diff mbox series

[for-6.2,6/7] linux-user/arm: Use force_sig_fault()

Message ID 20210813131809.28655-7-peter.maydell@linaro.org
State Superseded
Headers show
Series linux-user: Clean up siginfo_t handling for arm, aarch64 | expand

Commit Message

Peter Maydell Aug. 13, 2021, 1:18 p.m. UTC 
Use the new force_sig_fault() function instead of setting up
a target_siginfo_t and calling queue_signal().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

---
I threw in a comment confirming that the si_addr value for the "bad
SWI immediate" SIGILL really is different from the PC value reported
in the ucontext_t and resumed from if the handler returns, because it
looked like a bug to me when I was reading the code...
---
 linux-user/arm/cpu_loop.c | 54 ++++++++++++---------------------------
 1 file changed, 16 insertions(+), 38 deletions(-)

-- 
2.20.1

Comments

Richard Henderson Aug. 15, 2021, 8:25 p.m. UTC | #1 
On 8/13/21 3:18 AM, Peter Maydell wrote:
> Use the new force_sig_fault() function instead of setting up

> a target_siginfo_t and calling queue_signal().

> 

> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>

> ---

> I threw in a comment confirming that the si_addr value for the "bad

> SWI immediate" SIGILL really is different from the PC value reported

> in the ucontext_t and resumed from if the handler returns, because it

> looked like a bug to me when I was reading the code...

> ---

>   linux-user/arm/cpu_loop.c | 54 ++++++++++++---------------------------

>   1 file changed, 16 insertions(+), 38 deletions(-)


Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~
diff mbox series

Patch

diff --git a/linux-user/arm/cpu_loop.c b/linux-user/arm/cpu_loop.c
index 44324976196..d4b4f0c71fc 100644
--- a/linux-user/arm/cpu_loop.c
+++ b/linux-user/arm/cpu_loop.c
@@ -22,6 +22,7 @@ 
 #include "qemu.h"
 #include "elf.h"
 #include "cpu_loop-common.h"
+#include "signal-common.h"
 #include "semihosting/common-semi.h"
 
 #define get_user_code_u32(x, gaddr, env)                \
@@ -92,7 +93,6 @@  static void arm_kernel_cmpxchg64_helper(CPUARMState *env)
 {
     uint64_t oldval, newval, val;
     uint32_t addr, cpsr;
-    target_siginfo_t info;
 
     /* Based on the 32 bit code in do_kernel_trap */
 
@@ -141,12 +141,9 @@  segv:
     end_exclusive();
     /* We get the PC of the entry address - which is as good as anything,
        on a real kernel what you get depends on which mode it uses. */
-    info.si_signo = TARGET_SIGSEGV;
-    info.si_errno = 0;
     /* XXX: check env->error_code */
-    info.si_code = TARGET_SEGV_MAPERR;
-    info._sifields._sigfault._addr = env->exception.vaddress;
-    queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
+    force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_MAPERR,
+                    env->exception.vaddress);
 }
 
 /* Handle a jump to the kernel code page.  */
@@ -284,8 +281,6 @@  void cpu_loop(CPUARMState *env)
     CPUState *cs = env_cpu(env);
     int trapnr;
     unsigned int n, insn;
-    target_siginfo_t info;
-    uint32_t addr;
     abi_ulong ret;
 
     for(;;) {
@@ -320,11 +315,8 @@  void cpu_loop(CPUARMState *env)
                     break;
                 }
 
-                info.si_signo = TARGET_SIGILL;
-                info.si_errno = 0;
-                info.si_code = TARGET_ILL_ILLOPN;
-                info._sifields._sigfault._addr = env->regs[15];
-                queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
+                force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPN,
+                                env->regs[15]);
             }
             break;
         case EXCP_SWI:
@@ -392,18 +384,14 @@  void cpu_loop(CPUARMState *env)
                              * Otherwise SIGILL. This includes any SWI with
                              * immediate not originally 0x9fxxxx, because
                              * of the earlier XOR.
+                             * Like the real kernel, we report the addr of the
+                             * SWI in the siginfo si_addr but leave the PC
+                             * pointing at the insn after the SWI.
                              */
-                            info.si_signo = TARGET_SIGILL;
-                            info.si_errno = 0;
-                            info.si_code = TARGET_ILL_ILLTRP;
-                            info._sifields._sigfault._addr = env->regs[15];
-                            if (env->thumb) {
-                                info._sifields._sigfault._addr -= 2;
-                            } else {
-                                info._sifields._sigfault._addr -= 4;
-                            }
-                            queue_signal(env, info.si_signo,
-                                         QEMU_SI_FAULT, &info);
+                            abi_ulong faultaddr = env->regs[15];
+                            faultaddr -= env->thumb ? 2 : 4;
+                            force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLTRP,
+                                            faultaddr);
                         }
                         break;
                     }
@@ -434,24 +422,14 @@  void cpu_loop(CPUARMState *env)
             break;
         case EXCP_PREFETCH_ABORT:
         case EXCP_DATA_ABORT:
-            addr = env->exception.vaddress;
-            {
-                info.si_signo = TARGET_SIGSEGV;
-                info.si_errno = 0;
-                /* XXX: check env->error_code */
-                info.si_code = TARGET_SEGV_MAPERR;
-                info._sifields._sigfault._addr = addr;
-                queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
-            }
+            /* XXX: check env->error_code */
+            force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_MAPERR,
+                            env->exception.vaddress);
             break;
         case EXCP_DEBUG:
         case EXCP_BKPT:
         excp_debug:
-            info.si_signo = TARGET_SIGTRAP;
-            info.si_errno = 0;
-            info.si_code = TARGET_TRAP_BRKPT;
-            info._sifields._sigfault._addr = env->regs[15];
-            queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
+            force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->regs[15]);
             break;
         case EXCP_KERNEL_TRAP:
             if (do_kernel_trap(env))