From b8ae597f0e6df9d1d80e07083fabf763fcb46013 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 5 Nov 2020 21:23:12 +0000 Subject: [PATCH] linux-user/sparc: Fix errors in target_ucontext structures The various structs that make up the SPARC target_ucontext had some errors: * target structures must not include fields which are host pointers, which might be the wrong size. These should be abi_ulong instead * because we don't have the 'long double' part of the mcfpu_fregs union in our version of the target_mc_fpu struct, we need to manually force it to be 16-aligned In particular, the lack of 16-alignment caused sparc64_get_context() and sparc64_set_context() to read and write all the registers at the wrong offset, which triggered a guest glibc stack check in siglongjmp: *** longjmp causes uninitialized stack frame ***: terminated when trying to run bash. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-Id: <20201105212314.9628-2-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/sparc/signal.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/linux-user/sparc/signal.c b/linux-user/sparc/signal.c index d796f50f66..57ea1593bf 100644 --- a/linux-user/sparc/signal.c +++ b/linux-user/sparc/signal.c @@ -349,10 +349,15 @@ typedef abi_ulong target_mc_greg_t; typedef target_mc_greg_t target_mc_gregset_t[SPARC_MC_NGREG]; struct target_mc_fq { - abi_ulong *mcfq_addr; + abi_ulong mcfq_addr; uint32_t mcfq_insn; }; +/* + * Note the manual 16-alignment; the kernel gets this because it + * includes a "long double qregs[16]" in the mcpu_fregs union, + * which we can't do. + */ struct target_mc_fpu { union { uint32_t sregs[32]; @@ -362,11 +367,11 @@ struct target_mc_fpu { abi_ulong mcfpu_fsr; abi_ulong mcfpu_fprs; abi_ulong mcfpu_gsr; - struct target_mc_fq *mcfpu_fq; + abi_ulong mcfpu_fq; unsigned char mcfpu_qcnt; unsigned char mcfpu_qentsz; unsigned char mcfpu_enab; -}; +} __attribute__((aligned(16))); typedef struct target_mc_fpu target_mc_fpu_t; typedef struct { @@ -377,7 +382,7 @@ typedef struct { } target_mcontext_t; struct target_ucontext { - struct target_ucontext *tuc_link; + abi_ulong tuc_link; abi_ulong tuc_flags; target_sigset_t tuc_sigmask; target_mcontext_t tuc_mcontext;