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qemu / qemu / fcf83ab103dce6d2951f24f48e30820e7dbb3622
commitfcf83ab103dce6d2951f24f48e30820e7dbb3622[log] [tgz]
authorPeter Maydell <peter.maydell@linaro.org>Mon Mar 16 12:30:47 2015 +0000
committerPeter Maydell <peter.maydell@linaro.org>Mon Mar 16 12:30:47 2015 +0000
tree45fd7842e9c64372faca50d236807dce7b11c362
parentda3e53ddcb0ca924da97ca5a35605fc554aa3e05 [diff]
target-arm: Ignore low bit of PC in M-profile exception return

For the ARM M-profile cores, exception return pops various registers
including the PC from the stack. The architecture defines that if the
lowest bit in the new PC value is set (ie the PC is not halfword
aligned) then behaviour is UNPREDICTABLE. In practice hardware
implementations seem to simply ignore the low bit, and some buggy
RTOSes incorrectly rely on this. QEMU's behaviour was architecturally
permitted, but bringing QEMU into line with the hardware behaviour
allows more guest code to run. We log the situation as a guest error.

This was reported as LP:1428657.

Reported-by: Anders Esbensen <anders@lyes.dk>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
1 file changed
tree: 45fd7842e9c64372faca50d236807dce7b11c362
  1. audio/
  2. backends/
  3. block/
  4. bsd-user/
  5. default-configs/
  6. disas/
  7. docs/
  8. fpu/
  9. fsdev/
  10. gdb-xml/
  11. hw/
  12. include/
  13. libcacard/
  14. libdecnumber/
  15. linux-headers/
  16. linux-user/
  17. migration/
  18. net/
  19. pc-bios/
  20. po/
  21. qapi/
  22. qga/
  23. qobject/
  24. qom/
  25. roms/
  26. scripts/
  27. slirp/
  28. stubs/
  29. sysconfigs/
  30. target-alpha/
  31. target-arm/
  32. target-cris/
  33. target-i386/
  34. target-lm32/
  35. target-m68k/
  36. target-microblaze/
  37. target-mips/
  38. target-moxie/
  39. target-openrisc/
  40. target-ppc/
  41. target-s390x/
  42. target-sh4/
  43. target-sparc/
  44. target-tricore/
  45. target-unicore32/
  46. target-xtensa/
  47. tcg/
  48. tests/
  49. trace/
  50. ui/
  51. util/
  52. dtc
  53. pixman
  54. .exrc
  55. .gitignore
  56. .gitmodules
  57. .mailmap
  58. .travis.yml
  59. accel.c
  60. aio-posix.c
  61. aio-win32.c
  62. arch_init.c
  63. async.c
  64. balloon.c
  65. block.c
  66. blockdev-nbd.c
  67. blockdev.c
  68. blockjob.c
  69. bootdevice.c
  70. bt-host.c
  71. bt-vhci.c
  72. Changelog
  73. CODING_STYLE
  74. configure
  75. COPYING
  76. COPYING.LIB
  77. coroutine-gthread.c
  78. coroutine-sigaltstack.c
  79. coroutine-ucontext.c
  80. coroutine-win32.c
  81. cpu-exec.c
  82. cpus.c
  83. cputlb.c
  84. device-hotplug.c
  85. device_tree.c
  86. disas.c
  87. dma-helpers.c
  88. dump.c
  89. exec.c
  90. gdbstub.c
  91. HACKING
  92. hmp-commands.hx
  93. hmp.c
  94. hmp.h
  95. iohandler.c
  96. ioport.c
  97. iothread.c
  98. kvm-all.c
  99. kvm-stub.c
  100. LICENSE
  101. main-loop.c
  102. MAINTAINERS
  103. Makefile
  104. Makefile.objs
  105. Makefile.target
  106. memory.c
  107. memory_mapping.c
  108. module-common.c
  109. monitor.c
  110. nbd.c
  111. numa.c
  112. os-posix.c
  113. os-win32.c
  114. page_cache.c
  115. qapi-schema.json
  116. qdev-monitor.c
  117. qdict-test-data.txt
  118. qemu-bridge-helper.c
  119. qemu-char.c
  120. qemu-coroutine-io.c
  121. qemu-coroutine-lock.c
  122. qemu-coroutine-sleep.c
  123. qemu-coroutine.c
  124. qemu-doc.texi
  125. qemu-img-cmds.hx
  126. qemu-img.c
  127. qemu-img.texi
  128. qemu-io-cmds.c
  129. qemu-io.c
  130. qemu-log.c
  131. qemu-nbd.c
  132. qemu-nbd.texi
  133. qemu-options-wrapper.h
  134. qemu-options.h
  135. qemu-options.hx
  136. qemu-seccomp.c
  137. qemu-tech.texi
  138. qemu-timer.c
  139. qemu.nsi
  140. qemu.sasl
  141. qjson.c
  142. qmp-commands.hx
  143. qmp.c
  144. qtest.c
  145. README
  146. rules.mak
  147. savevm.c
  148. softmmu_template.h
  149. spice-qemu-char.c
  150. tcg-runtime.c
  151. tci.c
  152. thread-pool.c
  153. thunk.c
  154. tpm.c
  155. trace-events
  156. translate-all.c
  157. translate-all.h
  158. user-exec.c
  159. VERSION
  160. version.rc
  161. vl.c
  162. xen-common-stub.c
  163. xen-common.c
  164. xen-hvm-stub.c
  165. xen-hvm.c
  166. xen-mapcache.c