <atishp@rivosinc.com> --- v2: - Add Reviewed-by, Tested-by. --- arch/riscv/kernel/sbi.c | 57 ++++++++++++++++++++++++++++------------- 1 file changed, 39 insertions(+), 18 deletions(-)