diff options
author | Hui Li <lihui@loongson.cn> | 2024-06-21 05:18:40 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-06-27 14:52:27 +0300 |
commit | c8648159339b8b8d12868a1c294cbf451e85062e (patch) | |
tree | f553673e2f5853f32062aac381a4aca8fb530825 /arch | |
parent | 5def908dad5ca66c60588d55c5473cb4fb1d07b2 (diff) | |
download | linux-c8648159339b8b8d12868a1c294cbf451e85062e.tar.xz |
LoongArch: Fix watchpoint setting error
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@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>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/loongarch/include/asm/hw_breakpoint.h | 2 | ||||
-rw-r--r-- | arch/loongarch/kernel/hw_breakpoint.c | 19 | ||||
-rw-r--r-- | arch/loongarch/kernel/ptrace.c | 32 |
3 files changed, 21 insertions, 32 deletions
diff --git a/arch/loongarch/include/asm/hw_breakpoint.h b/arch/loongarch/include/asm/hw_breakpoint.h index 21447fb1efc7..a8ce580f4fc6 100644 --- 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, diff --git a/arch/loongarch/kernel/hw_breakpoint.c b/arch/loongarch/kernel/hw_breakpoint.c index fc55c4de2a11..950b2b8a82ee 100644 --- 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 arch_hw_breakpoint *hw) * 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_hw_breakpoint_ctrl ctrl, 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_event *bp, 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; } diff --git a/arch/loongarch/kernel/ptrace.c b/arch/loongarch/kernel/ptrace.c index c114c5ef1332..16b756c6049b 100644 --- a/arch/loongarch/kernel/ptrace.c +++ b/arch/loongarch/kernel/ptrace.c @@ -494,28 +494,14 @@ static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type, 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 int note_type, 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; |