From 82b35b5043c141c86c60e069219213b41f4bb33c Mon Sep 17 00:00:00 2001 From: Jinjie Ruan Date: Mon, 8 Jul 2024 11:28:46 +0800 Subject: [PATCH] riscv: Fix fp alignment bug in perf_callchain_user() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 22ab08955ea13be04a8efd20cc30890e0afaa49c ] The standard RISC-V calling convention said: "The stack grows downward and the stack pointer is always kept 16-byte aligned". So perf_callchain_user() should check whether 16-byte aligned for fp. Link: https://riscv.org/wp-content/uploads/2015/01/riscv-calling.pdf Fixes: dbeb90b0c1eb ("riscv: Add perf callchain support") Signed-off-by: Jinjie Ruan Cc: Björn Töpel Link: https://lore.kernel.org/r/20240708032847.2998158-2-ruanjinjie@huawei.com Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin --- arch/riscv/kernel/perf_callchain.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c index fb02811df..3c0a43cb1 100755 --- a/arch/riscv/kernel/perf_callchain.c +++ b/arch/riscv/kernel/perf_callchain.c @@ -71,7 +71,7 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry, perf_callchain_store(entry, regs->epc); fp = user_backtrace(entry, fp, regs->ra); - while (fp && !(fp & 0x3) && entry->nr < entry->max_stack) + while (fp && !(fp & 0x7) && entry->nr < entry->max_stack) fp = user_backtrace(entry, fp, 0); }