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LoongArch: Fix watchpoint setting error
commit f63a47b34b
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@vger.kernel.org
Signed-off-by: Hui Li <lihui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
450df994f3
commit
4b26f9ace3
3 changed files with 21 additions and 32 deletions
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@ -101,7 +101,7 @@ struct perf_event;
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struct perf_event_attr;
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extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
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int *gen_len, int *gen_type, int *offset);
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int *gen_len, int *gen_type);
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extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
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extern int hw_breakpoint_arch_parse(struct perf_event *bp,
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const struct perf_event_attr *attr,
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@ -283,7 +283,7 @@ int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw)
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* to generic breakpoint descriptions.
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*/
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int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
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int *gen_len, int *gen_type, int *offset)
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int *gen_len, int *gen_type)
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{
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/* Type */
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switch (ctrl.type) {
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@ -303,11 +303,6 @@ int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
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return -EINVAL;
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}
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if (!ctrl.len)
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return -EINVAL;
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*offset = __ffs(ctrl.len);
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/* Len */
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switch (ctrl.len) {
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case LOONGARCH_BREAKPOINT_LEN_1:
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@ -386,21 +381,17 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
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struct arch_hw_breakpoint *hw)
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{
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int ret;
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u64 alignment_mask, offset;
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u64 alignment_mask;
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/* Build the arch_hw_breakpoint. */
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ret = arch_build_bp_info(bp, attr, hw);
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if (ret)
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return ret;
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if (hw->ctrl.type != LOONGARCH_BREAKPOINT_EXECUTE)
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alignment_mask = 0x7;
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else
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if (hw->ctrl.type == LOONGARCH_BREAKPOINT_EXECUTE) {
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alignment_mask = 0x3;
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offset = hw->address & alignment_mask;
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hw->address &= ~alignment_mask;
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hw->ctrl.len <<= offset;
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hw->address &= ~alignment_mask;
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}
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return 0;
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}
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@ -494,28 +494,14 @@ static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
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struct arch_hw_breakpoint_ctrl ctrl,
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struct perf_event_attr *attr)
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{
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int err, len, type, offset;
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int err, len, type;
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err = arch_bp_generic_fields(ctrl, &len, &type, &offset);
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err = arch_bp_generic_fields(ctrl, &len, &type);
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if (err)
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return err;
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switch (note_type) {
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case NT_LOONGARCH_HW_BREAK:
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if ((type & HW_BREAKPOINT_X) != type)
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return -EINVAL;
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break;
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case NT_LOONGARCH_HW_WATCH:
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if ((type & HW_BREAKPOINT_RW) != type)
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return -EINVAL;
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break;
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default:
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return -EINVAL;
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}
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attr->bp_len = len;
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attr->bp_type = type;
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attr->bp_addr += offset;
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return 0;
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}
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@ -609,7 +595,19 @@ static int ptrace_hbp_set_ctrl(unsigned int note_type,
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return PTR_ERR(bp);
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attr = bp->attr;
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decode_ctrl_reg(uctrl, &ctrl);
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switch (note_type) {
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case NT_LOONGARCH_HW_BREAK:
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ctrl.type = LOONGARCH_BREAKPOINT_EXECUTE;
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ctrl.len = LOONGARCH_BREAKPOINT_LEN_4;
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break;
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case NT_LOONGARCH_HW_WATCH:
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decode_ctrl_reg(uctrl, &ctrl);
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break;
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default:
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return -EINVAL;
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}
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err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
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if (err)
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return err;
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