From a5f6096c805e6d2fa03ee932f8c70af34cee41a0 Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Tue, 16 Oct 2007 01:27:15 -0700 Subject: uml: floating point signal delivery fixes Handle floating point state in across signals correctly. UML/i386 needs to know whether the host does PTRACE_[GS]ETFPXREGS, so an arch_init_registers hook is added, which on x86_64 does nothing. UML doesn't save and restore floating point registers on kernel entry and exit, so they need to be copied between the host process and the sigcontext. save_fpx_registers and restore_fpx_registers are added for this purpose. save_fp_registers and restore_fp_registers already exist. There was a bunch of floating point state conversion code in arch/um/sys-i386/ptrace.c which isn't needed there, but is needed in signal.c, so it is moved over. The i386 code now distinguishes between fp and fpx state and handles them correctly. The x86_64 code just needs to copy state as-is between the host process and the stack. There are also some fixes there to pass the correct address of the floating point state around. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/sys-i386/ptrace.c | 79 ----------------------------------------------- 1 file changed, 79 deletions(-) (limited to 'arch/um/sys-i386/ptrace.c') diff --git a/arch/um/sys-i386/ptrace.c b/arch/um/sys-i386/ptrace.c index 178f894..cb899dd 100644 --- a/arch/um/sys-i386/ptrace.c +++ b/arch/um/sys-i386/ptrace.c @@ -144,85 +144,6 @@ int peek_user(struct task_struct *child, long addr, long data) return put_user(tmp, (unsigned long __user *) data); } -struct i387_fxsave_struct { - unsigned short cwd; - unsigned short swd; - unsigned short twd; - unsigned short fop; - long fip; - long fcs; - long foo; - long fos; - long mxcsr; - long reserved; - long st_space[32]; /* 8*16 bytes for each FP-reg = 128 bytes */ - long xmm_space[32]; /* 8*16 bytes for each XMM-reg = 128 bytes */ - long padding[56]; -}; - -/* - * FPU tag word conversions. - */ - -static inline unsigned short twd_i387_to_fxsr( unsigned short twd ) -{ - unsigned int tmp; /* to avoid 16 bit prefixes in the code */ - - /* Transform each pair of bits into 01 (valid) or 00 (empty) */ - tmp = ~twd; - tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */ - /* and move the valid bits to the lower byte. */ - tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */ - tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */ - tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */ - return tmp; -} - -static inline unsigned long twd_fxsr_to_i387( struct i387_fxsave_struct *fxsave ) -{ - struct _fpxreg *st = NULL; - unsigned long twd = (unsigned long) fxsave->twd; - unsigned long tag; - unsigned long ret = 0xffff0000; - int i; - -#define FPREG_ADDR(f, n) ((char *)&(f)->st_space + (n) * 16); - - for ( i = 0 ; i < 8 ; i++ ) { - if ( twd & 0x1 ) { - st = (struct _fpxreg *) FPREG_ADDR( fxsave, i ); - - switch ( st->exponent & 0x7fff ) { - case 0x7fff: - tag = 2; /* Special */ - break; - case 0x0000: - if ( !st->significand[0] && - !st->significand[1] && - !st->significand[2] && - !st->significand[3] ) { - tag = 1; /* Zero */ - } else { - tag = 2; /* Special */ - } - break; - default: - if ( st->significand[3] & 0x8000 ) { - tag = 0; /* Valid */ - } else { - tag = 2; /* Special */ - } - break; - } - } else { - tag = 3; /* Empty */ - } - ret |= (tag << (2 * i)); - twd = twd >> 1; - } - return ret; -} - static inline int convert_fxsr_to_user(struct _fpstate __user *buf, struct pt_regs *regs) { -- cgit v1.1