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| author | Radim Krčmář <rkrcmar@ventanamicro.com> | 2025-04-29 16:25:46 +0200 |
|---|---|---|
| committer | Anup Patel <anup@brainfault.org> | 2025-04-30 10:14:26 +0530 |
| commit | 6b877fb53b8da84c69f0832c7f2a343239ba609e (patch) | |
| tree | fa0396b2e47ea5cea2241f13cb967e9e97031c15 | |
| parent | 009f77a9f06bcb5a3a6252b3333171adb8c84512 (diff) | |
| download | opensbi-6b877fb53b8da84c69f0832c7f2a343239ba609e.zip opensbi-6b877fb53b8da84c69f0832c7f2a343239ba609e.tar.gz opensbi-6b877fb53b8da84c69f0832c7f2a343239ba609e.tar.bz2 | |
lib: sbi_hart: reset sstateen and hstateen
Not resetting sstateen is a potential security hole, because U might be
able to access state that S does not properly context-switch.
Similar for hstateen with VS and HS.
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Radim Krčmář <rkrcmar@ventanamicro.com>
Link: https://lore.kernel.org/r/20250429142549.3673976-6-rkrcmar@ventanamicro.com
Signed-off-by: Anup Patel <anup@brainfault.org>
| -rw-r--r-- | lib/sbi/sbi_hart.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c index 5ea7328..bdf66ef 100644 --- a/lib/sbi/sbi_hart.c +++ b/lib/sbi/sbi_hart.c @@ -111,6 +111,12 @@ static void mstatus_init(struct sbi_scratch *scratch) mstateen_val &= ~SMSTATEEN0_CTR; csr_write64(CSR_MSTATEEN0, mstateen_val); + + if (misa_extension('S')) + csr_write(CSR_SSTATEEN0, 0); + + if (misa_extension('H')) + csr_write64(CSR_HSTATEEN0, (uint64_t)0); } if (sbi_hart_priv_version(scratch) >= SBI_HART_PRIV_VER_1_12) { |