* [PATCH] tcg: Use correct trap number for page faults on *BSD systems
@ 2021-05-06 16:42 Warner Losh
2021-05-06 17:35 ` Warner Losh
0 siblings, 1 reply; 2+ messages in thread
From: Warner Losh @ 2021-05-06 16:42 UTC (permalink / raw)
To: qemu-devel
Cc: kevans, Riku Voipio, Richard Henderson, Mark Johnston,
Juergen Lock, Paolo Bonzini, Warner Losh
The trap number for a page fault on BSD systems is T_PAGEFLT not 0xe. 0xe is
used by Linux and represents the intel hardware trap vector. The BSD kernels,
however, translate this to T_PAGEFLT in their Xpage, Xtrap0e, Xtrap14, etc fault
handlers. This is true for i386 and x86_64, though the name of the trap hanlder
can very on the flavor of BSD. As far as I can tell, Linux doesn't provide a
avoid uglier #ifdefs.
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Signed-off-by: Juergen Lock <nox@FreeBSD.org>
[ Rework to avoid ifdefs and expand it to i386 ]
Signed-off-by: Warner Losh <imp@bsdimp.com>
---
accel/tcg/user-exec.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c
index 0d8cc27b21..959fec1257 100644
--- a/accel/tcg/user-exec.c
+++ b/accel/tcg/user-exec.c
@@ -260,6 +260,7 @@ void *probe_access(CPUArchState *env, target_ulong addr, int size,
#define TRAP_sig(context) ((context)->uc_mcontext.__gregs[_REG_TRAPNO])
#define ERROR_sig(context) ((context)->uc_mcontext.__gregs[_REG_ERR])
#define MASK_sig(context) ((context)->uc_sigmask)
+#define PAGE_FAULT_TRAP T_PAGEFLT
#elif defined(__FreeBSD__) || defined(__DragonFly__)
#include <ucontext.h>
@@ -267,16 +268,19 @@ void *probe_access(CPUArchState *env, target_ulong addr, int size,
#define TRAP_sig(context) ((context)->uc_mcontext.mc_trapno)
#define ERROR_sig(context) ((context)->uc_mcontext.mc_err)
#define MASK_sig(context) ((context)->uc_sigmask)
+#define PAGE_FAULT_TRAP T_PAGEFLT
#elif defined(__OpenBSD__)
#define EIP_sig(context) ((context)->sc_eip)
#define TRAP_sig(context) ((context)->sc_trapno)
#define ERROR_sig(context) ((context)->sc_err)
#define MASK_sig(context) ((context)->sc_mask)
+#define PAGE_FAULT_TRAP T_PAGEFLT
#else
#define EIP_sig(context) ((context)->uc_mcontext.gregs[REG_EIP])
#define TRAP_sig(context) ((context)->uc_mcontext.gregs[REG_TRAPNO])
#define ERROR_sig(context) ((context)->uc_mcontext.gregs[REG_ERR])
#define MASK_sig(context) ((context)->uc_sigmask)
+#define PAGE_FAULT_TRAP 0xe
#endif
int cpu_signal_handler(int host_signum, void *pinfo,
@@ -302,7 +306,8 @@ int cpu_signal_handler(int host_signum, void *pinfo,
pc = EIP_sig(uc);
trapno = TRAP_sig(uc);
return handle_cpu_signal(pc, info,
- trapno == 0xe ? (ERROR_sig(uc) >> 1) & 1 : 0,
+ trapno == PAGE_FAULT_TRAP ?
