diff options
| author | kib <kib@FreeBSD.org> | 2014-06-23 07:37:54 +0000 |
|---|---|---|
| committer | kib <kib@FreeBSD.org> | 2014-06-23 07:37:54 +0000 |
| commit | fe547198b1973809825a6d6e48d12cf6f1c93741 (patch) | |
| tree | a51002de5281f8a64709f9e315f0f0337d66108c /sys/amd64 | |
| parent | c2a4e94982dc22b2ff3eb85b284839f96f217faf (diff) | |
| download | FreeBSD-src-fe547198b1973809825a6d6e48d12cf6f1c93741.zip FreeBSD-src-fe547198b1973809825a6d6e48d12cf6f1c93741.tar.gz | |
Add FPU_KERN_KTHR flag to fpu_kern_enter(9), which avoids saving FPU
context into memory for the kernel threads which called
fpu_kern_thread(9). This allows the fpu_kern_enter() callers to not
check for is_fpu_kern_thread() to get the optimization.
Apply the flag to padlock(4) and aesni(4). In aesni_cipher_process(),
do not leak FPU context state on error.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Diffstat (limited to 'sys/amd64')
| -rw-r--r-- | sys/amd64/amd64/fpu.c | 8 | ||||
| -rw-r--r-- | sys/amd64/include/fpu.h | 1 |
2 files changed, 9 insertions, 0 deletions
diff --git a/sys/amd64/amd64/fpu.c b/sys/amd64/amd64/fpu.c index d2d506a..0f4b2b5 100644 --- a/sys/amd64/amd64/fpu.c +++ b/sys/amd64/amd64/fpu.c @@ -890,6 +890,7 @@ static MALLOC_DEFINE(M_FPUKERN_CTX, "fpukern_ctx", "Kernel contexts for FPU state"); #define FPU_KERN_CTX_FPUINITDONE 0x01 +#define FPU_KERN_CTX_DUMMY 0x02 /* avoided save for the kern thread */ struct fpu_kern_ctx { struct savefpu *prev; @@ -933,6 +934,10 @@ fpu_kern_enter(struct thread *td, struct fpu_kern_ctx *ctx, u_int flags) { struct pcb *pcb; + if ((flags & FPU_KERN_KTHR) != 0 && is_fpu_kern_thread(0)) { + ctx->flags = FPU_KERN_CTX_DUMMY; + return (0); + } pcb = td->td_pcb; KASSERT(!PCB_USER_FPU(pcb) || pcb->pcb_save == get_pcb_user_save_pcb(pcb), ("mangled pcb_save")); @@ -952,6 +957,9 @@ fpu_kern_leave(struct thread *td, struct fpu_kern_ctx *ctx) { struct pcb *pcb; + if (is_fpu_kern_thread(0) && (ctx->flags & FPU_KERN_CTX_DUMMY) != 0) + return (0); + KASSERT((ctx->flags & FPU_KERN_CTX_DUMMY) == 0, ("dummy ctx")); pcb = td->td_pcb; critical_enter(); if (curthread == PCPU_GET(fpcurthread)) diff --git a/sys/amd64/include/fpu.h b/sys/amd64/include/fpu.h index ef5d623..be1bdc6 100644 --- a/sys/amd64/include/fpu.h +++ b/sys/amd64/include/fpu.h @@ -84,6 +84,7 @@ void fpu_save_area_reset(struct savefpu *fsa); */ #define FPU_KERN_NORMAL 0x0000 #define FPU_KERN_NOWAIT 0x0001 +#define FPU_KERN_KTHR 0x0002 #endif |
