Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'powerpc-5.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
- Fix breakage of strace (and other ptracers etc.) when using the new
scv ABI (Power9 or later with glibc >= 2.33).
- Fix early_ioremap() on 64-bit, which broke booting on some machines.
Thanks to Dmitry V. Levin, Nicholas Piggin, Alexey Kardashevskiy, and
Christophe Leroy.
* tag 'powerpc-5.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/64s/syscall: Fix ptrace syscall info with scv syscalls
powerpc/64s/syscall: Use pt_regs.trap to distinguish syscall ABI difference between sc and scv syscalls
powerpc: Fix early setup to make early_ioremap() work
+82
-46
+10
Documentation/powerpc/syscall64-abi.rst
+10
Documentation/powerpc/syscall64-abi.rst
···
109
109
110
110
scv 0 syscalls will always behave as PPC_FEATURE2_HTM_NOSC.
111
111
112
+
ptrace
113
+
------
114
+
When ptracing system calls (PTRACE_SYSCALL), the pt_regs.trap value contains
115
+
the system call type that can be used to distinguish between sc and scv 0
116
+
system calls, and the different register conventions can be accounted for.
117
+
118
+
If the value of (pt_regs.trap & 0xfff0) is 0xc00 then the system call was
119
+
performed with the sc instruction, if it is 0x3000 then the system call was
120
+
performed with the scv 0 instruction.
121
+
112
122
vsyscall
113
123
========
114
124
+26
-19
arch/powerpc/include/asm/ptrace.h
+26
-19
arch/powerpc/include/asm/ptrace.h
···
19
19
#ifndef _ASM_POWERPC_PTRACE_H
20
20
#define _ASM_POWERPC_PTRACE_H
21
21
22
+
#include <linux/err.h>
22
23
#include <uapi/asm/ptrace.h>
23
24
#include <asm/asm-const.h>
24
25
···
153
152
long do_syscall_trace_enter(struct pt_regs *regs);
154
153
void do_syscall_trace_leave(struct pt_regs *regs);
155
154
156
-
#define kernel_stack_pointer(regs) ((regs)->gpr[1])
157
-
static inline int is_syscall_success(struct pt_regs *regs)
158
-
{
159
-
return !(regs->ccr & 0x10000000);
160
-
}
161
-
162
-
static inline long regs_return_value(struct pt_regs *regs)
163
-
{
164
-
if (is_syscall_success(regs))
165
-
return regs->gpr[3];
166
-
else
167
-
return -regs->gpr[3];
168
-
}
169
-
170
-
static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
171
-
{
172
-
regs->gpr[3] = rc;
173
-
}
174
-
175
155
#ifdef __powerpc64__
176
156
#define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
177
157
#else
···
215
233
static __always_inline void set_trap_norestart(struct pt_regs *regs)
216
234
{
217
235
regs->trap |= 0x1;
236
+
}
237
+
238
+
#define kernel_stack_pointer(regs) ((regs)->gpr[1])
239
+
static inline int is_syscall_success(struct pt_regs *regs)
240
+
{
241
+
if (trap_is_scv(regs))
242
+
return !IS_ERR_VALUE((unsigned long)regs->gpr[3]);
243
+
else
244
+
return !(regs->ccr & 0x10000000);
245
+
}
246
+
247
+
static inline long regs_return_value(struct pt_regs *regs)
248
+
{
249
+
if (trap_is_scv(regs))
250
+
return regs->gpr[3];
251
+
252
+
if (is_syscall_success(regs))
253
+
return regs->gpr[3];
254
+
else
255
+
return -regs->gpr[3];
256
+
}
257
+
258
+
static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
259
+
{
260
+
regs->gpr[3] = rc;
218
261
}
219
262
220
263
#define arch_has_single_step() (1)
+26
-16
arch/powerpc/include/asm/syscall.h
+26
-16
arch/powerpc/include/asm/syscall.h
···
41
41
static inline long syscall_get_error(struct task_struct *task,
42
42
struct pt_regs *regs)
43
43
{
44
-
/*
45
-
* If the system call failed,
46
-
* regs->gpr[3] contains a positive ERRORCODE.