+ (ERROR_sig(uc) >> 1) & 1 : 0,
&MASK_sig(uc));
}
@@ -313,11 +318,13 @@ int cpu_signal_handler(int host_signum, void *pinfo,
#define TRAP_sig(context) ((context)->uc_mcontext.__gregs[_REG_TRAPNO])
#define ERROR_sig(context) ((context)->uc_mcontext.__gregs[_REG_ERR])
#define MASK_sig(context) ((context)->uc_sigmask)
+#define PAGE_FAULT_TRAP T_PAGEFLT
#elif defined(__OpenBSD__)
#define PC_sig(context) ((context)->sc_rip)
#define TRAP_sig(context) ((context)->sc_trapno)
#define ERROR_sig(context) ((context)->sc_err)
#define MASK_sig(context) ((context)->sc_mask)
+#define PAGE_FAULT_TRAP T_PAGEFLT
#elif defined(__FreeBSD__) || defined(__DragonFly__)
#include <ucontext.h>
@@ -325,11 +332,13 @@ int cpu_signal_handler(int host_signum, void *pinfo,
#define TRAP_sig(context) ((context)->uc_mcontext.mc_trapno)
#define ERROR_sig(context) ((context)->uc_mcontext.mc_err)
#define MASK_sig(context) ((context)->uc_sigmask)
+#define PAGE_FAULT_TRAP T_PAGEFLT
#else
#define PC_sig(context) ((context)->uc_mcontext.gregs[REG_RIP])
#define TRAP_sig(context) ((context)->uc_mcontext.gregs[REG_TRAPNO])
#define ERROR_sig(context) ((context)->uc_mcontext.gregs[REG_ERR])
#define MASK_sig(context) ((context)->uc_sigmask)
+#define PAGE_FAULT_TRAP 0xe
#endif
int cpu_signal_handler(int host_signum, void *pinfo,
@@ -347,7 +356,8 @@ int cpu_signal_handler(int host_signum, void *pinfo,
pc = PC_sig(uc);
return handle_cpu_signal(pc, info,
- TRAP_sig(uc) == 0xe ? (ERROR_sig(uc) >> 1) & 1 : 0,
+ TRAP_sig(uc) == PAGE_FAULT_TRAP ?
+ (ERROR_sig(uc) >> 1) & 1 : 0,
&MASK_sig(uc));
}
--
2.22.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] tcg: Use correct trap number for page faults on *BSD systems
2021-05-06 16:42 [PATCH] tcg: Use correct trap number for page faults on *BSD systems Warner Losh
@ 2021-05-06 17:35 ` Warner Losh
0 siblings, 0 replies; 2+ messages in thread
From: Warner Losh @ 2021-05-06 17:35 UTC (permalink / raw)
To: QEMU Developers
Cc: Kyle Evans, Riku Voipio, Richard Henderson, Mark Johnston,
Paolo Bonzini, Juergen Lock
[-- Attachment #1: Type: text/plain, Size: 4829 bytes --]
On Thu, May 6, 2021 at 10:43 AM Warner Losh <imp@bsdimp.com> wrote:
> The trap number for a page fault on BSD systems is T_PAGEFLT not 0xe. 0xe
> is
> used by Linux and represents the intel hardware trap vector. The BSD
> kernels,
> however, translate this to T_PAGEFLT in their Xpage, Xtrap0e, Xtrap14, etc
> fault
> handlers. This is true for i386 and x86_64, though the name of the trap
> hanlder
> can very on the flavor of BSD. As far as I can tell, Linux doesn't provide
> a
>
I've been burned by git's # comments in the commit message. This is missing
a line:
#define for this value. Invent a new one and use it instead to
> avoid uglier #ifdefs.
>
I'll amend and resend.
