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Re: [Qemu-devel] [PATCH 1/4] w64: Fix TCG helper functions with 5 argume
From: |
Aurelien Jarno |
Subject: |
Re: [Qemu-devel] [PATCH 1/4] w64: Fix TCG helper functions with 5 arguments |
Date: |
Thu, 13 Sep 2012 23:22:00 +0200 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Thu, Sep 13, 2012 at 07:37:43PM +0200, Stefan Weil wrote:
> TCG uses 6 registers for function arguments on 64 bit Linux hosts,
> but only 4 registers on W64 hosts.
>
> Commit 2999a0b20074a7e4a58f56572bb1436749368f59 increased the number
> of arguments for some important helper functions from 4 to 5
> which triggered a bug for W64 hosts: QEMU aborts when executing
> helper_lcall_real in the guest's BIOS because function
> tcg_target_get_call_iarg_regs_count always returned 6.
>
> As W64 has only 4 registers for arguments, the 5th argument must be
> passed on the stack using a correct stack offset.
>
> Signed-off-by: Stefan Weil <address@hidden>
> ---
> tcg/i386/tcg-target.c | 2 +-
> tcg/i386/tcg-target.h | 4 ++++
> 2 files changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
> index da17bba..43b5572 100644
> --- a/tcg/i386/tcg-target.c
> +++ b/tcg/i386/tcg-target.c
> @@ -118,7 +118,7 @@ static void patch_reloc(uint8_t *code_ptr, int type,
> static inline int tcg_target_get_call_iarg_regs_count(int flags)
> {
> if (TCG_TARGET_REG_BITS == 64) {
> - return 6;
> + return ARRAY_SIZE(tcg_target_call_iarg_regs);
> }
>
> return 0;
> diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h
> index c3cfe05..87417d0 100644
> --- a/tcg/i386/tcg-target.h
> +++ b/tcg/i386/tcg-target.h
> @@ -67,7 +67,11 @@ typedef enum {
> /* used for function call generation */
> #define TCG_REG_CALL_STACK TCG_REG_ESP
> #define TCG_TARGET_STACK_ALIGN 16
> +#if defined(_WIN64)
> +#define TCG_TARGET_CALL_STACK_OFFSET 32
> +#else
> #define TCG_TARGET_CALL_STACK_OFFSET 0
> +#endif
>
> /* optional instructions */
> #define TCG_TARGET_HAS_div2_i32 1
> --
> 1.7.10
>
>
Reviewed-by: Aurelien Jarno <address@hidden>
--
Aurelien Jarno GPG: 1024D/F1BCDB73
address@hidden http://www.aurel32.net
- Re: [Qemu-devel] [PATCH 2/4] tcg/i386: Add shortcuts for registers used in L constraint, (continued)
[Qemu-devel] [PATCH 3/4] tcg/i386: Remove unused registers from tcg_target_call_iarg_regs, Stefan Weil, 2012/09/13
[Qemu-devel] [PATCH 4/4] tcg: Remove tcg_target_get_call_iarg_regs_count, Stefan Weil, 2012/09/13
[Qemu-devel] [PATCH 1/4] w64: Fix TCG helper functions with 5 arguments, Stefan Weil, 2012/09/13
Re: [Qemu-devel] [PATCH v2 0/4] Fix and clean tcg_target_get_call_iarg_regs_count, Richard Henderson, 2012/09/13