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-rw-r--r--arch/alpha/kernel/entry.S111
-rw-r--r--arch/alpha/kernel/pci.c1
-rw-r--r--arch/alpha/kernel/ptrace.c83
3 files changed, 174 insertions, 21 deletions
diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S
index f4d41b4538c2..fcfd06529b12 100644
--- a/arch/alpha/kernel/entry.S
+++ b/arch/alpha/kernel/entry.S
@@ -10,6 +10,7 @@
#include <asm/pal.h>
#include <asm/errno.h>
#include <asm/unistd.h>
+#include <linux/errno.h>
.text
.set noat
@@ -36,6 +37,64 @@
.endm
/*
+ * SYSCALL_SKIP_RETURN_RESTART_GATE
+ *
+ * Used when syscall dispatch is skipped (seccomp/ptrace injected nr=-1).
+ * - Ensure we never return r0==-1 with a3==0 (success); convert to ENOSYS.
+ * - Gate whether syscall restart is allowed by preserving restart context
+ * only for ERESTART* returns. Result:
+ * $26 = 0 => restart allowed
+ * $26 = 1 => restart NOT allowed
+ * $18 = preserved syscall nr (regs->r2) if restart allowed, else 0
+ */
+.macro SYSCALL_SKIP_RETURN_RESTART_GATE
+ /* Fix up invalid "-1 success" return state. */
+ ldq $19, 72($sp) /* a3 */
+ bne $19, 1f /* already error => skip fixup */
+
+ ldq $20, 0($sp) /* r0 */
+ lda $21, -1($31)
+ cmpeq $20, $21, $22
+ beq $22, 1f /* r0 != -1 => skip fixup */
+
+
+ lda $20, ENOSYS($31)
+ stq $20, 0($sp) /* r0 = ENOSYS */
+ lda $19, 1($31)
+ stq $19, 72($sp) /* a3 = 1 */
+1:
+ /* Restart gating: success is never restartable here. */
+ ldq $19, 72($sp) /* a3 */
+ beq $19, 3f /* success => not restartable */
+
+ ldq $20, 0($sp) /* r0 (positive errno if a3==1) */
+ lda $21, ERESTARTSYS($31)
+ cmpeq $20, $21, $22
+ bne $22, 2f
+ lda $21, ERESTARTNOINTR($31)
+ cmpeq $20, $21, $22
+ bne $22, 2f
+ lda $21, ERESTARTNOHAND($31)
+ cmpeq $20, $21, $22
+ bne $22, 2f
+ lda $21, ERESTART_RESTARTBLOCK($31)
+ cmpeq $20, $21, $22
+ bne $22, 2f
+
+3: /* Not a restart code (or success) => restart NOT allowed. */
+ addq $31, 1, $26 /* $26=1 => restart NOT allowed */
+ mov 0, $18
+ br 4f
+
+2: /* Restart allowed. */
+ ldq $18, 16($sp) /* preserved syscall nr (regs->r2) */
+ mov $31, $26 /* $26=0 => restart allowed */
+ br 4f
+4:
+.endm
+
+
+/*
* This defines the normal kernel pt-regs layout.
*
* regs 9-15 preserved by C code
@@ -425,7 +484,7 @@ CFI_START_OSF_FRAME entDbg
mov $sp, $16
jsr $31, do_entDbg
CFI_END_OSF_FRAME entDbg
-
+
/*
* The system call entry point is special. Most importantly, it looks
* like a function call to userspace as far as clobbered registers. We
@@ -435,6 +494,17 @@ CFI_END_OSF_FRAME entDbg
* So much for theory. We don't take advantage of this yet.
*
* Note that a0-a2 are not saved by PALcode as with the other entry points.
+ *
+ * Alpha syscall ABI uses:
+ * - r0 for return value
+ * - r19 ("a3") as error indicator (0=success, 1=error; r0 holds errno)
+ *
+ * For seccomp/ptrace/generic syscall helpers we track the syscall
+ * number separately:
+ * - regs->r1: current (mutable) syscall number (may be changed or set to -1)
+ * - regs->r2: original syscall number for restart/rollback
+ *
+ * On entry PAL provides the syscall number in r0; copy it into r1/r2.
