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-rw-r--r--arch/mips/include/asm/syscall.h29
-rw-r--r--arch/mips/kernel/ptrace.c15
-rw-r--r--arch/mips/kernel/ptrace32.c7
3 files changed, 47 insertions, 4 deletions
diff --git a/arch/mips/include/asm/syscall.h b/arch/mips/include/asm/syscall.h
index 7c713025b23f..0170602a1e4e 100644
--- a/arch/mips/include/asm/syscall.h
+++ b/arch/mips/include/asm/syscall.h
@@ -26,12 +26,34 @@
#define __NR_syscall 4000
#endif
+static inline bool mips_syscall_is_indirect(struct task_struct *task,
+ struct pt_regs *regs)
+{
+ /* O32 ABI syscall() - Either 64-bit with O32 or 32-bit */
+ return (IS_ENABLED(CONFIG_32BIT) ||
+ test_tsk_thread_flag(task, TIF_32BIT_REGS)) &&
+ (regs->regs[2] == __NR_syscall);
+}
+
static inline long syscall_get_nr(struct task_struct *task,
struct pt_regs *regs)
{
return current_thread_info()->syscall;
}
+static inline void mips_syscall_update_nr(struct task_struct *task,
+ struct pt_regs *regs)
+{
+ /*
+ * v0 is the system call number, except for O32 ABI syscall(), where it
+ * ends up in a0.
+ */
+ if (mips_syscall_is_indirect(task, regs))
+ task_thread_info(task)->syscall = regs->regs[4];
+ else
+ task_thread_info(task)->syscall = regs->regs[2];
+}
+
static inline unsigned long mips_get_syscall_arg(unsigned long *arg,
struct task_struct *task, struct pt_regs *regs, unsigned int n)
{
@@ -98,10 +120,9 @@ static inline void syscall_get_arguments(struct task_struct *task,
unsigned long *args)
{
int ret;
- /* O32 ABI syscall() - Either 64-bit with O32 or 32-bit */
- if ((IS_ENABLED(CONFIG_32BIT) ||
- test_tsk_thread_flag(task, TIF_32BIT_REGS)) &&
- (regs->regs[2] == __NR_syscall))
+
+ /* O32 ABI syscall() */
+ if (mips_syscall_is_indirect(task, regs))
i++;
while (n--)
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index 011993e0cce2..efbd8df8b665 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -144,6 +144,9 @@ int ptrace_setregs(struct task_struct *child, struct user_pt_regs __user *data)
/* badvaddr, status, and cause may not be written. */
+ /* System call number may have been changed */
+ mips_syscall_update_nr(child, regs);
+
return 0;
}
@@ -345,6 +348,9 @@ static int gpr32_set(struct task_struct *target,
}
}
+ /* System call number may have been changed */
+ mips_syscall_update_nr(target, regs);
+
return 0;
}
@@ -405,6 +411,9 @@ static int gpr64_set(struct task_struct *target,
}
}
+ /* System call number may have been changed */
+ mips_syscall_update_nr(target, regs);
+
return 0;
}
@@ -770,6 +779,12 @@ long arch_ptrace(struct task_struct *child, long request,
switch (addr) {
case 0 ... 31:
regs->regs[addr] = data;
+ /* System call number may have been changed */
+ if (addr == 2)
+ mips_syscall_update_nr(child, regs);
+ else if (addr == 4 &&
+ mips_syscall_is_indirect(child, regs))
+ mips_syscall_update_nr(child, regs);
break;
case FPR_BASE ... FPR_BASE + 31: {
union fpureg *fregs = get_fpu_regs(child);
diff --git a/arch/mips/kernel/ptrace32.c b/arch/mips/kernel/ptrace32.c
index 40e212d6b26b..2b9260f92ccd 100644
--- a/arch/mips/kernel/ptrace32.c
+++ b/arch/mips/kernel/ptrace32.c
@@ -33,6 +33,7 @@
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/reg.h>
+#include <asm/syscall.h>
#include <linux/uaccess.h>
#include <asm/bootinfo.h>
@@ -195,6 +196,12 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
switch (addr) {
case 0 ... 31:
regs->regs[addr] = data;
+ /* System call number may have been changed */
+ if (addr == 2)
+ mips_syscall_update_nr(child, regs);
+ else if (addr == 4 &&
+ mips_syscall_is_indirect(child, regs))
+ mips_syscall_update_nr(child, regs);
break;
case FPR_BASE ... FPR_BASE + 31: {
union fpureg *fregs = get_fpu_regs(child);