From 2727c43f8dcef9f6a0c3c117e30d00de145bde11 Mon Sep 17 00:00:00 2001 From: Marcos Oduardo Date: Mon, 23 Feb 2026 01:11:59 +0100 Subject: [PATCH] lib: sbi: Fix undefined behavior in signed shifts in sbi_hart.c MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit UBSan detected undefined behavior in sbi_hart.c and sbi_fwft.c (in the case of sbi_fwft.c, the bug comes from a macro call defined at sbi_ecall_interface.h) caused by shifting a signed integer into the sign bit (1 << 31) This can be fixed by using the 1UL literal, ensuring defined arithmetic. Please let me know if there’s any other most suitable solution for this bug. Signed-off-by: Marcos Oduardo Reviewed-by: Anup Patel Link: https://lore.kernel.org/r/20260223001202.284612-1-marcos.oduardo@gmail.com Signed-off-by: Anup Patel --- include/sbi/sbi_ecall_interface.h | 2 +- lib/sbi/sbi_hart.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/include/sbi/sbi_ecall_interface.h b/include/sbi/sbi_ecall_interface.h index 76624e3f..9a776f79 100644 --- a/include/sbi/sbi_ecall_interface.h +++ b/include/sbi/sbi_ecall_interface.h @@ -144,7 +144,7 @@ enum sbi_fwft_feature_t { SBI_FWFT_GLOBAL_PLATFORM_END = 0xffffffff, }; -#define SBI_FWFT_GLOBAL_FEATURE_BIT (1 << 31) +#define SBI_FWFT_GLOBAL_FEATURE_BIT (1UL << 31) #define SBI_FWFT_PLATFORM_FEATURE_BIT (1 << 30) #define SBI_FWFT_SET_FLAG_LOCK (1 << 0) diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c index 60e95bca..99e13990 100644 --- a/lib/sbi/sbi_hart.c +++ b/lib/sbi/sbi_hart.c @@ -70,7 +70,7 @@ static void mstatus_init(struct sbi_scratch *scratch) */ mhpmevent_init_val |= (MHPMEVENT_OF | MHPMEVENT_MINH); for (cidx = 0; cidx <= 28; cidx++) { - if (!(mhpm_mask & 1 << (cidx + 3))) + if (!(mhpm_mask & 1UL << (cidx + 3))) continue; #if __riscv_xlen == 32 csr_write_num(CSR_MHPMEVENT3 + cidx,