openssl
/
openssl
mirror of https://github.com/openssl/openssl
1
0
Fork 0
Code Issues Releases Wiki Activity

Make the ASYNC code default libctx aware 

Since the default libctx is now stored in a thread local variable
swapping in and out of fibres in the ASYNC code could mean that the
"current" default libctx can get confused. Therefore we ensure that
everytime we call async_fibre_swapcontext() we always restore the default
libctx to whatever it was the last time the fibre ran. Similarly when
async_fibre_swapcontext() returns we need to restore the current thread's
default libctx.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/12228)
This commit is contained in:
Matt Caswell 2020-06-26 11:00:25 +01:00 committed by Richard Levitte
parent cfbd76c1a9
commit 6c689e58f7
3 changed files with 27 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
crypto/async/async.c
View File

@ -170,6 +170,7 @@ int ASYNC_start_job(ASYNC_JOB **job, ASYNC_WAIT_CTX *wctx, int *ret,
int (*func)(void *), void *args, size_t size)
{
async_ctx *ctx;
OPENSSL_CTX *libctx;
if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
return ASYNC_ERR;
@ -203,6 +204,11 @@ int ASYNC_start_job(ASYNC_JOB **job, ASYNC_WAIT_CTX *wctx, int *ret,
if (ctx->currjob->status == ASYNC_JOB_PAUSED) {
ctx->currjob = *job;
/*
* Restore the default libctx to what it was the last time the
* fibre ran
*/
libctx = OPENSSL_CTX_set0_default(ctx->currjob->libctx);
/* Resume previous job */
if (!async_fibre_swapcontext(&ctx->dispatcher,
&ctx->currjob->fibrectx, 1)) {
@ -210,6 +216,12 @@ int ASYNC_start_job(ASYNC_JOB **job, ASYNC_WAIT_CTX *wctx, int *ret,
ASYNC_R_FAILED_TO_SWAP_CONTEXT);
goto err;
}
/*
* In case the fibre changed the default libctx we set it back
* again to what it was originally, and remember what it had
* been changed to.
*/
ctx->currjob->libctx = OPENSSL_CTX_set0_default(libctx);
continue;
}
@ -240,11 +252,17 @@ int ASYNC_start_job(ASYNC_JOB **job, ASYNC_WAIT_CTX *wctx, int *ret,
ctx->currjob->func = func;
ctx->currjob->waitctx = wctx;
libctx = openssl_ctx_get_concrete(NULL);
if (!async_fibre_swapcontext(&ctx->dispatcher,
&ctx->currjob->fibrectx, 1)) {
ASYNCerr(ASYNC_F_ASYNC_START_JOB, ASYNC_R_FAILED_TO_SWAP_CONTEXT);
goto err;
}
/*
* In case the fibre changed the default libctx we set it back again
* to what it was, and remember what it had been changed to.
*/
ctx->currjob->libctx = OPENSSL_CTX_set0_default(libctx);
}
err:

1
crypto/async/async_local.h
View File

@ -43,6 +43,7 @@ struct async_job_st {
int ret;
int status;
ASYNC_WAIT_CTX *waitctx;
OPENSSL_CTX *libctx;
};
struct fd_lookup_st {

8
doc/man3/OPENSSL_CTX.pod
View File

@ -43,6 +43,14 @@ I<ctx> in the current thread. The previous default library context is
returned. Care should be taken by the caller to restore the previous
default library context with a subsequent call of this function.
Care should be taken when changing the default library context and starting
async jobs (see L<ASYNC_start_job(3)>), as the default library context when
the job is started will be used throughout the lifetime of an async job, no
matter how the calling thread makes further default library context changes
in the mean time. This means that the calling thread must not free the
library context that was the default at the start of the async job before
that job has finished.
=head1 RETURN VALUES
OPENSSL_CTX_new() and OPENSSL_CTX_set0_default() return a library context