> Signed-off-by: Mark Johnston <markj@FreeBSD.org>
> Signed-off-by: Juergen Lock <nox@FreeBSD.org>
> [ Rework to avoid ifdefs and expand it to i386 ]
> Signed-off-by: Warner Losh <imp@bsdimp.com>
> ---
> accel/tcg/user-exec.c | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c
> index 0d8cc27b21..959fec1257 100644
> --- a/accel/tcg/user-exec.c
> +++ b/accel/tcg/user-exec.c
> @@ -260,6 +260,7 @@ void *probe_access(CPUArchState *env, target_ulong
> addr, int size,
> #define TRAP_sig(context) ((context)->uc_mcontext.__gregs[_REG_TRAPNO])
> #define ERROR_sig(context) ((context)->uc_mcontext.__gregs[_REG_ERR])
> #define MASK_sig(context) ((context)->uc_sigmask)
> +#define PAGE_FAULT_TRAP T_PAGEFLT
> #elif defined(__FreeBSD__) || defined(__DragonFly__)
> #include <ucontext.h>
>
> @@ -267,16 +268,19 @@ void *probe_access(CPUArchState *env, target_ulong
> addr, int size,
> #define TRAP_sig(context) ((context)->uc_mcontext.mc_trapno)
> #define ERROR_sig(context) ((context)->uc_mcontext.mc_err)
> #define MASK_sig(context) ((context)->uc_sigmask)
> +#define PAGE_FAULT_TRAP T_PAGEFLT
> #elif defined(__OpenBSD__)
> #define EIP_sig(context) ((context)->sc_eip)
> #define TRAP_sig(context) ((context)->sc_trapno)
> #define ERROR_sig(context) ((context)->sc_err)
> #define MASK_sig(context) ((context)->sc_mask)
> +#define PAGE_FAULT_TRAP T_PAGEFLT
> #else
> #define EIP_sig(context) ((context)->uc_mcontext.gregs[REG_EIP])
> #define TRAP_sig(context) ((context)->uc_mcontext.gregs[REG_TRAPNO])
> #define ERROR_sig(context) ((context)->uc_mcontext.gregs[REG_ERR])
> #define MASK_sig(context) ((context)->uc_sigmask)
> +#define PAGE_FAULT_TRAP 0xe
> #endif
>
> int cpu_signal_handler(int host_signum, void *pinfo,
> @@ -302,7 +306,8 @@ int cpu_signal_handler(int host_signum, void *pinfo,
> pc = EIP_sig(uc);
> trapno = TRAP_sig(uc);
> return handle_cpu_signal(pc, info,
> - trapno == 0xe ? (ERROR_sig(uc) >> 1) & 1 : 0,
> + trapno == PAGE_FAULT_TRAP ?
> + (ERROR_sig(uc) >> 1) & 1 : 0,
> &MASK_sig(uc));
> }
>
> @@ -313,11 +318,13 @@ int cpu_signal_handler(int host_signum, void *pinfo,
> #define TRAP_sig(context)
> ((context)->uc_mcontext.__gregs[_REG_TRAPNO])
> #define ERROR_sig(context) ((context)->uc_mcontext.__gregs[_REG_ERR])
> #define MASK_sig(context) ((context)->uc_sigmask)
> +#define PAGE_FAULT_TRAP T_PAGEFLT
> #elif defined(__OpenBSD__)
> #define PC_sig(context) ((context)->sc_rip)
> #define TRAP_sig(context) ((context)->sc_trapno)
> #define ERROR_sig(context) ((context)->sc_err)
> #define MASK_sig(context) ((context)->sc_mask)
> +#define PAGE_FAULT_TRAP T_PAGEFLT
> #elif defined(__FreeBSD__) || defined(__DragonFly__)
> #include <ucontext.h>
>
> @@ -325,11 +332,13 @@ int cpu_signal_handler(int host_signum, void *pinfo,
> #define TRAP_sig(context) ((context)->uc_mcontext.mc_trapno)
> #define ERROR_sig(context) ((context)->uc_mcontext.mc_err)
> #define MASK_sig(context) ((context)->uc_sigmask)
> +#define PAGE_FAULT_TRAP T_PAGEFLT
> #else
> #define PC_sig(context) ((context)->uc_mcontext.gregs[REG_RIP])
> #define TRAP_sig(context) ((context)->uc_mcontext.gregs[REG_TRAPNO])
> #define ERROR_sig(context) ((context)->uc_mcontext.gregs[REG_ERR])
> #define MASK_sig(context) ((context)->uc_sigmask)
> +#define PAGE_FAULT_TRAP 0xe
> #endif
>
> int cpu_signal_handler(int host_signum, void *pinfo,
> @@ -347,7 +356,8 @@ int cpu_signal_handler(int host_signum, void *pinfo,
>
> pc = PC_sig(uc);
> return handle_cpu_signal(pc, info,
> - TRAP_sig(uc) == 0xe ? (ERROR_sig(uc) >> 1) &
> 1 : 0,
> + TRAP_sig(uc) == PAGE_FAULT_TRAP ?
> + (ERROR_sig(uc) >> 1) & 1 : 0,
> &MASK_sig(uc));
> }
>
> --
> 2.22.1
>
>
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