linux-kernel - [PATCH 2/5] x86: c_p_a clflush_cache

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 31 Jan 2008 15:36:02 +0800
From:	"Huang, Ying" <ying.huang@...el.com>
To:	Ingo Molnar <mingo@...hat.com>, "H. Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>, Andi Kleen <ak@...e.de>
Cc:	linux-kernel@...r.kernel.org
Subject: [PATCH 2/5] x86: c_p_a clflush_cache_range fix

Because in i386 early boot stage, boot_cpu_data may be not available,
which makes clflush_cach_range() into infinite loop, which is called
by change_page_attr(). This patch fixes this by providing a default
clflush_size of 64. But the better method may be providing a
early_identify_cpu() for i386.

Signed-off-by: Huang Ying <ying.huang@...el.com>

---
 arch/x86/mm/pageattr.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -36,11 +36,14 @@ within(unsigned long addr, unsigned long
  */
 void clflush_cache_range(void *vaddr, unsigned int size)
 {
+	int clflush_size;
 	void *vend = vaddr + size - 1;
 
 	mb();
 
-	for (; vaddr < vend; vaddr += boot_cpu_data.x86_clflush_size)
+	/* In boot stage, boot_cpu_data may be not available */
+	clflush_size = boot_cpu_data.x86_clflush_size ? : 64;
+	for (; vaddr < vend; vaddr += clflush_size)
 		clflush(vaddr);
 	/*
 	 * Flush any possible final partial cacheline:

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/