47
-
*/
48
-
return (regs->ccr & 0x10000000UL) ? -regs->gpr[3] : 0;
44
+
if (trap_is_scv(regs)) {
45
+
unsigned long error = regs->gpr[3];
46
+
47
+
return IS_ERR_VALUE(error) ? error : 0;
48
+
} else {
49
+
/*
50
+
* If the system call failed,
51
+
* regs->gpr[3] contains a positive ERRORCODE.
52
+
*/
53
+
return (regs->ccr & 0x10000000UL) ? -regs->gpr[3] : 0;
54
+
}
49
55
}
50
56
51
57
static inline long syscall_get_return_value(struct task_struct *task,
···
64
58
struct pt_regs *regs,
65
59
int error, long val)
66
60
{
67
-
/*
68
-
* In the general case it's not obvious that we must deal with CCR
69
-
* here, as the syscall exit path will also do that for us. However
70
-
* there are some places, eg. the signal code, which check ccr to
71
-
* decide if the value in r3 is actually an error.
72
-
*/
73
-
if (error) {
74
-
regs->ccr |= 0x10000000L;
75
-
regs->gpr[3] = error;
61
+
if (trap_is_scv(regs)) {
62
+
regs->gpr[3] = (long) error ?: val;
76
63
} else {
77
-
regs->ccr &= ~0x10000000L;
78
-
regs->gpr[3] = val;
64
+
/*
65
+
* In the general case it's not obvious that we must deal with
66
+
* CCR here, as the syscall exit path will also do that for us.
67
+
* However there are some places, eg. the signal code, which
68
+
* check ccr to decide if the value in r3 is actually an error.
69
+
*/
70
+
if (error) {
71
+
regs->ccr |= 0x10000000L;
72
+
regs->gpr[3] = error;
73
+
} else {
74
+
regs->ccr &= ~0x10000000L;
75
+
regs->gpr[3] = val;
76
+
}
79
77
}
80
78
}
81
79
+2
-2
arch/powerpc/kernel/setup_64.c
+2
-2
arch/powerpc/kernel/setup_64.c
···
369
369
apply_feature_fixups();
370
370
setup_feature_keys();
371
371
372
-
early_ioremap_setup();
373
-
374
372
/* Initialize the hash table or TLB handling */
375
373
early_init_mmu();
374
+
375
+
early_ioremap_setup();
376
376
377
377
/*
378
378
* After firmware and early platform setup code has set things up,
+18
-9
tools/testing/selftests/seccomp/seccomp_bpf.c
+18
-9
tools/testing/selftests/seccomp/seccomp_bpf.c
···
1753
1753
# define SYSCALL_RET_SET(_regs, _val) \
1754
1754
do { \
1755
1755
typeof(_val) _result = (_val); \
1756
-
/* \
1757
-
* A syscall error is signaled by CR0 SO bit \
1758
-
* and the code is stored as a positive value. \
1759
-
*/ \
1760
-
if (_result < 0) { \
1761
-
SYSCALL_RET(_regs) = -_result; \
1762
-
(_regs).ccr |= 0x10000000; \
1763
-
} else { \
1756
+
if ((_regs.trap & 0xfff0) == 0x3000) { \
1757
+
/* \
1758
+
* scv 0 system call uses -ve result \
1759
+
* for error, so no need to adjust. \
1760
+
*/ \
1764
1761
SYSCALL_RET(_regs) = _result; \
1765
-
(_regs).ccr &= ~0x10000000; \
1762
+
} else { \
1763
+
/* \
1764
+
* A syscall error is signaled by the \
1765
+
* CR0 SO bit and the code is stored as \
1766
+
* a positive value. \
1767
+
*/ \
1768
+
if (_result < 0) { \
1769
+
SYSCALL_RET(_regs) = -_result; \
1770
+
(_regs).ccr |= 0x10000000; \
1771
+
} else { \
1772
+
SYSCALL_RET(_regs) = _result; \
1773
+
(_regs).ccr &= ~0x10000000; \
1774
+
} \
1766
1775
} \
1767
1776
} while (0)
1768
1777
# define SYSCALL_RET_SET_ON_PTRACE_EXIT