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| author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2021-10-18 00:43:23 +0200 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2021-10-18 00:50:41 +0200 |
| commit | 1d20f33ff4fb634310f27493b7b87d0b20f4a0b0 (patch) | |
| tree | 9155e9f1f1417168e8783c4fa97120ac181fe501 /sysdeps | |
| parent | 9d3c9a046a2d7cfc9cad18675612e5916c65d7d7 (diff) | |
| download | glibc-1d20f33ff4fb634310f27493b7b87d0b20f4a0b0.tar.gz glibc-1d20f33ff4fb634310f27493b7b87d0b20f4a0b0.tar.xz glibc-1d20f33ff4fb634310f27493b7b87d0b20f4a0b0.zip | |
hurd: Fix intr-msg parameter/stack kludge
INTR_MSG_TRAP was tinkering with esp to make it point to _hurd_intr_rpc_mach_msg's parameters, and notably use (&msg)[-1] which is meaningless in C. Instead, just push the parameters on the stack, which also avoids leaving local variables of _hurd_intr_rpc_mach_msg below esp. We now also properly express that OPTION and TIMEOUT may be updated during the trap call.
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/mach/hurd/i386/intr-msg.h | 49 |
1 files changed, 39 insertions, 10 deletions
diff --git a/sysdeps/mach/hurd/i386/intr-msg.h b/sysdeps/mach/hurd/i386/intr-msg.h index bd94aaf65f..ac3e5c07ed 100644 --- a/sysdeps/mach/hurd/i386/intr-msg.h +++ b/sysdeps/mach/hurd/i386/intr-msg.h @@ -21,8 +21,6 @@ to indicate that the signal thread might mutate them as part of sending us to a signal handler. */ -/* 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, intr_port_p) \ ({ \ error_t err; \ @@ -31,21 +29,52 @@ ".globl _hurd_intr_rpc_msg_do_trap\n" \ ".globl _hurd_intr_rpc_msg_in_trap\n" \ ".globl _hurd_intr_rpc_msg_sp_restored\n" \ - "_hurd_intr_rpc_msg_about_to: cmpl $0, %5\n" \ + "_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. */ \ + " cmpl $0, %5\n" \ " jz _hurd_intr_rpc_msg_do\n" \ + /* We got interrupted, note so and return EINTR. */ \ " movl $0, %3\n" \ " movl %6, %%eax\n" \ " jmp _hurd_intr_rpc_msg_sp_restored\n" \ - "_hurd_intr_rpc_msg_do: movl %%esp, %%ecx\n" \ - " .cfi_def_cfa_register %%ecx\n" \ - " leal %4, %%esp\n" \ + "_hurd_intr_rpc_msg_do:" \ + /* Ok, push the mach_msg_trap arguments. */ \ + " pushl 24(%4)\n" \ + " .cfi_adjust_cfa_offset 4\n" \ + " pushl %2\n" \ + " .cfi_adjust_cfa_offset 4\n" \ + " pushl 16(%4)\n" \ + " .cfi_adjust_cfa_offset 4\n" \ + " pushl 12(%4)\n" \ + " .cfi_adjust_cfa_offset 4\n" \ + " pushl 8(%4)\n" \ + " .cfi_adjust_cfa_offset 4\n" \ + " pushl %1\n" \ + " .cfi_adjust_cfa_offset 4\n" \ + " pushl (%4)\n" \ + " .cfi_adjust_cfa_offset 4\n" \ + " pushl $0\n" \ + " .cfi_adjust_cfa_offset 4\n" \ + /* TODO: remove this ecx kludge, we don't need it any more */ \ + " movl %%esp, %%ecx\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" \ - " .cfi_def_cfa_register %%esp\n" \ + "_hurd_intr_rpc_msg_in_trap:" \ + /* Ok, clean the arguments and update OPTION and TIMEOUT. */ \ + " addl $8, %%esp\n" \ + " .cfi_adjust_cfa_offset -8\n" \ + " popl %1\n" \ + " .cfi_adjust_cfa_offset -4\n" \ + " addl $12, %%esp\n" \ + " .cfi_adjust_cfa_offset -12\n" \ + " popl %2\n" \ + " .cfi_adjust_cfa_offset -4\n" \ + " addl $4, %%esp\n" \ + " .cfi_adjust_cfa_offset -4\n" \ "_hurd_intr_rpc_msg_sp_restored:" \ - : "=a" (err), "+m" (option), "+m" (timeout), "=m" (*intr_port_p) \ - : "m" ((&msg)[-1]), "m" (*cancel_p), "i" (EINTR) \ + : "=a" (err), "+r" (option), "+r" (timeout), "=m" (*intr_port_p) \ + : "r" (&msg), "m" (*cancel_p), "i" (EINTR) \ : "ecx"); \ err; \ }) |