[PATCH] riscv: Invalid instruction cache after copy the xol area

From: Po-Kai Chi
Date: Wed May 18 2022 - 04:18:30 EST


We need to invalid the relevant instruction cache after
copying the xol area, to ensure the changes takes effect.

Signed-off-by: Po-Kai Chi <po-kai.chi@xxxxxxxxxx>
---
arch/riscv/kernel/probes/uprobes.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/kernel/probes/uprobes.c b/arch/riscv/kernel/probes/uprobes.c
index 7a057b5f0adc..9d52beeac73c 100644
--- a/arch/riscv/kernel/probes/uprobes.c
+++ b/arch/riscv/kernel/probes/uprobes.c
@@ -165,6 +165,7 @@ void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
/* Initialize the slot */
void *kaddr = kmap_atomic(page);
void *dst = kaddr + (vaddr & ~PAGE_MASK);
+ unsigned long addr = (unsigned long)dst;

memcpy(dst, src, len);

@@ -177,10 +178,9 @@ void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
kunmap_atomic(kaddr);

/*
- * We probably need flush_icache_user_page() but it needs vma.
- * This should work on most of architectures by default. If
- * architecture needs to do something different it can define
- * its own version of the function.
+ * Flush both I/D cache to ensure instruction modification
+ * takes effect.
*/
flush_dcache_page(page);
+ flush_icache_range(addr, addr + len);
}
--
2.36.1