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authorLinus Torvalds <torvalds@linux-foundation.org>2021-05-23 06:07:33 -1000
committerLinus Torvalds <torvalds@linux-foundation.org>2021-05-23 06:07:33 -1000
commit28ceac6959e1db015729c52ec74e0a4ff496c2b8 (patch)
tree1fda20fa530a3bd3f2c96113d644d68921145738
parent4d7620341eda38573a73ab63c33423534fa38eb9 (diff)
parentd72500f992849d31ebae8f821a023660ddd0dcc2 (diff)
downloadlinux-28ceac6959e1db015729c52ec74e0a4ff496c2b8.tar.bz2
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
-rw-r--r--Documentation/powerpc/syscall64-abi.rst10
-rw-r--r--arch/powerpc/include/asm/ptrace.h45
-rw-r--r--arch/powerpc/include/asm/syscall.h42
-rw-r--r--arch/powerpc/kernel/setup_64.c4
-rw-r--r--tools/testing/selftests/seccomp/seccomp_bpf.c27
5 files changed, 82 insertions, 46 deletions
diff --git a/Documentation/powerpc/syscall64-abi.rst b/Documentation/powerpc/syscall64-abi.rst
index dabee3729e5a..56490c4c0c07 100644
--- a/Documentation/powerpc/syscall64-abi.rst
+++ b/Documentation/powerpc/syscall64-abi.rst
@@ -109,6 +109,16 @@ auxiliary vector.
scv 0 syscalls will always behave as PPC_FEATURE2_HTM_NOSC.
+ptrace
+------
+When ptracing system calls (PTRACE_SYSCALL), the pt_regs.trap value contains
+the system call type that can be used to distinguish between sc and scv 0
+system calls, and the different register conventions can be accounted for.
+
+If the value of (pt_regs.trap & 0xfff0) is 0xc00 then the system call was
+performed with the sc instruction, if it is 0x3000 then the system call was
+performed with the scv 0 instruction.
+
vsyscall
========
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 9c9ab2746168..b476a685f066 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -19,6 +19,7 @@
#ifndef _ASM_POWERPC_PTRACE_H
#define _ASM_POWERPC_PTRACE_H
+#include <linux/err.h>
#include <uapi/asm/ptrace.h>
#include <asm/asm-const.h>
@@ -152,25 +153,6 @@ extern unsigned long profile_pc(struct pt_regs *regs);
long do_syscall_trace_enter(struct pt_regs *regs);
void do_syscall_trace_leave(struct pt_regs *regs);
-#define kernel_stack_pointer(regs) ((regs)->gpr[1])
-static inline int is_syscall_success(struct pt_regs *regs)
-{
- return !(regs->ccr & 0x10000000);
-}
-
-static inline long regs_return_value(struct pt_regs *regs)
-{
- if (is_syscall_success(regs))
- return regs->gpr[3];
- else
- return -regs->gpr[3];
-}
-
-static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
-{
- regs->gpr[3] = rc;
-}
-
#ifdef __powerpc64__
#define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
#else
@@ -235,6 +217,31 @@ static __always_inline void set_trap_norestart(struct pt_regs *regs)
regs->trap |= 0x1;
}
+#define kernel_stack_pointer(regs) ((regs)->gpr[1])
+static inline int is_syscall_success(struct pt_regs *regs)
+{
+ if (trap_is_scv(regs))
+ return !IS_ERR_VALUE((unsigned long)regs->gpr[3]);
+ else
+ return !(regs->ccr & 0x10000000);
+}
+
+static inline long regs_return_value(struct pt_regs *regs)
+{
+ if (trap_is_scv(regs))
+ return regs->gpr[3];
+
+ if (is_syscall_success(regs))
+ return regs->gpr[3];
+ else
+ return -regs->gpr[3];
+}
+
+static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
+{
+ regs->gpr[3] = rc;
+}
+
#define arch_has_single_step() (1)
#define arch_has_block_step() (true)
#define ARCH_HAS_USER_SINGLE_STEP_REPORT
diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h
index fd1b518eed17..ba0f88f3a30d 100644
--- a/arch/powerpc/include/asm/syscall.h
+++ b/arch/powerpc/include/asm/syscall.h
@@ -41,11 +41,17 @@ static inline void syscall_rollback(struct task_struct *task,
static inline long syscall_get_error(struct task_struct *task,
struct pt_regs *regs)
{
- /*
- * If the system call failed,
- * regs->gpr[3] contains a positive ERRORCODE.
