Patch #1 fixes a bug when watchpoint is created with ptrace
PPC_PTRACE_SETHWDEBUG and CONFIG_HAVE_HW_BREAKPOINT=N.
patch #2 introduce new feature bit
PPC_DEBUG_FEATURE_DATA_BP_ARCH_31 which will be set when
running on ISA 3.1 compliant machine.
v2: https://lore.kernel.org/r/[email protected]
v2->v3:
- #1: is new
- #2: Set PPC_DEBUG_FEATURE_DATA_BP_ARCH_31 unconditionally
while running on p10.
- Rebased to powerpc/next (cf1ae052e073)
Ravi Bangoria (2):
powerpc/watchpoint/ptrace: Fix SETHWDEBUG when
CONFIG_HAVE_HW_BREAKPOINT=N
powerpc/watchpoint/ptrace: Introduce PPC_DEBUG_FEATURE_DATA_BP_ARCH_31
Documentation/powerpc/ptrace.rst | 1 +
arch/powerpc/include/uapi/asm/ptrace.h | 1 +
arch/powerpc/kernel/ptrace/ptrace-noadv.c | 4 +++-
3 files changed, 5 insertions(+), 1 deletion(-)
--
2.26.2
PPC_DEBUG_FEATURE_DATA_BP_ARCH_31 can be used to determine whether
we are running on an ISA 3.1 compliant machine. Which is needed to
determine DAR behaviour, 512 byte boundary limit etc. This was
requested by Pedro Miraglia Franco de Carvalho for extending
watchpoint features in gdb. Note that availability of 2nd DAWR is
independent of this flag and should be checked using
ppc_debug_info->num_data_bps.
Signed-off-by: Ravi Bangoria <[email protected]>
---
Documentation/powerpc/ptrace.rst | 1 +
arch/powerpc/include/uapi/asm/ptrace.h | 1 +
arch/powerpc/kernel/ptrace/ptrace-noadv.c | 2 ++
3 files changed, 4 insertions(+)
diff --git a/Documentation/powerpc/ptrace.rst b/Documentation/powerpc/ptrace.rst
index 864d4b6dddd1..77725d69eb4a 100644
--- a/Documentation/powerpc/ptrace.rst
+++ b/Documentation/powerpc/ptrace.rst
@@ -46,6 +46,7 @@ features will have bits indicating whether there is support for::
#define PPC_DEBUG_FEATURE_DATA_BP_RANGE 0x4
#define PPC_DEBUG_FEATURE_DATA_BP_MASK 0x8
#define PPC_DEBUG_FEATURE_DATA_BP_DAWR 0x10
+ #define PPC_DEBUG_FEATURE_DATA_BP_ARCH_31 0x20
2. PTRACE_SETHWDEBUG
diff --git a/arch/powerpc/include/uapi/asm/ptrace.h b/arch/powerpc/include/uapi/asm/ptrace.h
index f5f1ccc740fc..7004cfea3f5f 100644
--- a/arch/powerpc/include/uapi/asm/ptrace.h
+++ b/arch/powerpc/include/uapi/asm/ptrace.h
@@ -222,6 +222,7 @@ struct ppc_debug_info {
#define PPC_DEBUG_FEATURE_DATA_BP_RANGE 0x0000000000000004
#define PPC_DEBUG_FEATURE_DATA_BP_MASK 0x0000000000000008
#define PPC_DEBUG_FEATURE_DATA_BP_DAWR 0x0000000000000010
+#define PPC_DEBUG_FEATURE_DATA_BP_ARCH_31 0x0000000000000020
#ifndef __ASSEMBLY__
diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
index bf94ab837735..d5be73ab9e74 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-noadv.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
@@ -57,6 +57,8 @@ void ppc_gethwdinfo(struct ppc_debug_info *dbginfo)
} else {
dbginfo->features = 0;
}
+ if (cpu_has_feature(CPU_FTR_ARCH_31))
+ dbginfo->features |= PPC_DEBUG_FEATURE_DATA_BP_ARCH_31;
}
int ptrace_get_debugreg(struct task_struct *child, unsigned long addr,
--
2.26.2
When kernel is compiled with CONFIG_HAVE_HW_BREAKPOINT=N, user can
still create watchpoint using PPC_PTRACE_SETHWDEBUG, with limited
functionalities. But, such watchpoints are never firing because of
the missing privilege settings. Fix that.
Reported-by: Pedro Miraglia Franco de Carvalho <[email protected]>
Suggested-by: Pedro Miraglia Franco de Carvalho <[email protected]>
Signed-off-by: Ravi Bangoria <[email protected]>
---
arch/powerpc/kernel/ptrace/ptrace-noadv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
index 697c7e4b5877..bf94ab837735 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-noadv.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
@@ -217,7 +217,7 @@ long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_inf
return -EIO;
brk.address = ALIGN_DOWN(bp_info->addr, HW_BREAKPOINT_SIZE);
- brk.type = HW_BRK_TYPE_TRANSLATE;
+ brk.type = HW_BRK_TYPE_TRANSLATE | HW_BRK_TYPE_USER;
brk.len = DABR_MAX_LEN;
if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
brk.type |= HW_BRK_TYPE_READ;
--
2.26.2