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")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
---
arch/x86/kernel/sys_x86_64.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
--- lnx-517-rc8.orig/arch/x86/kernel/sys_x86_64.c
+++ lnx-517-rc8/arch/x86/kernel/sys_x86_64.c
@@ -68,9 +68,6 @@ static int __init control_va_addr_alignm
if (*str == 0)
return 1;
- if (*str == '=')
- str++;
-
if (!strcmp(str, "32"))
va_align.flags = ALIGN_VA_32;
else if (!strcmp(str, "64"))
@@ -80,11 +77,11 @@ static int __init control_va_addr_alignm
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,