From: Hui Li <lihui@xxxxxxxxxxx>
commit f63a47b34b140ed1ca39d7e4bd4f1cdc617fc316 upstream.
In the current code, when debugging the following code using gdb,
"invalid argument ..." message will be displayed.
lihui@bogon:~$ cat test.c
#include <stdio.h>
int a = 0;
int main()
{
a = 1;
return 0;
}
lihui@bogon:~$ gcc -g test.c -o test
lihui@bogon:~$ gdb test
...
(gdb) watch a
Hardware watchpoint 1: a
(gdb) r
...
Invalid argument setting hardware debug registers
There are mainly two types of issues.
1. Some incorrect judgment condition existed in user_watch_state
argument parsing, causing -EINVAL to be returned.
When setting up a watchpoint, gdb uses the ptrace interface,
ptrace(PTRACE_SETREGSET, tid, NT_LOONGARCH_HW_WATCH, (void *) &iov)).
Register values in user_watch_state as follows:
addr[0] = 0x0, mask[0] = 0x0, ctrl[0] = 0x0
addr[1] = 0x0, mask[1] = 0x0, ctrl[1] = 0x0
addr[2] = 0x0, mask[2] = 0x0, ctrl[2] = 0x0
addr[3] = 0x0, mask[3] = 0x0, ctrl[3] = 0x0
addr[4] = 0x0, mask[4] = 0x0, ctrl[4] = 0x0
addr[5] = 0x0, mask[5] = 0x0, ctrl[5] = 0x0
addr[6] = 0x0, mask[6] = 0x0, ctrl[6] = 0x0
addr[7] = 0x12000803c, mask[7] = 0x0, ctrl[7] = 0x610
In arch_bp_generic_fields(), return -EINVAL when ctrl.len is
LOONGARCH_BREAKPOINT_LEN_8(0b00). So delete the incorrect judgment here.
In ptrace_hbp_fill_attr_ctrl(), when note_type is NT_LOONGARCH_HW_WATCH
and ctrl[0] == 0x0, if ((type & HW_BREAKPOINT_RW) != type) will return
-EINVAL. Here ctrl.type should be set based on note_type, and unnecessary
judgments can be removed.
2. The watchpoint argument was not set correctly due to unnecessary
offset and alignment_mask.
Modify ptrace_hbp_fill_attr_ctrl() and hw_breakpoint_arch_parse(), which
ensure the watchpont argument is set correctly.
All changes according to the LoongArch Reference Manual:
https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#control-and-status-registers-related-to-watchpoints
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Hui Li <lihui@xxxxxxxxxxx>
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/loongarch/include/asm/hw_breakpoint.h | 2 -
arch/loongarch/kernel/hw_breakpoint.c | 19 ++++-------------
arch/loongarch/kernel/ptrace.c | 32 +++++++++++++----------------
3 files changed, 21 insertions(+), 32 deletions(-)
--- a/arch/loongarch/include/asm/hw_breakpoint.h
+++ b/arch/loongarch/include/asm/hw_breakpoint.h
@@ -101,7 +101,7 @@ struct perf_event;
struct perf_event_attr;
extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
- int *gen_len, int *gen_type, int *offset);
+ int *gen_len, int *gen_type);
extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
extern int hw_breakpoint_arch_parse(struct perf_event *bp,
const struct perf_event_attr *attr,
--- a/arch/loongarch/kernel/hw_breakpoint.c
+++ b/arch/loongarch/kernel/hw_breakpoint.c
@@ -283,7 +283,7 @@ int arch_check_bp_in_kernelspace(struct
* to generic breakpoint descriptions.
*/
int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
- int *gen_len, int *gen_type, int *offset)
+ int *gen_len, int *gen_type)
{
/* Type */
switch (ctrl.type) {
@@ -303,11 +303,6 @@ int arch_bp_generic_fields(struct arch_h
return -EINVAL;
}
- if (!ctrl.len)
- return -EINVAL;
-
- *offset = __ffs(ctrl.len);
-
/* Len */
switch (ctrl.len) {
case LOONGARCH_BREAKPOINT_LEN_1:
@@ -386,21 +381,17 @@ int hw_breakpoint_arch_parse(struct perf
struct arch_hw_breakpoint *hw)
{
int ret;
- u64 alignment_mask, offset;
+ u64 alignment_mask;
/* Build the arch_hw_breakpoint. */
ret = arch_build_bp_info(bp, attr, hw);
if (ret)
return ret;
- if (hw->ctrl.type != LOONGARCH_BREAKPOINT_EXECUTE)
- alignment_mask = 0x7;
- else
+ if (hw->ctrl.type == LOONGARCH_BREAKPOINT_EXECUTE) {
alignment_mask = 0x3;
- offset = hw->address & alignment_mask;
-
- hw->address &= ~alignment_mask;
- hw->ctrl.len <<= offset;
+ hw->address &= ~alignment_mask;
+ }
return 0;
}
--- a/arch/loongarch/kernel/ptrace.c
+++ b/arch/loongarch/kernel/ptrace.c
@@ -494,28 +494,14 @@ static int ptrace_hbp_fill_attr_ctrl(uns
struct arch_hw_breakpoint_ctrl ctrl,
struct perf_event_attr *attr)
{
- int err, len, type, offset;
+ int err, len, type;
- err = arch_bp_generic_fields(ctrl, &len, &type, &offset);
+ err = arch_bp_generic_fields(ctrl, &len, &type);
if (err)
return err;
- switch (note_type) {
- case NT_LOONGARCH_HW_BREAK:
- if ((type & HW_BREAKPOINT_X) != type)
- return -EINVAL;
- break;
- case NT_LOONGARCH_HW_WATCH:
- if ((type & HW_BREAKPOINT_RW) != type)
- return -EINVAL;
- break;
- default:
- return -EINVAL;
- }
-
attr->bp_len = len;
attr->bp_type = type;
- attr->bp_addr += offset;
return 0;
}
@@ -609,7 +595,19 @@ static int ptrace_hbp_set_ctrl(unsigned
return PTR_ERR(bp);
attr = bp->attr;
- decode_ctrl_reg(uctrl, &ctrl);
+
+ switch (note_type) {
+ case NT_LOONGARCH_HW_BREAK:
+ ctrl.type = LOONGARCH_BREAKPOINT_EXECUTE;
+ ctrl.len = LOONGARCH_BREAKPOINT_LEN_4;
+ break;
+ case NT_LOONGARCH_HW_WATCH:
+ decode_ctrl_reg(uctrl, &ctrl);
+ break;
+ default:
+ return -EINVAL;
+ }
+
err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
if (err)
return err;
Patches currently in stable-queue which might be from lihui@xxxxxxxxxxx are
queue-6.9/loongarch-fix-watchpoint-setting-error.patch
queue-6.9/loongarch-trigger-user-space-watchpoints-correctly.patch
queue-6.9/loongarch-fix-multiple-hardware-watchpoint-issues.patch
