This is a note to let you know that I've just added the patch titled
powerpc/watchpoint: Fix quadword instruction handling on p10 predecessors
to the 5.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-watchpoint-fix-quadword-instruction-handling.patch
and it can be found in the queue-5.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e896e6ea4b0323a1ebb95e8e4361c01fc456d272
Author: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxx>
Date: Wed Sep 2 09:59:38 2020 +0530
powerpc/watchpoint: Fix quadword instruction handling on p10 predecessors
[ Upstream commit 4759c11ed20454b7b36db4ec15f7d5aa1519af4a ]
On p10 predecessors, watchpoint with quadword access is compared at
quadword length. If the watch range is doubleword or less than that
in a first half of quadword aligned 16 bytes, and if there is any
unaligned quadword access which will access only the 2nd half, the
handler should consider it as extraneous and emulate/single-step it
before continuing.
Fixes: 74c6881019b7 ("powerpc/watchpoint: Prepare handler to handle more than one watchpoint")
Reported-by: Pedro Miraglia Franco de Carvalho <pedromfc@xxxxxxxxxxxxx>
Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200902042945.129369-2-ravi.bangoria@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
index cb424799da0dc..5a00da670a407 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h
@@ -40,6 +40,7 @@ struct arch_hw_breakpoint {
#else
#define HW_BREAKPOINT_SIZE 0x8
#endif
+#define HW_BREAKPOINT_SIZE_QUADWORD 0x10
#define DABR_MAX_LEN 8
#define DAWR_MAX_LEN 512
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index c55e67bab2710..f39e86d751144 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -519,9 +519,17 @@ static bool ea_hw_range_overlaps(unsigned long ea, int size,
struct arch_hw_breakpoint *info)
{
unsigned long hw_start_addr, hw_end_addr;
+ unsigned long align_size = HW_BREAKPOINT_SIZE;
- hw_start_addr = ALIGN_DOWN(info->address, HW_BREAKPOINT_SIZE);
- hw_end_addr = ALIGN(info->address + info->len, HW_BREAKPOINT_SIZE);
+ /*
+ * On p10 predecessors, quadword is handle differently then
+ * other instructions.
+ */
+ if (!cpu_has_feature(CPU_FTR_ARCH_31) && size == 16)
+ align_size = HW_BREAKPOINT_SIZE_QUADWORD;
+
+ hw_start_addr = ALIGN_DOWN(info->address, align_size);
+ hw_end_addr = ALIGN(info->address + info->len, align_size);
return ((ea < hw_end_addr) && (ea + size > hw_start_addr));
}