- */
- return (regs->ccr & 0x10000000UL) ? -regs->gpr[3] : 0;
+ if (trap_is_scv(regs)) {
+ unsigned long error = regs->gpr[3];
+
+ return IS_ERR_VALUE(error) ? error : 0;
+ } else {
+ /*
+ * If the system call failed,
+ * regs->gpr[3] contains a positive ERRORCODE.
+ */
+ return (regs->ccr & 0x10000000UL) ? -regs->gpr[3] : 0;
+ }
}
static inline long syscall_get_return_value(struct task_struct *task,
@@ -58,18 +64,22 @@ static inline void syscall_set_return_value(struct task_struct *task,
struct pt_regs *regs,
int error, long val)
{
- /*
- * In the general case it's not obvious that we must deal with CCR
- * here, as the syscall exit path will also do that for us. However
- * there are some places, eg. the signal code, which check ccr to
- * decide if the value in r3 is actually an error.
- */
- if (error) {
- regs->ccr |= 0x10000000L;
- regs->gpr[3] = error;
+ if (trap_is_scv(regs)) {
+ regs->gpr[3] = (long) error ?: val;
} else {
- regs->ccr &= ~0x10000000L;
- regs->gpr[3] = val;
+ /*
+ * In the general case it's not obvious that we must deal with
+ * CCR here, as the syscall exit path will also do that for us.
+ * However there are some places, eg. the signal code, which
+ * check ccr to decide if the value in r3 is actually an error.
+ */
+ if (error) {
+ regs->ccr |= 0x10000000L;
+ regs->gpr[3] = error;
+ } else {
+ regs->ccr &= ~0x10000000L;
+ regs->gpr[3] = val;
+ }
}
}
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index b779d25761cf..e42b85e4f1aa 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -369,11 +369,11 @@ void __init early_setup(unsigned long dt_ptr)
apply_feature_fixups();
setup_feature_keys();
- early_ioremap_setup();
-
/* Initialize the hash table or TLB handling */
early_init_mmu();
+ early_ioremap_setup();
+
/*
* After firmware and early platform setup code has set things up,
* we note the SPR values for configurable control/performance
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index 98c3b647f54d..e3d5c77a8612 100644
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -1753,16 +1753,25 @@ TEST_F(TRACE_poke, getpid_runs_normally)
# define SYSCALL_RET_SET(_regs, _val) \
do { \
typeof(_val) _result = (_val); \
- /* \
- * A syscall error is signaled by CR0 SO bit \
- * and the code is stored as a positive value. \
- */ \
- if (_result < 0) { \
- SYSCALL_RET(_regs) = -_result; \
- (_regs).ccr |= 0x10000000; \
- } else { \
+ if ((_regs.trap & 0xfff0) == 0x3000) { \
+ /* \
+ * scv 0 system call uses -ve result \
+ * for error, so no need to adjust. \
+ */ \
SYSCALL_RET(_regs) = _result; \
- (_regs).ccr &= ~0x10000000; \
+ } else { \
+ /* \
+ * A syscall error is signaled by the \
+ * CR0 SO bit and the code is stored as \
+ * a positive value. \
+ */ \
+ if (_result < 0) { \
+ SYSCALL_RET(_regs) = -_result; \
+ (_regs).ccr |= 0x10000000; \
+ } else { \
+ SYSCALL_RET(_regs) = _result; \
+ (_regs).ccr &= ~0x10000000; \
+ } \
} \
} while (0)
# define SYSCALL_RET_SET_ON_PTRACE_EXIT