6.15-stable review patch. If anyone has any objections, please let me know.
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From: Cyril Bur cyrilbur@tenstorrent.com
commit 265d6aba165c500389c80d394ac247460c443ef5 upstream.
During switch to csrs will OR the value of the register into the corresponding csr. In this case we're only interested in restoring the SUM bit not the entire register.
Signed-off-by: Cyril Bur cyrilbur@tenstorrent.com Link: https://lore.kernel.org/r/20250522160954.429333-1-cyrilbur@tenstorrent.com Co-developed-by: Alexandre Ghiti alexghiti@rivosinc.com Signed-off-by: Alexandre Ghiti alexghiti@rivosinc.com Fixes: 788aa64c01f1 ("riscv: save the SR_SUM status over switches") Link: https://lore.kernel.org/r/20250602121543.1544278-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt palmer@dabbelt.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/riscv/include/asm/processor.h | 2 +- arch/riscv/kernel/asm-offsets.c | 6 +++--- arch/riscv/kernel/entry.S | 9 +++++---- 3 files changed, 9 insertions(+), 8 deletions(-)
--- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -103,7 +103,7 @@ struct thread_struct { struct __riscv_d_ext_state fstate; unsigned long bad_cause; unsigned long envcfg; - unsigned long status; + unsigned long sum; u32 riscv_v_flags; u32 vstate_ctrl; struct __riscv_v_ext_state vstate; --- a/arch/riscv/kernel/asm-offsets.c +++ b/arch/riscv/kernel/asm-offsets.c @@ -34,7 +34,7 @@ void asm_offsets(void) OFFSET(TASK_THREAD_S9, task_struct, thread.s[9]); OFFSET(TASK_THREAD_S10, task_struct, thread.s[10]); OFFSET(TASK_THREAD_S11, task_struct, thread.s[11]); - OFFSET(TASK_THREAD_STATUS, task_struct, thread.status); + OFFSET(TASK_THREAD_SUM, task_struct, thread.sum);
OFFSET(TASK_TI_CPU, task_struct, thread_info.cpu); OFFSET(TASK_TI_PREEMPT_COUNT, task_struct, thread_info.preempt_count); @@ -347,8 +347,8 @@ void asm_offsets(void) offsetof(struct task_struct, thread.s[11]) - offsetof(struct task_struct, thread.ra) ); - DEFINE(TASK_THREAD_STATUS_RA, - offsetof(struct task_struct, thread.status) + DEFINE(TASK_THREAD_SUM_RA, + offsetof(struct task_struct, thread.sum) - offsetof(struct task_struct, thread.ra) );
--- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -399,14 +399,15 @@ SYM_FUNC_START(__switch_to) REG_S s11, TASK_THREAD_S11_RA(a3)
/* save the user space access flag */ - li s0, SR_SUM - csrr s1, CSR_STATUS - REG_S s1, TASK_THREAD_STATUS_RA(a3) + csrr s0, CSR_STATUS + REG_S s0, TASK_THREAD_SUM_RA(a3)
/* Save the kernel shadow call stack pointer */ scs_save_current /* Restore context from next->thread */ - REG_L s0, TASK_THREAD_STATUS_RA(a4) + REG_L s0, TASK_THREAD_SUM_RA(a4) + li s1, SR_SUM + and s0, s0, s1 csrs CSR_STATUS, s0 REG_L ra, TASK_THREAD_RA_RA(a4) REG_L sp, TASK_THREAD_SP_RA(a4)