Re: [Qemu-devel] [PATCH] linux-user sigaltstack() syscall
On Mon, 2007-09-24 at 23:04 -0600, Thayne Harbaugh wrote:
This patch adds the sigaltstack() syscall for linux-user.
The previous patch relied on the EFAULT patch, this newer version does
not. It also fixes a few places that used tswap32() that should use
__put_user().
Index: qemu/linux-user/signal.c
===
--- qemu.orig/linux-user/signal.c 2007-09-25 05:46:34.0 -0600
+++ qemu/linux-user/signal.c 2007-09-25 06:35:23.0 -0600
@@ -26,6 +26,7 @@
#include errno.h
#include sys/ucontext.h
+#include target_signal.h
#include qemu.h
//#define DEBUG_SIGNAL
@@ -45,6 +46,12 @@
first signal, we put it here */
};
+struct target_sigaltstack target_sigaltstack_used = {
+.ss_sp = 0,
+.ss_size = 0,
+.ss_flags = TARGET_SS_DISABLE,
+};
+
static struct emulated_sigaction sigact_table[TARGET_NSIG];
static struct sigqueue sigqueue_table[MAX_SIGQUEUE_SIZE]; /* siginfo queue */
static struct sigqueue *first_free; /* first free siginfo queue entry */
@@ -92,6 +99,18 @@
};
static uint8_t target_to_host_signal_table[65];
+static inline int on_sig_stack(unsigned long sp)
+{
+return (sp - target_sigaltstack_used.ss_sp
+ target_sigaltstack_used.ss_size);
+}
+
+static inline int sas_ss_flags(unsigned long sp)
+{
+return (target_sigaltstack_used.ss_size == 0 ? SS_DISABLE
+: on_sig_stack(sp) ? SS_ONSTACK : 0);
+}
+
static inline int host_to_target_signal(int sig)
{
return host_to_target_signal_table[sig];
@@ -419,6 +438,67 @@
}
}
+int do_sigaltstack(const struct target_sigaltstack *uss,
+ struct target_sigaltstack *uoss,
+ target_ulong sp)
+{
+int ret;
+struct target_sigaltstack oss;
+
+/* XXX: test errors */
+if(uoss)
+{
+__put_user(target_sigaltstack_used.ss_sp, oss.ss_sp);
+__put_user(target_sigaltstack_used.ss_size, oss.ss_size);
+__put_user(sas_ss_flags(sp), oss.ss_flags);
+}
+
+if(uss)
+{
+ struct target_sigaltstack ss;
+
+ ret = -EFAULT;
+ if (!access_ok(VERIFY_READ, uss, sizeof(*uss))
+ || __get_user(ss.ss_sp, uss-ss_sp)
+ || __get_user(ss.ss_size, uss-ss_size)
+ || __get_user(ss.ss_flags, uss-ss_flags))
+goto out;
+
+ ret = -EPERM;
+ if (on_sig_stack(sp))
+goto out;
+
+ ret = -EINVAL;
+ if (ss.ss_flags != TARGET_SS_DISABLE
+ ss.ss_flags != TARGET_SS_ONSTACK
+ ss.ss_flags != 0)
+goto out;
+
+ if (ss.ss_flags == TARGET_SS_DISABLE) {
+ss.ss_size = 0;
+ss.ss_sp = 0;
+ } else {
+ret = -ENOMEM;
+if (ss.ss_size MINSIGSTKSZ)
+goto out;
+ }
+
+target_sigaltstack_used.ss_sp = ss.ss_sp;
+target_sigaltstack_used.ss_size = ss.ss_size;
+}
+
+if (uoss) {
+ret = -EFAULT;
+if (!access_ok(VERIFY_WRITE, uoss, sizeof(oss)))
+goto out;
+memcpy(uoss, oss, sizeof(oss));
+}
+
+ret = 0;
+out:
+return ret;
+}
+
int do_sigaction(int sig, const struct target_sigaction *act,
struct target_sigaction *oact)
{
@@ -551,12 +631,6 @@
target_ulong cr2;
};
-typedef struct target_sigaltstack {
- target_ulong ss_sp;
- int ss_flags;
- target_ulong ss_size;
