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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2011-01-11 15:10:08 +1100 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2011-01-11 15:10:08 +1100 |
| commit | eed0ba0b4ab2d1668588219a8efa81bf8636a12d (patch) | |
| tree | f5aa3c732e7830a1b24e6071f8bed0f799881187 /arch/tile/kernel/intvec_32.S | |
| parent | 98b14d6b290d96b24ae993ceaccc59b2aa4b130c (diff) | |
| parent | c9de9333f5a860cab82052bce6ac28bcac9b2c26 (diff) | |
| download | linux-eed0ba0b4ab2d1668588219a8efa81bf8636a12d.tar.bz2 | |
Merge remote branch 'gcl/next' into next
Diffstat (limited to 'arch/tile/kernel/intvec_32.S')
| -rw-r--r-- | arch/tile/kernel/intvec_32.S | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/arch/tile/kernel/intvec_32.S b/arch/tile/kernel/intvec_32.S index f5821626247f..5eed4a02bf62 100644 --- a/arch/tile/kernel/intvec_32.S +++ b/arch/tile/kernel/intvec_32.S @@ -1342,8 +1342,8 @@ handle_syscall: lw r20, r20 /* Jump to syscall handler. */ - jalr r20; .Lhandle_syscall_link: - FEEDBACK_REENTER(handle_syscall) + jalr r20 +.Lhandle_syscall_link: /* value of "lr" after "jalr r20" above */ /* * Write our r0 onto the stack so it gets restored instead @@ -1352,6 +1352,9 @@ handle_syscall: PTREGS_PTR(r29, PTREGS_OFFSET_REG(0)) sw r29, r0 +.Lsyscall_sigreturn_skip: + FEEDBACK_REENTER(handle_syscall) + /* Do syscall trace again, if requested. */ lw r30, r31 andi r30, r30, _TIF_SYSCALL_TRACE @@ -1536,9 +1539,24 @@ STD_ENTRY_LOCAL(bad_intr) }; \ STD_ENDPROC(_##x) +/* + * Special-case sigreturn to not write r0 to the stack on return. + * This is technically more efficient, but it also avoids difficulties + * in the 64-bit OS when handling 32-bit compat code, since we must not + * sign-extend r0 for the sigreturn return-value case. + */ +#define PTREGS_SYSCALL_SIGRETURN(x, reg) \ + STD_ENTRY(_##x); \ + addli lr, lr, .Lsyscall_sigreturn_skip - .Lhandle_syscall_link; \ + { \ + PTREGS_PTR(reg, PTREGS_OFFSET_BASE); \ + j x \ + }; \ + STD_ENDPROC(_##x) + PTREGS_SYSCALL(sys_execve, r3) PTREGS_SYSCALL(sys_sigaltstack, r2) -PTREGS_SYSCALL(sys_rt_sigreturn, r0) +PTREGS_SYSCALL_SIGRETURN(sys_rt_sigreturn, r0) PTREGS_SYSCALL(sys_cmpxchg_badaddr, r1) /* Save additional callee-saves to pt_regs, put address in r4 and jump. */ |