From db5a21f2dd62f83bd3dcea6f5a5286d3e64586fd Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Mon, 14 Mar 2022 17:10:45 -0700 Subject: [PATCH] x86/mm: Cleanup the control_va_addr_alignment() __setup handler [ Upstream commit 1ef64b1e89e6d4018da46e08ffc32779a31160c7 ] Clean up control_va_addr_alignment(): a. Make '=' required instead of optional (as documented). b. Print a warning if an invalid option value is used. c. Return 1 from the __setup handler when an invalid option value is used. This prevents the kernel from polluting init's (limited) environment space with the entire string. Fixes: dfb09f9b7ab0 ("x86, amd: Avoid cache aliasing penalties on AMD family 15h") Reported-by: Igor Zhbanov Signed-off-by: Randy Dunlap Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Link: https://lore.kernel.org/r/20220315001045.7680-1-rdunlap@infradead.org Signed-off-by: Sasha Levin --- arch/x86/kernel/sys_x86_64.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c index f7476ce23b6e..42e31358a9d3 100644 --- a/arch/x86/kernel/sys_x86_64.c +++ b/arch/x86/kernel/sys_x86_64.c @@ -70,9 +70,6 @@ static int __init control_va_addr_alignment(char *str) if (*str == 0) return 1; - if (*str == '=') - str++; - if (!strcmp(str, "32")) va_align.flags = ALIGN_VA_32; else if (!strcmp(str, "64")) @@ -82,11 +79,11 @@ static int __init control_va_addr_alignment(char *str) else if (!strcmp(str, "on")) va_align.flags = ALIGN_VA_32 | ALIGN_VA_64; else - return 0; + pr_warn("invalid option value: 'align_va_addr=%s'\n", str); return 1; } -__setup("align_va_addr", control_va_addr_alignment); +__setup("align_va_addr=", control_va_addr_alignment); SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len, unsigned long, prot, unsigned long, flags,