-} target_stack_t;
-
struct target_ucontext {
target_ulong tuc_flags;
target_ulong tuc_link;
@@ -640,16 +714,14 @@
/* Default to using normal stack */
esp = env-regs[R_ESP];
-#if 0
/* This is the X/Open sanctioned signal stack switching. */
- if (ka-sa.sa_flags SA_ONSTACK) {
- if (sas_ss_flags(esp) == 0)
- esp = current-sas_ss_sp + current-sas_ss_size;
- }
+if (ka-sa.sa_flags TARGET_SA_ONSTACK) {
+if (sas_ss_flags(esp) == 0)
+esp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
+}
/* This is the legacy signal stack switching. */
else
-#endif
if ((env-segs[R_SS].selector 0x) != __USER_DS
!(ka-sa.sa_flags TARGET_SA_RESTORER)
ka-sa.sa_restorer) {
@@ -750,11 +822,11 @@
/* Create the ucontext. */
err |= __put_user(0, frame-uc.tuc_flags);
err |= __put_user(0, frame-uc.tuc_link);
- err |= __put_user(/*current-sas_ss_sp*/ 0,
+ err |= __put_user(target_sigaltstack_used.ss_sp,
frame-uc.tuc_stack.ss_sp);
- err |= __put_user(/* sas_ss_flags(regs-esp) */ 0,
+ err |= __put_user(sas_ss_flags(get_sp_from_cpustate(env)),
frame-uc.tuc_stack.ss_flags);
- err |= __put_user(/* current-sas_ss_size */ 0,
+ err |= __put_user(target_sigaltstack_used.ss_size,
frame-uc.tuc_stack.ss_size);
err |= setup_sigcontext(frame-uc.tuc_mcontext, frame-fpstate,
env, set-sig[0]);
@@ -880,7 +952,6 @@
{
struct rt_sigframe *frame = (struct rt_sigframe *)g2h(env-regs[R_ESP] - 4);
sigset_t set;
-// stack_t st;
int eax;
#if 0
@@ -893,13 +964,9 @@
if
[Qemu-devel] [PATCH] linux-user sigaltstack() syscall
This patch adds the sigaltstack() syscall for linux-user.
Index: qemu/linux-user/signal.c
===
--- qemu.orig/linux-user/signal.c 2007-09-24 22:45:48.0 -0600
+++ qemu/linux-user/signal.c 2007-09-24 22:56:18.0 -0600
@@ -26,6 +26,7 @@
#include errno.h
#include sys/ucontext.h
+#include target_signal.h
#include qemu.h
/*
@@ -51,6 +52,12 @@
first signal, we put it here */
};
+struct target_sigaltstack target_sigaltstack_used = {
+.ss_sp = 0,
+.ss_size = 0,
+.ss_flags = TARGET_SS_DISABLE,
+};
+
static struct emulated_sigaction sigact_table[TARGET_NSIG];
static struct sigqueue sigqueue_table[MAX_SIGQUEUE_SIZE]; /* siginfo queue */
static struct sigqueue *first_free; /* first free siginfo queue entry */
@@ -98,6 +105,18 @@
};
static uint8_t target_to_host_signal_table[65];
+static inline int on_sig_stack(unsigned long sp)
+{
+return (sp - target_sigaltstack_used.ss_sp
+ target_sigaltstack_used.ss_size);
+}
+
+static inline int sas_ss_flags(unsigned long sp)
+{
+return (target_sigaltstack_used.ss_size == 0 ? SS_DISABLE
+: on_sig_stack(sp) ? SS_ONSTACK : 0);
+}
+
static inline int host_to_target_signal(int sig)
{
return host_to_target_signal_table[sig];
@@ -420,6 +439,66 @@
}
}
+int do_sigaltstack(const struct target_sigaltstack *uss,
+ struct target_sigaltstack *uoss,
+ target_ulong sp)
+{
+int ret;
+struct target_sigaltstack oss;
+
+/* XXX: test errors */
+if(uoss)
+{
