summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/dumpstack.c
diff options
context:
space:
mode:
authorMark Brown <broonie@kernel.org>2020-12-10 13:30:11 +0000
committerMark Brown <broonie@kernel.org>2020-12-10 13:30:11 +0000
commit49ab19a4a51a31cb06992386cec4be82ebca5a2d (patch)
treede7d31ec7ded2c8ab8dbdfe5a55fa283068023d0 /arch/x86/kernel/dumpstack.c
parentb0dfd948379c79b8754e224e29b99d30ce0d79b8 (diff)
parent3b25f337929e73232f0aa990cd68a129f53652e2 (diff)
Merge series "spi: spi-geni-qcom: Use gpio descriptors for CS" from Stephen Boyd <swboyd@chromium.org>:
Collected patches from the two series below and associated tags so they can be merged in one pile through the spi tree. Merry December! SPI: https://lore.kernel.org/r/20201202214935.1114381-1-swboyd@chromium.org cros-ec: https://lore.kernel.org/r/20201203011649.1405292-1-swboyd@chromium.org Cc: Akash Asthana <akashast@codeaurora.org> Cc: Simon Glass <sjg@chromium.org> Cc: Gwendal Grignou <gwendal@chromium.org> Cc: Douglas Anderson <dianders@chromium.org> Cc: Alexandru M Stan <amstan@chromium.org> Stephen Boyd (3): platform/chrome: cros_ec_spi: Don't overwrite spi::mode platform/chrome: cros_ec_spi: Drop bits_per_word assignment spi: spi-geni-qcom: Use the new method of gpio CS control drivers/platform/chrome/cros_ec_spi.c | 2 -- drivers/spi/spi-geni-qcom.c | 1 + 2 files changed, 1 insertion(+), 2 deletions(-) base-commit: b65054597872ce3aefbc6a666385eabdf9e288da -- https://chromeos.dev
Diffstat (limited to 'arch/x86/kernel/dumpstack.c')
-rw-r--r--arch/x86/kernel/dumpstack.c23
1 files changed, 19 insertions, 4 deletions
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 25c06b67e7e0..97aa900386cb 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -78,6 +78,9 @@ static int copy_code(struct pt_regs *regs, u8 *buf, unsigned long src,
if (!user_mode(regs))
return copy_from_kernel_nofault(buf, (u8 *)src, nbytes);
+ /* The user space code from other tasks cannot be accessed. */
+ if (regs != task_pt_regs(current))
+ return -EPERM;
/*
* Make sure userspace isn't trying to trick us into dumping kernel
* memory by pointing the userspace instruction pointer at it.
@@ -85,6 +88,12 @@ static int copy_code(struct pt_regs *regs, u8 *buf, unsigned long src,
if (__chk_range_not_ok(src, nbytes, TASK_SIZE_MAX))
return -EINVAL;
+ /*
+ * Even if named copy_from_user_nmi() this can be invoked from
+ * other contexts and will not try to resolve a pagefault, which is
+ * the correct thing to do here as this code can be called from any
+ * context.
+ */
return copy_from_user_nmi(buf, (void __user *)src, nbytes);
}
@@ -115,13 +124,19 @@ void show_opcodes(struct pt_regs *regs, const char *loglvl)
u8 opcodes[OPCODE_BUFSIZE];
unsigned long prologue = regs->ip - PROLOGUE_SIZE;
- if (copy_code(regs, opcodes, prologue, sizeof(opcodes))) {
- printk("%sCode: Unable to access opcode bytes at RIP 0x%lx.\n",
- loglvl, prologue);
- } else {
+ switch (copy_code(regs, opcodes, prologue, sizeof(opcodes))) {
+ case 0:
printk("%sCode: %" __stringify(PROLOGUE_SIZE) "ph <%02x> %"
__stringify(EPILOGUE_SIZE) "ph\n", loglvl, opcodes,
opcodes[PROLOGUE_SIZE], opcodes + PROLOGUE_SIZE + 1);
+ break;
+ case -EPERM:
+ /* No access to the user space stack of other tasks. Ignore. */
+ break;
+ default:
+ printk("%sCode: Unable to access opcode bytes at RIP 0x%lx.\n",
+ loglvl, prologue);
+ break;
}
}