[PATCH] riscv/mm: Add handling for VM_FAULT_SIGSEGV in mm_fault_error()

From: Zhe Qiao
Date: Tue Jul 30 2024 - 23:27:04 EST


Add processing for VM_CAULT_SIGSEGV to mm_fault_error () to avoid
direct execution of BUG().

Fixes: 07037db5d479 ("RISC-V: Paging and MMU")
Signed-off-by: Zhe Qiao <qiaozhe@xxxxxxxxxxx>
---
arch/riscv/mm/fault.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 5224f3733802..a9f2b4af8f3f 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -61,26 +61,27 @@ static inline void no_context(struct pt_regs *regs, unsigned long addr)

static inline void mm_fault_error(struct pt_regs *regs, unsigned long addr, vm_fault_t fault)
{
+ if (!user_mode(regs)) {
+ no_context(regs, addr);
+ return;
+ }
+
if (fault & VM_FAULT_OOM) {
/*
* We ran out of memory, call the OOM killer, and return the userspace
* (which will retry the fault, or kill us if we got oom-killed).
*/
- if (!user_mode(regs)) {
- no_context(regs, addr);
- return;
- }
pagefault_out_of_memory();
return;
} else if (fault & (VM_FAULT_SIGBUS | VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE)) {
/* Kernel mode? Handle exceptions or die */
- if (!user_mode(regs)) {
- no_context(regs, addr);
- return;
- }
do_trap(regs, SIGBUS, BUS_ADRERR, addr);
return;
+ } else if (fault & VM_FAULT_SIGSEGV) {
+ do_trap(regs, SIGSEGV, SEGV_MAPERR, addr);
+ return;
}
+
BUG();
}

--
2.43.0