*/
.align 4
@@ -447,6 +517,10 @@ CFI_END_OSF_FRAME entDbg
.cfi_rel_offset $gp, 16
entSys:
SAVE_ALL
+ ldq $1, 0($sp) /* syscall nr from saved r0 */
+ stq $1, 8($sp) /* regs->r1 = shadow syscall nr */
+ stq $1, 16($sp) /* regs->r2 = restart syscall nr */
+
lda $8, 0x3fff
bic $sp, $8, $8
lda $4, NR_syscalls($31)
@@ -462,15 +536,19 @@ entSys:
.cfi_rel_offset $17, SP_OFF+32
.cfi_rel_offset $18, SP_OFF+40
#ifdef CONFIG_AUDITSYSCALL
- lda $6, _TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT
+ lda $6, _TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP
and $3, $6, $3
bne $3, strace
#else
- blbs $3, strace /* check for SYSCALL_TRACE in disguise */
+ lda $6, _TIF_SYSCALL_TRACE | _TIF_SECCOMP
+ and $3, $6, $3
+ bne $3, strace
#endif
beq $4, 1f
ldq $27, 0($5)
-1: jsr $26, ($27), sys_ni_syscall
+1: ldq $0, 8($sp) /* syscall nr shadow (regs->r1) */
+
+ jsr $26, ($27), sys_ni_syscall
ldgp $gp, 0($26)
blt $0, $syscall_error /* the call failed */
$ret_success:
@@ -509,15 +587,8 @@ ret_to_kernel:
.align 3
$syscall_error:
- /*
- * Some system calls (e.g., ptrace) can return arbitrary
- * values which might normally be mistaken as error numbers.
- * Those functions must zero $0 (v0) directly in the stack
- * frame to indicate that a negative return value wasn't an
- * error number..
- */
- ldq $18, 0($sp) /* old syscall nr (zero if success) */
- beq $18, $ret_success
+ /* Restart syscall nr comes from saved r2 (preserved even if r0 overwritten). */
+ ldq $18, 16($sp) /* old syscall nr for restart */
ldq $19, 72($sp) /* .. and this a3 */
subq $31, $0, $0 /* with error in v0 */
@@ -581,6 +652,8 @@ strace:
jsr $26, syscall_trace_enter /* returns the syscall number */
UNDO_SWITCH_STACK
+ stq $0, 8($sp) /* regs->r1 = shadow syscall nr */
+
/* get the arguments back.. */
ldq $16, SP_OFF+24($sp)
ldq $17, SP_OFF+32($sp)
@@ -589,6 +662,11 @@ strace:
ldq $20, 80($sp)
ldq $21, 88($sp)
+ /* nr == -1: internal skip-dispatch or userspace syscall(-1)? */
+ lda $6, -1($31)
+ cmpeq $0, $6, $6
+ bne $6, $strace_skip_call /* nr == -1 => dispatch */
+
/* get the system call pointer.. */
lda $1, NR_syscalls($31)
lda $2, sys_call_table
@@ -607,6 +685,8 @@ $strace_success:
stq $31, 72($sp) /* a3=0 => no error */
stq $0, 0($sp) /* save return value */
+$strace_skip_call:
+ SYSCALL_SKIP_RETURN_RESTART_GATE
DO_SWITCH_STACK
jsr $26, syscall_trace_leave
UNDO_SWITCH_STACK
@@ -614,8 +694,7 @@ $strace_success:
.align 3
$strace_error:
- ldq $18, 0($sp) /* old syscall nr (zero if success) */
- beq $18, $strace_success
+ ldq $18, 16($sp) /* restart syscall nr */
ldq $19, 72($sp) /* .. and this a3 */
subq $31, $0, $0 /* with error in v0 */
@@ -634,7 +713,7 @@ $strace_error:
mov $31, $26 /* tell "ret_from_sys_call" we can restart */
br ret_from_sys_call
CFI_END_OSF_FRAME entSys
-
+
/*
* Save and restore the switch stack -- aka the balance of the user context.
