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| author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2018-10-09 23:40:09 +0200 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2018-10-28 10:26:01 +0100 |
| commit | 32ad5b3328e0ce53ca27e185a89ca44c1d0acd0c (patch) | |
| tree | 6987a11aa93afba1de0aed2cb70d8bb7a201bf3f /sysdeps | |
| parent | 2d0d1d38761cd9aeb7063c5cce1993cec909f67f (diff) | |
| download | glibc-32ad5b3328e0ce53ca27e185a89ca44c1d0acd0c.zip glibc-32ad5b3328e0ce53ca27e185a89ca44c1d0acd0c.tar.gz glibc-32ad5b3328e0ce53ca27e185a89ca44c1d0acd0c.tar.bz2 | |
hurd: Fix race between calling RPC and handling a signal
* sysdeps/mach/hurd/i386/intr-msg.h (INTR_MSG_TRAP): Make
_hurd_intr_rpc_msg_about_to global point to start of controlled
assembly snippet. Make it check canceled flag again.
* hurd/hurdsig.c (_hurdsig_abort_rpcs): Only mutate thread if it passed the
_hurd_intr_rpc_msg_about_to point.
* hurd/intr-msg.c (_hurd_intr_rpc_mach_msg): Remove comment on mutation
issue.
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/mach/hurd/i386/intr-msg.h | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/sysdeps/mach/hurd/i386/intr-msg.h b/sysdeps/mach/hurd/i386/intr-msg.h index 64f05f8..baa9ba9 100644 --- a/sysdeps/mach/hurd/i386/intr-msg.h +++ b/sysdeps/mach/hurd/i386/intr-msg.h @@ -20,21 +20,29 @@ /* Note that we must mark OPTION and TIMEOUT as outputs of this operation, to indicate that the signal thread might mutate them as part of sending us to a signal handler. */ -#define INTR_MSG_TRAP(msg, option, send_size, rcv_size, rcv_name, timeout, notify) \ + +/* After _hurd_intr_rpc_msg_about_to we need to make a last check of cancel, in + case we got interrupted right before _hurd_intr_rpc_msg_about_to. */ +#define INTR_MSG_TRAP(msg, option, send_size, rcv_size, rcv_name, timeout, notify, cancel_p) \ ({ \ error_t err; \ - asm (".globl _hurd_intr_rpc_msg_do_trap\n" \ - ".globl _hurd_intr_rpc_msg_in_trap\n" \ + asm (".globl _hurd_intr_rpc_msg_about_to\n" \ ".globl _hurd_intr_rpc_msg_cx_sp\n" \ + ".globl _hurd_intr_rpc_msg_do_trap\n" \ + ".globl _hurd_intr_rpc_msg_in_trap\n" \ ".globl _hurd_intr_rpc_msg_sp_restored\n" \ - " movl %%esp, %%ecx\n" \ + "_hurd_intr_rpc_msg_about_to: cmpl $0, %4\n" \ + " jz _hurd_intr_rpc_msg_do\n" \ + " movl %5, %%eax\n" \ + " jmp _hurd_intr_rpc_msg_sp_restored\n" \ + "_hurd_intr_rpc_msg_do: movl %%esp, %%ecx\n" \ " leal %3, %%esp\n" \ "_hurd_intr_rpc_msg_cx_sp: movl $-25, %%eax\n" \ "_hurd_intr_rpc_msg_do_trap: lcall $7, $0 # status in %0\n" \ "_hurd_intr_rpc_msg_in_trap: movl %%ecx, %%esp\n" \ "_hurd_intr_rpc_msg_sp_restored:" \ : "=a" (err), "+m" (option), "+m" (timeout) \ - : "m" ((&msg)[-1]) \ + : "m" ((&msg)[-1]), "m" (*cancel_p), "i" (EINTR) \ : "ecx"); \ err; \ }) |