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author | Ralf Baechle <ralf@linux-mips.org> | 2006-02-10 01:31:24 +0000 |
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committer | Ralf Baechle <ralf@linux-mips.org> | 2006-02-14 19:13:24 +0000 |
commit | 3218357c94af92478ef39163163a81e654385320 (patch) | |
tree | 459be556900bb4a78d93e0185d49df8ed8a7aff4 /arch/mips | |
parent | 41700e73995d6c814932cb55e12525bd34be1ca5 (diff) | |
download | op-kernel-dev-3218357c94af92478ef39163163a81e654385320.zip op-kernel-dev-3218357c94af92478ef39163163a81e654385320.tar.gz |
[MIPS] More uaccess.h fixes with gcc >= 4.0.1.
From Richard Sandiford <richard@codesourcery.com>:
This patch caused a miscompilation of the restore_gp_regs() block
in restore_sigcontext(). This was in a 32-bit kernel compiled with
GCC CVS head.
restore_gp_regs() copies 64-bit user fields into 32-bit variables,
and in this combination, the new __get_user_asm_ll32() clobbers too
many registers. It says:
/*
* Get a long long 64 using 32 bit registers.
*/
{ \
__asm__ __volatile__( \
"1: lw %1, (%3) \n" \
"2: lw %D1, 4(%3) \n" \
" move %0, $0 \n" \
"3: .section .fixup,\"ax\" \n" \
"4: li %0, %4 \n" \
" move %1, $0 \n" \
" move %D1, $0 \n" \
" j 3b \n" \
" .previous \n" \
" .section __ex_table,\"a\" \n" \
" " __UA_ADDR " 1b, 4b \n" \
" " __UA_ADDR " 2b, 4b \n" \
" .previous \n" \
: "=r" (__gu_err), "=&r" (val) \
: "0" (0), "r" (addr), "i" (-EFAULT)); \
}
and this requires val (%1) to be a 64-bit value. In the case I saw,
gcc was using $3 for the 32-bit val, and wasn't expecting $4 to be
clobbered.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips')
0 files changed, 0 insertions, 0 deletions