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arm64: ptrace: Fix overwriting 1st argument with return value

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Since arm64 shares the return value with the area of
the first argument, rewriting the return value before
the system call execution completes destroys the first argument.

Change-Id: I959944879254d8dd3a29489a65d8f274d45338e6
Fujitsu: POSTK_DEBUG_ARCH_DEP_110
This commit is contained in:
Shiratori, Takehiro
2019-03-05 12:22:18 +09:00
committed by Masamichi Takagi
parent ac18a24a27
commit ea7f517e3d
4 changed files with 35 additions and 8 deletions
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8
arch/arm64/kernel/syscall.c
View File

@ -2735,4 +2735,12 @@ void calculate_time_from_tsc(struct timespec *ts)
++ts->tv_sec;
}
}
extern void ptrace_syscall_event(struct thread *thread);
long arch_ptrace_syscall_event(struct thread *thread,
ihk_mc_user_context_t *ctx, long setret)
{
ptrace_syscall_event(thread);
return setret;
}
/*** End of File ***/

9
arch/x86_64/kernel/syscall.c
View File

@ -2858,4 +2858,13 @@ void calculate_time_from_tsc(struct timespec *ts)
++ts->tv_sec;
}
}
extern void ptrace_syscall_event(struct thread *thread);
long arch_ptrace_syscall_event(struct thread *thread,
ihk_mc_user_context_t *ctx, long setret)
{
ihk_mc_syscall_ret(ctx) = setret;
ptrace_syscall_event(thread);
return ihk_mc_syscall_ret(ctx);
}
/*** End of File ***/

4
kernel/include/syscall.h
View File

@ -586,6 +586,10 @@ typedef struct uti_attr {
uint64_t flags; /* Representing location and behavior hints by bitmap */
} uti_attr_t;
struct thread;
long arch_ptrace_syscall_event(struct thread *thread,
ihk_mc_user_context_t *ctx, long setret);
struct uti_ctx {
union {
char ctx[4096];

22
kernel/syscall.c
View File

@ -2273,7 +2273,7 @@ static int ptrace_report_exec(struct thread *thread)
return 0;
}
static void ptrace_syscall_event(struct thread *thread)
void ptrace_syscall_event(struct thread *thread)
{
int ptrace = thread->ptrace;
@ -2551,8 +2551,7 @@ SYSCALL_DECLARE(execve)
}
if (thread->ptrace) {
ihk_mc_syscall_ret(ctx) = 0;
ptrace_syscall_event(thread);
arch_ptrace_syscall_event(thread, ctx, 0);
}
/* Unmap all memory areas of the process, userspace will be gone */
@ -9619,6 +9618,9 @@ long syscall(int num, ihk_mc_user_context_t *ctx)
if(cpu_local_var(current)->proc->status == PS_EXITED &&
(num != __NR_exit && num != __NR_exit_group)){
/* x86_64: Setting -EINVAL to rax is done in the
* following return.
*/
save_syscall_return_value(num, -EINVAL);
check_signal(-EINVAL, NULL, -1);
set_cputime(CPUTIME_MODE_K2U);
@ -9628,8 +9630,8 @@ long syscall(int num, ihk_mc_user_context_t *ctx)
cpu_enable_interrupt();
if (cpu_local_var(current)->ptrace) {
ihk_mc_syscall_ret(ctx) = -ENOSYS;
ptrace_syscall_event(cpu_local_var(current));
arch_ptrace_syscall_event(cpu_local_var(current),
ctx, -ENOSYS);
num = ihk_mc_syscall_number(ctx);
}
@ -9675,11 +9677,15 @@ long syscall(int num, ihk_mc_user_context_t *ctx)
}
if (cpu_local_var(current)->ptrace) {
ihk_mc_syscall_ret(ctx) = l;
ptrace_syscall_event(cpu_local_var(current));
l = ihk_mc_syscall_ret(ctx);
/* arm64: The return value modified by the tracer is
* stored to x0 in the following check_signal().
*/
l = arch_ptrace_syscall_event(cpu_local_var(current), ctx, l);
}
/* x86_64: Setting l to rax is done in the
* following return.
*/
save_syscall_return_value(num, l);
#ifdef PROFILE_ENABLE