+oss.ss_sp = tswap32(target_sigaltstack_used.ss_sp);
+oss.ss_size = tswap32(target_sigaltstack_used.ss_size);
+oss.ss_flags = tswap32(sas_ss_flags(sp));
+}
+
+if(uss)
+{
+ struct target_sigaltstack ss;
+
+ ret = -EFAULT;
+ if (!access_ok(VERIFY_READ, uss, sizeof(*uss))
+ || __get_user(ss.ss_sp, uss-ss_sp)
+ || __get_user(ss.ss_size, uss-ss_size)
+ || __get_user(ss.ss_flags, uss-ss_flags))
+goto out;
+
+ ret = -EPERM;
+ if (on_sig_stack(sp))
+goto out;
+
+ ret = -EINVAL;
+ if (ss.ss_flags != TARGET_SS_DISABLE
+ ss.ss_flags != TARGET_SS_ONSTACK
+ ss.ss_flags != 0)
+goto out;
+
+ if (ss.ss_flags == TARGET_SS_DISABLE) {
+ss.ss_size = 0;
+ss.ss_sp = 0;
+ } else {
+ret = -ENOMEM;
+if (ss.ss_size MINSIGSTKSZ)
+goto out;
+ }
+
+target_sigaltstack_used.ss_sp = ss.ss_sp;
+target_sigaltstack_used.ss_size = ss.ss_size;
+}
+
+if (uoss) {
+ret = -EFAULT;
+if (copy_to_user(uoss, oss, sizeof(oss)))
+goto out;
+}
+
+ret = 0;
+out:
+return ret;
+}
+
int do_sigaction(int sig, const struct target_sigaction *act,
struct target_sigaction *oact)
{
@@ -550,12 +629,6 @@
target_ulong cr2;
};
-typedef struct target_sigaltstack {
- target_ulong ss_sp;
- int ss_flags;
- target_ulong ss_size;
-} target_stack_t;
-
struct target_ucontext {
target_ulong tuc_flags;
target_ulong tuc_link;
@@ -639,16 +712,14 @@
/* Default to using normal stack */
esp = env-regs[R_ESP];
-#if 0
/* This is the X/Open sanctioned signal stack switching. */
- if (ka-sa.sa_flags SA_ONSTACK) {
- if (sas_ss_flags(esp) == 0)
- esp = current-sas_ss_sp + current-sas_ss_size;
- }
+if (ka-sa.sa_flags TARGET_SA_ONSTACK) {
+if (sas_ss_flags(esp) == 0)
+esp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
+}
/* This is the legacy signal stack switching. */
else
-#endif
if ((env-segs[R_SS].selector 0x) != __USER_DS
!(ka-sa.sa_flags TARGET_SA_RESTORER)
ka-sa.sa_restorer) {
@@ -749,11 +820,11 @@
/* Create the ucontext. */
err |= __put_user(0, frame-uc.tuc_flags);
err |= __put_user(0, frame-uc.tuc_link);
- err |= __put_user(/*current-sas_ss_sp*/ 0,
+ err |= __put_user(target_sigaltstack_used.ss_sp,
frame-uc.tuc_stack.ss_sp);
- err |= __put_user(/* sas_ss_flags(regs-esp) */ 0,
+ err |= __put_user(sas_ss_flags(get_sp_from_cpustate(env)),
frame-uc.tuc_stack.ss_flags);
- err |= __put_user(/* current-sas_ss_size */ 0,
+ err |= __put_user(target_sigaltstack_used.ss_size,
frame-uc.tuc_stack.ss_size);
err |= setup_sigcontext(frame-uc.tuc_mcontext, frame-fpstate,
env, set-sig[0]);
@@ -877,7 +948,6 @@
{
struct rt_sigframe *frame = (struct rt_sigframe *)g2h(env-regs[R_ESP] - 4);
sigset_t set;
-// stack_t st;
int eax;
#if 0
@@ -890,13 +960,9 @@
if (restore_sigcontext(env, frame-uc.tuc_mcontext, eax))
goto badframe;
-#if 0
- if (__copy_from_user(st, frame-uc.tuc_stack, sizeof(st)))
+ if (do_sigaltstack(frame-uc.tuc_stack, NULL, get_sp_from_cpustate(env)) == -EFAULT)
goto badframe;
- /* It is more difficult to avoid calling this
