From 3190ecbfeeb2ab17778887ce3fa964615d6460fd Mon Sep 17 00:00:00 2001
From: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Date: Thu, 23 Jul 2020 14:38:04 +0530
Subject: [PATCH] powerpc/watchpoint: Fix 512 byte boundary limit
References: jsc#SLE-12936
Patch-mainline: v5.9-rc1
Git-commit: 3190ecbfeeb2ab17778887ce3fa964615d6460fd
Milton Miller reported that we are aligning start and end address to
wrong size SZ_512M. It should be SZ_512. Fix that.
While doing this change I also found a case where ALIGN() comparison
fails. Within a given aligned range, ALIGN() of two addresses does not
match when start address is pointing to the first byte and end address
is pointing to any other byte except the first one. But that's not true
for ALIGN_DOWN(). ALIGN_DOWN() of any two addresses within that range
will always point to the first byte. So use ALIGN_DOWN() instead of
ALIGN().
Fixes: e68ef121c1f4 ("powerpc/watchpoint: Use builtin ALIGN*() macros")
Reported-by: Milton Miller <miltonm@us.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Tested-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200723090813.303838-2-ravi.bangoria@linux.ibm.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/kernel/hw_breakpoint.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 0000daf0e1da..031e6defc08e 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -419,7 +419,7 @@ static int hw_breakpoint_validate_len(struct arch_hw_breakpoint *hw)
if (dawr_enabled()) {
max_len = DAWR_MAX_LEN;
/* DAWR region can't cross 512 bytes boundary */
- if (ALIGN(start_addr, SZ_512M) != ALIGN(end_addr - 1, SZ_512M))
+ if (ALIGN_DOWN(start_addr, SZ_512) != ALIGN_DOWN(end_addr - 1, SZ_512))
return -EINVAL;
} else if (IS_ENABLED(CONFIG_PPC_8xx)) {
/* 8xx can setup a range without limitation */
--
2.26.2