*/
diff --git a/arch/alpha/kernel/pci.c b/arch/alpha/kernel/pci.c
index 51a8a4c4572a..11df411b1d18 100644
--- a/arch/alpha/kernel/pci.c
+++ b/arch/alpha/kernel/pci.c
@@ -125,6 +125,7 @@ DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, pcibios_fixup_final);
resource_size_t
pcibios_align_resource(void *data, const struct resource *res,
+ const struct resource *empty_res,
resource_size_t size, resource_size_t align)
{
struct pci_dev *dev = data;
diff --git a/arch/alpha/kernel/ptrace.c b/arch/alpha/kernel/ptrace.c
index fde4c68e7a0b..0687760ea466 100644
--- a/arch/alpha/kernel/ptrace.c
+++ b/arch/alpha/kernel/ptrace.c
@@ -16,11 +16,14 @@
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/audit.h>
+#include <linux/seccomp.h>
+#include <asm/syscall.h>
#include <linux/uaccess.h>
#include <asm/fpu.h>
#include "proto.h"
+#include <linux/uio.h>
#define DEBUG DBG_MEM
#undef DEBUG
@@ -312,6 +315,54 @@ long arch_ptrace(struct task_struct *child, long request,
DBG(DBG_MEM, ("poke $%lu<-%#lx\n", addr, data));
ret = put_reg(child, addr, data);
break;
+ case PTRACE_GETREGSET:
+ case PTRACE_SETREGSET: {
+ struct iovec __user *uiov = (struct iovec __user *)data;
+ struct iovec iov;
+ struct pt_regs *regs;
+ size_t len;
+
+ /* Only support NT_PRSTATUS (general registers) for now. */
+ if (addr != NT_PRSTATUS) {
+ ret = -EIO;
+ break;
+ }
+
+ if (copy_from_user(&iov, uiov, sizeof(iov))) {
+ ret = -EFAULT;
+ break;
+ }
+
+ regs = task_pt_regs(child);
+ len = min_t(size_t, iov.iov_len, sizeof(*regs));
+
+ if (request == PTRACE_GETREGSET) {
+ if (copy_to_user(iov.iov_base, regs, len)) {
+ ret = -EFAULT;
+ break;
+ }
+ } else {
+ /*
+ * Allow writing back regs. This is needed by the TRACE_syscall
+ * tests (they change PC/syscall nr/retval).
+ */
+ if (copy_from_user(regs, iov.iov_base, len)) {
+ ret = -EFAULT;
+ break;
+ }
+ }
+
+ /* Per API, update iov_len with amount transferred. */
+ iov.iov_len = len;
+ if (copy_to_user(uiov, &iov, sizeof(iov))) {
+ ret = -EFAULT;
+ break;
+ }
+
+ ret = 0;
+ break;
+ }
+
default:
ret = ptrace_request(child, request, addr, data);
break;
@@ -321,15 +372,37 @@ long arch_ptrace(struct task_struct *child, long request,
asmlinkage unsigned long syscall_trace_enter(void)
{
- unsigned long ret = 0;
struct pt_regs *regs = current_pt_regs();
+
if (test_thread_flag(TIF_SYSCALL_TRACE) &&
- ptrace_report_syscall_entry(current_pt_regs()))
- ret = -1UL;
- audit_syscall_entry(regs->r0, regs->r16, regs->r17, regs->r18, regs->r19);
- return ret ?: current_pt_regs()->r0;
+ ptrace_report_syscall_entry(regs)) {
+ syscall_set_nr(current, regs, -1);
+ if (regs->r19 == 0 && regs->r0 == (unsigned long)-1)
+ syscall_set_return_value(current, regs, -ENOSYS, 0);
+ return -1UL;
+ }
+
+ /*
+ * Do the secure computing after ptrace; failures should be fast.
+ * If this fails, seccomp may already have set up the return value
+ * (e.g. SECCOMP_RET_ERRNO / TRACE).
+ */
+ if (secure_computing() == -1) {
+ if (regs->r19 == 0 && regs->r0 == (unsigned long)-1)
+ syscall_set_return_value(current, regs, -ENOSYS, 0);
+ syscall_set_nr(current, regs, -1);
+ return -1UL;
+ }
+
+#ifdef CONFIG_AUDITSYSCALL
+ audit_syscall_entry(syscall_get_nr(current, regs),
+ regs->r16, regs->r17, regs->r18, regs->r19);
+#endif
+ return syscall_get_nr(current, regs);
}
+
+
asmlinkage void
syscall_trace_leave(void)
{
generated by cgit v1.2.3 (git 2.0.4) at 2026-04-30 04:37:05 +0000